Archives of Foundry Engineering

This study shows the results of the investigation of the strength performance, and residual strength of a single component inorganic binder

system Cast Clean S27®. The study was conducted using three different foundry sand sources in South Africa. Sample A is an alluvial

coastal sample, sample B is an alluvial riverbed sample and Sample C is a blasted sample from a consolidated quartzite rock. The binder

was also cured using three different curing mechanisms. The aim of the investigation was to determine the variation of strength

performance and residual strength between the different South African sand sources based upon the physical and chemical properties of

the sand sources. The moulding sand was prepared using three possible curing mechanisms which are carbon dioxide curing, ester curing

and heat curing. The strength measurements were determined by bending strength. Sample A and sample C sand had good strength

development. Sample B sand had inferior strength development and excellent high temperature residual strength. The study showed that

the single component inorganic binders have good strength development and low residual strength. The silica sand properties have major

contributing factors on both strength development and residual strength. The degree of influence of silica sand properties on strength

performance and residual strength is dependent on the time of curing and method of curing.

A special Slag-Prop Cu database has been developed to archive data from laboratory and industrial tests related to post-reduction slags. In

order to enrich the data areas, it was decided to design a system for measuring the temperature of the liquid slag and its viscosity. Objectives

of research work are to gather information on the properties of post-slags such as the temperature of liquid slag and its viscosity. The

discussed issues are especially important in the foundry practice. Designed research stand and using of database applications can greatly

facilitate the work of metallurgists, foundrymen, technologists and scientists. The viscosity measurement was developed and presented

earlier. The author's analytical methodology was supplemented by a thyristor measuring system (described in the article). The system

temperature measurement can be performed simultaneously in 3 ways to reduce the measurement error. Measurement of the voltage mV -

using the Seebeck effect can be measured throughout the entire range of thermocouple resistance, up to 1300 °C. Direct temperature

measurement ⁰C - measurement only below 1000 ⁰C. Additional measurement - the measurement can also be read from the pyrometer set

above the bath. The temperature and the reading frequency depend on the device itself. The principle of measurement is that in a molten

metal / slag crucible, we put a N-type thermocouple. The thermocouples are hung by means of a tripod above the crucible and placed in a

crucible. The thermocouple is connected to a compensating line dedicated to this type of thermocouple. The cable is in turn connected to a

special multimeter that has the ability to connect to a computer and upload results. Temperature measurement can be performed

simultaneously in 3 ways to reduce the measurement error. The Sn-Pb alloy has been subjected to testing for proper operation of the device.

In this foot should be observed the supercooling of the liquid, which initiates the crystallization process and in which latent heat begins to

exude raising the temperature until the coagulation temperature is reached.

Paper presents the results of research on modified surface grain refinement method used in investment casting of hollow, thin-walled parts

made of nickel based superalloys. In the current technology, the refining inoculant is applied to the surface of the wax pattern and then, it

is transferred to the ceramic mould surface during dewaxing. Because of its chemical activity the inoculant may react with the liquid metal

which can cause defects on the external surface of the cast part. The method proposed in the paper aims to reduce the risk of external

surface defects by applying the grain refiner only to the ceramic core which shapes the internal surface of the hollow casting. In case of

thin-walled parts the grain refinement effect is visible throughout the thickness of the walls. The method is meant to be used when internal

surface finish is less important, like for example, aircraft engine turbine blades, where the hollowing of the cast is mainly used to lower the

weight and aid in cooling during operation.

Pouring of liquid aluminium is typically accompanied by disturbance of the free surface. During these disturbances, the free surface oxide

films can be entrained in the bulk of liquid, also pockets of air can be accidentally trapped in this oxide films. The resultant scattering of

porosity in castings seems nearly always to originate from the pockets of entrained air in oxide films. Latest version of ProCast software

allows to identify the amount of oxides formed at the free surface and where they are most likely to end-up in casts. During a filling

calculation, ProCast can calculate different indicators which allow to better quantify the filling pattern. The fluid front tracking indicator “

Free surface time exposure” has the units [cm2*s]. At each point of the free surface, the free surface area is multiplied by the time. This

value is cumulated with the value of the previous timestep. In addition, this value is transported with the free surface and with the fluid

flow.Experiments to validate this new functions were executed.

Core sands for blowing processes, belong to these sands in which small amount of the applied binding material has the ability of covering

the sand matrix surface in a way which - at relatively small coating thickness - allows to achieve the high strength. Although the deciding

factor constitute, in this aspect, strength properties of a binder, its viscosity and ability to moisten the matrix surface, the essential meaning

for the strength properties of the prepared moulding sand and the mould has the packing method of differing in sizes sand grains with the

coating of the binding material deposited on their surfaces.

The knowledge of the influence of the compaction degree of grains forming the core on the total contact surface area can be the essential

information concerning the core strength.

Forecasting the strength properties of core sands, at known properties of the applied chemically hardened binder and the quartz matrix,

requires certain modifications of the existing theoretical models. They should be made more realistic with regard to assumptions

concerning grain sizes composition of quartz sands and the packing structure deciding on the active surface area of the contacts between

grains of various sizes and - in consequence - on the final strength of cores.

Various examples of the design of cast elements of the equipment used in furnaces for the heat treatment of machine parts are given.

Shortcomings in their performance are indicated. Reasons for required stability of equipment are briefly discussed. Elements of equipment

illustrate the possibilities of using a charge-carrying pallet with dimensions of 900×600×45 mm as a basis for multi-component

technological equipment. Introducing additional elements, such as metal baskets, intermediate pallets or crossbars to the main pallet, it

becomes possible to create different configurations of this equipment. The technological equipment presented and discussed here is offered

to different plants which heat-treat a wide variety of produced parts. It was found that the reliability and durability of new designed

equipment can be checked only during practical use. For large plants dealing with the heat treatment of bulk quantities of parts

homogeneous or similar in shape is recommended to use the dedicated tooling.

Diagnostics of composite castings, due to their complex structure, requires that their characteristics are tested by an appropriate description

method. Any deviation from the specific characteristic will be regarded as a material defect. The detection of defects in composite castings

sometimes is not sufficient and the defects have to be identified. This study classifies defects found in the structures of saturated metallic

composite castings and indicates those stages of the process where such defects are likely to be formed. Not only does the author

determine the causes of structural defects, describe methods of their detection and identification, but also proposes a schematic procedure

to be followed during detection and identification of structural defects of castings made from saturated reinforcement metallic composites.

Alloys examination was conducted after technological process, while using destructive (macroscopic tests, light and scanning electron

microscopy) and non-destructive (ultrasonic and X-ray defectoscopy, tomography, gravimetric method) methods. Research presented in

this article are part of author’s work on castings quality.

The article describes the trend towards increased use of induction crucible furnaces for cast iron smelting. The use of gas cupola’s duplex

process – induction crucible furnace – has been proved the effective direction of scientific and technical advance in the foundry industry.

Gas cupolas and induction furnaces are used for cast iron smelting at the Penza Compressor Plant where in the 1960s the author developed

and introduced gas cupolas for the first time in the world. In the article, the author represents the findings of the investigation on

thermodynamics of crucible reduction of silicon, which is pivotal when choosing the technological mode for cast iron smelting in

induction furnaces. The author proposes a new reaction crucible diagram with due account of both partial pressure and activity of the

components involved into the process. For the first time ever, the electrochemical mechanism of a crucible reaction has been studied and

the correctness of the proposed diagram has been confirmed.

The paper presents the capabilities of welding techniques to creating properties of wear resistant high chromium cast iron alloy. The use

of the right kind of welding sequence allows you to change the structure and properties of the obtained welds. Tests were conducted for

one type of additive material in the form of self shielded core wire. In order to determine the effect of the type of welding sequence on the

properties of welds performed welding using string bead and weave bead. The resulting weld was tested on hardness and research structure

in an optical microscope. In the following studies have been made erosive tests wear of made hardfacing. String beads gave structure rich

in carbides and harder about 270 HV of the weld with weave bead. Also, wear resistance was nearly twice as better for welds made with

string beads. In the experiment a decisive role in the resistance to wear plays a high hardness of the deposit and the presence of carbides in

its structure. Changes in the basic parameters of the deposition process allows for the formation of structure and properties of hardfacing

welds in a wide range.

The paper presents research on the effects of soft annealing parameters on a change of the impact strength KC and Brinell hardness (HB)

of the EN AC-AlSi11 alloy. The research has been performed according to the trivalent testing plan for two input parameters –

temperature in the range between 280°C and 370°C and time in the range between 2 and 8 hours. The application of such heat treatment

improves the plasticity of the investigated alloy. The improvement of the impact strength KC by 71% and the decrease of the hardness HB

by 20% was achieved for the soft annealing treatment conducted at a temperature 370°C for 8 hours, compared to the alloy without the

heat treatment. A change of the form of eutectic silicon precipitations which underwent refinement, coagulation and partial rounding, had

a direct effect on the hardness HB and impact strength KC. The results obtained were used to prepare space plots enabling the temperature

and time for soft annealing treatment to be selected with reference to the obtained impact strength KC and hardness HB of the alloy with

the heat treatment.

This article presents the results of investigations of the effect of heat treatment temperature on the content of the carbide phase of HS3-1-2

and HS6-5-2 low-alloy high-speed steel. Analysis of the phase composition of carbides is carried out using the diffraction method. It is

determined that with increasing austenitising temperature, the intensification of dissolution of M6C carbide increases. As a result, an

increase in the grain size of the austenite and the amount of retained austenite causes a significant reduction in the hardness of hardened

steel HS3-1-2 to be observed. The results of diffraction investigations showed that M7C3 carbides containing mainly Cr and Fe carbides

and M6C carbides containing mainly Mo and W carbides are dissolved during austenitisation. During austenitisation of HS3-1-2 steel, the

silicon is transferred from the matrix to carbides, thus replacing carbide-forming elements. An increase in a degree of tempering leads to

intensification of carbide separation and this process reduce the grindability of tested steels.

This paper discusses changes in the microstructure and abrasive wear resistance of G17CrMo5-5 cast steel modified with rare earth metals

(REM). The changes were assessed using scanning microscopy. The wear response was determined in the Miller test to ASTM G75.

Abrasion tests were supplemented with the surface profile measurements of non-modified and modified cast steel using a Talysurf CCI

optical profilometer. It was demonstrated that the modification substantially affected the microstructure of the alloy, leading to grain size

reduction and changed morphology of non-metallic inclusions. The observed changes in the microstructure resulted in a three times higher

impact strength (from 33 to 99 kJ/cm2

) and more than two times higher resistance to cracking (from 116 to 250 MPa). The following

surface parameters were computed: Sa: Arithmetic mean deviation of the surface, Sq: Root-mean-square deviation of the surface, Sp:

Maximum height of the peak

Sv: Maximum depth of the valley, Sz: Ten Point Average, Ssk: Asymmetry of the surface, Sku: Kurtosis of the surface. The findings also

indicated that the addition of rare earth metals had a positive effect on the abrasion behaviour of G17CrMo5-5 cast steel.

The paper presents a practical example of improving quality and occupational safety on automated casting lines. Working conditions

on the line of box moulding with horizontal mould split were analysed due to low degree of automation at the stage of cores or filters

installation as well as spheroidizing mortar dosing. A simulation analysis was carried out, which was related to the grounds of introducing

an automatic mortar dispenser to the mould. To carry out the research, a simulation model of a line in universal Arena software

for modelling and simulation of manufacturing systems by Rockwell Software Inc. was created. A simulation experiment was carried out

on a model in order to determine basic parameters of the working system. Organization and working conditions in other sections of the line

were also analysed, paying particular attention to quality, ergonomics and occupational safety. Ergonomics analysis was carried out

on manual cores installation workplace and filters installation workplace, and changes to these workplaces were suggested in order

to eliminate actions being unnecessary and onerous for employees.

The paper presents the results of research of impact strength of aluminum alloy EN AC-44200 based composite materials reinforced with

alumina particles. The research was carried out applying the materials produced by the pressure infiltration method of ceramic preforms

made of Al2O3 particles of 3-6m with the liquid EN AC-44200 Al alloy. The research was aimed at determining the composite resistance

to dynamic loads, taking into account the volume of reinforcing particles (from 10 to 40% by volume) at an ambient of 23°C and at

elevated temperatures to a maximum of 300°C. The results of this study were referred to the unreinforced matrix EN AC-44200 and to its

hardness and tensile strength. Based on microscopic studies, an analysis and description of crack mechanics of the tested materials were

performed. Structural analysis of a fracture surface, material structures under the crack surfaces of the matrix and cracking of the

reinforcing particles were performed.

The paper presents the research results of the solenoid housing made of the Zn4Al1Cu alloy that was destroyed as a result of corrosion.

Surface of the tested part showed macroscopically the features typical for white corrosion, and the resulting corrosion changes led to a

disturbance of the alloy cohesion. The research performed have shown that the tested solenoid valve has intergranular corrosion as a

reaction of the environment containing road salt. The corrosion was initiated in the areas of the alfa phase existence appearing in the

eutectic areas which propagated over dendritic areas of the alloy. Initiation of the corrosion followed as a result of the galvanic effect of

the alfa phase reach in aluminium showing higher electrochemical potential, in contact with the eta phase reach in zinc. The impact of the

phase reach in lead present in the microstructure on the corrosion processes run was not found.

Within the presented research, effect of annealing on nature of corrosion damages of medium-nickel austenitic nodular cast iron castings,

containing 5.5% to 10.3% Ni, was determined. Concentration of nickel, lower than in the Ni-Resist cast iron, was compensated with

additions of other austenite-stabilising elements (manganese and copper). In consequence, raw castings with austenitic matrix structure and

gravimetrically measured corrosion resistance increasing along with nickel equivalent value EquNi were obtained. Annealing of raw

castings, aimed at obtaining nearly equilibrium structures, led to partial austenite-to-martensite transformation in the alloys with EquNi

value of ca. 16%. However, corrosion resistance of the annealed alloys did not decrease in comparison to raw castings. Annealing of

castings with EquNi value above 18% did not cause any structural changes, but resulted in higher corrosion resistance demonstrated by

smaller depth of corrosion pits.

The article summarizes the theoretical knowledge from the field of brazing of graphitic cast iron, especially by means of conventional

flame brazing using a filler metal based on CuZn (CuZn40SnSi – brass alloy). The experimental part of the thesis presents the results of

performance assessment of brazed joints on other than CuZn basis using silicone (CuSi3Mn1) or aluminium bronze (CuAl10Fe). TIG

electrical arc was used as a source of heat to melt these filler materials. The results show satisfactory brazed joints with a CuAl10Fe filler

metal, while pre-heating is not necessary, which favours this method greatly while repairing sizeable castings. The technological procedure

recommends the use of AC current with an increased frequency and a modified balance between positive and negative electric arc polarity

to focus the heat on a filler metal without melting the base material. The suitability of the joint is evaluated on the basis of visual

inspection, mechanic and metallographic testing.

The paper presents results of initial research on the possibility of applying microwave radiation in an innovative process of making casting

moulds from silica sand, where gypsum CaSO4∙2H2O was acting as a binding material. In the research were compared strengths and

technological properties of moulding mixture subjected to: natural bonding process at ambient temperature or natural curing with

additional microwave drying or heating with the use of microwaves immediately after samples were formed. Used in the research

moulding sands, in which dry constituents i.e. sand matrix and gypsum were mixed in the ratio: 89/11. On the basis of the results of

strength tests which were obtained by various curing methods, beneficial effect of using microwaves at 2.45 GHz for drying up was

observed after 1, 2 and 5 hours since moisture sandmix was formed. Applying the microwaves for hardening just after forming the samples

guarantees satisfactory results in the obtained mechanical parameters. In addition, it has been noted that, from a technological and

economic point of view, drying the silica sand with gypsum binder in microwave field can be an alternative to traditional molding sand

technologies.

The paper deals with the impact of technological parameters on the mechanical properties and microstructure in AlSi12 alloy

using squeeze casting technology. The casting with crystallization under pressure was used, specifically direct squeeze

casting method. The goal was to affect crystallization by pressure with a value 100 and 150 MPa. From the experiments we

can conclude that operating pressure of 100 MPa is sufficient to influence the structural characteristics of the alloy AlSi12.

The change in cooling rate influences the morphology of the silicon particles and intermetallic phases. A change of excluded

needles to a rod-shaped geometries with significantly shorter length occurs when used gravity casting method. At a pressure

of 100 MPa was increased of tensile strength on average of 20%. At a pressure of 150 MPa was increased of tensile strength

on average of 30%. During the experiment it was also observed, that increasing difference between the casting temperature

and the mold temperature leads to increase of mechanical properties.

The FMEA (Failure Mode and Effects Analysis) method consists in analysis of failure modes and evaluation of their effects based on

determination of cause-effect relationships for formation of possible product or process defects. Identified irregularities which occur

during the production process of piston castings for internal combustion engines were ordered according to their failure rates, and using

Pareto-Lorenz analysis, their per cent and cumulated shares were determined. The assessments of risk of defects occurrence and their

causes were carried out in ten-point scale of integers, while taking three following criteria into account: significance of effects of the defect

occurrence (LPZ), defect occurrence probability (LPW) and detectability of the defect found (LPO). A product of these quantities

constituted the risk score index connected with a failure occurrence (a so-called “priority number,” LPR). Based on the observations of the

piston casting process and on the knowledge of production supervisors, a set of corrective actions was developed and the FMEA was

carried out again. It was shown that the proposed improvements reduce the risk of occurrence of process failures significantly, translating

into a decrease in defects and irregularities during the production of piston castings for internal combustion engines.

Lead-free alloys containing various amounts of zinc (4.5%, 9%, 13%) and constant copper addition (1%) were discussed. The results of

microstructure examinations carried out by light microscopy (qualitative and quantitative) and by SEM were presented. In the light

microscopy, a combinatorial method was used for the quantitative evaluation of microstructure. In general, this method is based on the

phase quanta theory according to which every microstructure can be treated as an arrangement of phases/structural components in the

matrix material. Based on this method, selected geometrical parameters of the alloy microstructure were determined. SEM examinations

were based on chemical analyses carried out in microregions by EDS technique. The aim of the analyses was to identify the intermetallic

phases/compounds occurring in the examined alloys. In fatigue testing, a modified low cycle fatigue test method (MLCF) was used. Its

undeniable advantage is the fact that each time, using one sample only, several mechanical parameters can be estimated. As a result of

structure examinations, the effect of alloying elements on the formation of intermetallic phases and compounds identified in the examined

lead-free alloys was determined. In turn, the results of mechanical tests showed the effect of intermetallic phases identified in the

examined alloys on their fatigue life. Some concepts and advantages of the use of the combinatorial and MLCF methods in materials

research were also presented.

This article presents the methodology for exploratory analysis of data from microstructural studies of compacted graphite iron to gain

knowledge about the factors favouring the formation of ausferrite. The studies led to the development of rules to evaluate the content of

ausferrite based on the chemical composition. Data mining methods have been used to generate regression models such as boosted trees,

random forest, and piecewise regression models. The development of a stepwise regression modelling process on the iteratively limited

sets enabled, on the one hand, the improvement of forecasting precision and, on the other, acquisition of deeper knowledge about the

ausferrite formation. Repeated examination of the significance of the effect of various factors in different regression models has allowed

identification of the most important variables influencing the ausferrite content in different ranges of the parameters variability.

The method of determining the accuracy of polymer molds in plaster forms has been discussed. Distortion of the surface of molds and

plaster molds has been assessed. It has been found that the presence of monolithic and porous structure in the samples does not change the

accuracy of the surfaces when forms are prepared for removing the material of the model. It has been found that in case of full-mold

casting it is more expedient to form the mold cavity with cellular adjustable structures of molding prototypes.

Moulding sands containing sodium silicate (water-glass) belong to the group of porous mixture with low resistance to increased humidity.

Thanks to hydrophilic properties of hardened or even overheated binder, possible is application of effective methods of hydrous

reclamation consisting in its secondary hydration. For the same reason (hydrophilia of the binder), moulds and foundry cores made of

high-silica moulding sands with sodium silicate are susceptible to the action of components of atmospheric air, including the contained

steam. This paper presents results of a research on the effect of (relative) humidity on mechanical and technological properties of

microwave-hardened moulding mixtures. Specimens of the moulding sand containing 1.5 wt% of sodium water-glass with module 2.5

were subjected, in a laboratory climatic chamber, to long-term action of steam contained in the chamber atmosphere. Concentration of

water in atmospheric air was stabilized for 28 days (672 h) according to the relative humidity parameter that was ca. 40%, 60% and 80% at

constant temperature 20 °C. In three cycles of the examinations, the specimens were taken out from the chamber every 7 days (168 h) and

their mechanical and technological parameters were determined. It was found on the grounds of laboratory measurements that moulds and

cores hardened with microwaves are susceptible to action of atmospheric air and presence of water (as steam) intensifies action of the air

components on glassy film of sodium silicate. Microwave-hardened moulding sands containing sodium silicate may be stored on a longterm

basis in strictly determined atmospheric conditions only, at reduced humidity. In spite of a negative effect of steam contained in the

air, the examined moulding mixtures maintain a part of their mechanical and technological properties, so the moulds and foundry cores

stored in specified, controlled conditions could be still used in manufacture.

In the paper, we present a coordinated production planning and scheduling problem for three major shops in a typical alloy casting

foundry, i.e. a melting shop, molding shop with automatic line and a core shop. The castings, prepared from different metal, have different

weight and different number of cores. Although core preparation does not required as strict coordination with molding plan as metal

preparation in furnaces, some cores may have limited shelf life, depending on the material used, or at least it is usually not the best

organizational practice to prepare them long in advance. Core shop have limited capacity, so the cores for castings that require multiple

cores should be prepared earlier. We present a mixed integer programming model for the coordinated production planning and scheduling

problem of the shops. Then we propose a simple Lagrangian relaxation heuristic and evolutionary based heuristic to solve the coordinated

problem. The applicability of the proposed solution in industrial practice is verified on large instances of the problem with the data

simulating actual production parameters in one of the medium size foundry.

This article deals with the fatigue properties of newly used AlZn10Si8Mg aluminium alloy where the main aim was to determine the

fatigue strength and compare it with the fatigue strength of AlSi7Mg0.3 secondary aluminium alloys which is used in the automotive

industry for cyclically loaded components. AlZn10Si8Mg aluminium alloy, also called UNIFONT 90, is self-hardening (without heat

treatments), which contributes to economic efficiency. This is one of the main reasons why is compared, and may be an alternative

replacement for AlSi7Mg0.3 alloy which is heat treated to achieve required mechanical properties. The experiment results show that the

fatigue properties of AlZn10Si8Mg alloy are comparable, if not better, than AlSi7Mg0.3 alloy. Fatigue properties of AlZn10Si8Mg alloy

are achieved after seven days of natural ageing, immediately after casting and achieving value of fatigue strength is caused by structural

components formed during solidification of the melt.

The paper presents the technology and organization of the artistic cast production. On the basis of the actual cast production system, the

manufacturing process was shown, in particular sand–piece moulding, which is a very important process and a time-consuming part of the

entire manufacture of the casts. The current state of the production process as well as the organization of the work and production

technology were analysed with the use of methods and techniques of production improvement, the Lean Manufacturing concept and

computer systems. The results of the analysis and studies were shown with use of schemes and graphs of the layout of the production

resources, a flow chart of the production process, value stream mapping, and a costs table for the production and modernization of the

moulding stage. The work has shown that there are possibilities to improve the artistic cast production system. This improvement leads to

increased productivity, lower production costs of artistic casts and increased competitiveness of the foundry.

Different methods are used for production of bronze bearings. In terms of technical specifications, the success of each of these methods

depends on the bond’s strength and in terms of economic, the production method is important. In this study, the aim is to study the strength

and microstructure of steel-bronze thrust bearing bond that has been produced through the casting using pre-mold. In this study, in order to

bond, the raw metals are chemically washed with sulfuric acid solution for five minutes at first. Then, the molten bronze SAE660 is cast in

a structural steel S235JR pre-mold. The bond’s strength has been measured using the shear test three times; the measurement of bond’s

length has been done using field emission scanning electron microscope (FESEM). The results indicate that the strength of the bond is at

least 94.8 MPa and bond’s length is 0.45 micrometers. Therefore, this method was successful for trust bearing application.

Eutectoid growth, as the important reaction mechanism of the carbon steel heat treatment, is the basis to control the microstructure and

performance. At present, most studies have focused on lamellar growth, and did not consider the nucleation process. Mainly due to the

nucleation theory is inconclusive, a lot of research can support their own theory in a certain range. Based on the existing nucleation theory,

this paper proposes a cooperative nucleation model to simulate the nucleation process of eutectoid growth. In order to ensure that the

nucleation process is more suitable to the theoretical results, different correction methods were used to amend the model respectively. The

results of numerical simulation show that when the model is unmodified, the lateral growth of single phase is faster than that of

longitudinal growth, so the morphology is oval. Then, the effects of diffusion correction, mobility correction and ledges nucleation

mechanism correction on the morphology of nucleation and the nucleation rate were studied respectively. It was found that the

introduction of boundary diffusion and the nucleation mechanism of the ledges could lead to a more realistic pearlite.

Among the family of stainless steels, cast austenitic stainless steels (CASSs) are preferably used due to their high mechanical properties

and corrosion resistance. These steels owe their properties to their microstructural features consisting of an austenitic matrix and skeletal

or lathy type δ-ferrite depending on the cooling rate. In this study, the solidification behavior of CASSs (304L and 316L grades) was

studied using ThermoCalc software in order to determine the solidification sequence and final microstructure during cooling. Theoretical

findings were supported by the microstructural examinations. For the mechanical characterization, not only hardness measurements but

also tribological studies were carried out under dry sliding conditions and worn surfaces were examined by microscopy and 3D

profilometric analysis. Results were discussed according to the type and amount of microstructural features.

In this study T6 heat treated 6063 aluminum alloys were used as substrate material. In order to form a bond between the substrate and the

main coating, all samples were coated with Ni-Cr-Al powders. 8 wt% Yttria Stabilized Zirconia powders (YSZ) were coated with plasma

spray technique. Thickness of YSZ was 150 m and bond coating was 36 m. XRD and SEM-EDS analyses were performed to characterize

the coating layers. These YSZ coated and uncoated samples were subjected to wear testing under different spindle speed, loading and

working distance. Wear test results were compared with the kinetic friction coefficients and weight loss values. Wear marks on YSZ

coated and uncoated samples were investigated by SEM analysis. By coating with plasma spray technique, the wear resistance of Al alloys

was increased without changing the friction coefficient. It was found that spindle speed had significant effect over the wear properties than

the load applied. By YSZ coating, wear properties were increased 10 times.

This study characterizes the bronze jewellery recovered from the Lusatian culture urn-field in Mała Kępa (Chełmno land, Poland). Among

many common ornaments (e.g. necklaces, rings, pins) the ones giving evidence of a steppe-styled inspiration (nail earrings) were also

identified. With the dendritic microstructures revealed, the nail earrings prove the implementing of a lost-wax casting method, whereas

some of the castings were further subjected to metalworking. The elemental composition indicates the application of two main types of

bronze alloys: Cu-Sn and Cu-Sn-Pb. It has been established that the Lusatian metalworkers were familiar with re-melting the scrap bronze

and made themselves capable of roasting the sulphide-rich ores.

The collection from Mała Kępa has been described in terms of its structure and composition. The investigations were made by means of

the energy dispersive X-ray fluorescence spectroscopy (ED-XRF), scanning electron microscopy (SEM) coupled with an energy dispersive

X - ray analysis system (EDS) and optical microscopy (OM). In order to fingerprint an alloy profile of the castings with a special emphasis

on the nail earrings, the data-set (ED-XRF, EDS) was statistically evaluated using multidimensional analyses (FA, DA).

During excavation of the cremation cemetery of urnfield culture in Legnica at Spokojna Street (Lower Silesia, Poland), dated to 1100-700

BC, the largest - so far in Poland – a collection of casting moulds from the Bronze Age was discovered: three moulds for axes casting

made out of stone and five moulds for casting sickles, razors, spearhead and chisels, made out of clay. This archaeological find constituted

fittings of foundrymen’s graves. In order to perform the complete analysis of moulds in respect of their application in the Bronze Age

casting technology analytical methods, as well as, computer aided methods of technological processes were used. Macroscopic

investigations were performed and the X-ray fluorescence spectrometry method was used to analyse the chemical composition and metal

elements content in mould cavities. Moulds were subjected to three-dimensional scanning and due to the reverse engineering the geometry

of castings produced in these moulds were obtained.

The gathered data was used to perform design and research works by means of the MAGMA5

software. Various variants of the pouring

process and alloys solidification in these archaeological moulds were simulated. The obtained results were utilised in the interpretation of

the Bronze Age casting production in stone and clay moulds, with regard to their quality and possibility of casting defects occurrence

being the result of these moulds construction.

The reverse engineering, modelling and computer simulation allowed the analysis of moulds and castings. Investigations of casting moulds

together with their digitalisation and reconstruction of casting technology, confirm the high advancement degree of production processes

in the Bronze Age.

There are two methods to produce primary copper: hydrometallurgical and pyrometallurgical. Copper concentrates, from which copper

matte is melted, constitute the charge at melting primary copper in the pyrometallurgical process. This process consists of a few stages, of

which the basic ones are roasting and smelting. Smelting process may be bath and flash. Slag from copper production, on the end of

process contain less 0,8%. It is treat as a waste or used other field, but only in a few friction. The slag amount for waste management or

storage equaled 11 741 – 16 011 million tons in 2011. This is a serious ecological problem. The following slags were investigated: slag

originated from the primary copper production process in the flash furnace of the Outtokumpuja Company in HM Głogów 2 (Sample S2):

the same slag after the copper removal performed according the up to now technology (Sample S1): slag originated from the primary

copper production process in the flash furnace of the Outtokumpuja Company in HM Głogów 2, after the copper removal performed

according the new technology (Sample S3). In practice, all tested slags satisfy the allowance criteria of storing on the dumping grounds of

wastes other than hazardous and neutral.

The paper refers to previous publications of the author, focused on criteria of casting feeding, including the thermal criterion proposed by

Niyama. On the basis of this criterion, present in the post-processing of practically all the simulation codes, danger of casting compactness

(in the sense of soundness) in form of a microporosity, caused by the shrinkage phenomena, is predicted. The vast majority of publications

in this field concerns shrinkage and feeding phenomena in the cast steel castings – these are the alloys, in which parallel expansion

phenomenon does not occur as in the cast irons (graphite crystallization). The paper, basing on the simulation-experimental studies,

presents problems of usability of a classic, definition-based approach to the Niyama criterion for the cast iron castings, especially of

greater massiveness, for prediction of presence of zones of dispersed porosity, with relation to predictions of the shrinkage type defects.

The graphite expansion and its influence on shrinkage compensation during solidification of eutectic is also discussed.

The ceaseless progress of nanotechnology, observed in the last years, causes that nanomaterials are more and more often applied in several

fields of industry, technique and medicine. E.g. silver nanoparticles are used in biomedicine for disinfection and polymer nanoparticles

allow insulin transportation in pharmacology. New generation materials containing nanoparticles are also used in the chemical industry

(their participation in the commercial market equals app. 53 %). Nanomaterials are used in electronics, among others for semiconductors

production (e.g. for producing nanoink Ag, which conducts electric current).

Nanomaterials, due to their special properties, are also used in the foundry industry in metallurgy (e.g. metal alloys with nanocrystalline

precipitates), as well as in investment casting and in moulding and core sand technologies. Nanoparticles and containing them composites

are applied in several technologies including foundry practice, automotive industry, medicine, dentistry etc. it is expected that their role

and market share will be successively growing.

Inconel 713C precision castings are used as aircraft engine components exposed to high temperatures and the aggressive exhaust gas

environment. Industrial experience has shown that precision-cast components of such complexity contain casting defects like

microshrinkage, porosity, and cracks. This necessitates the development of repair technologies for castings of this type. This paper

presents the results of metallographic examinations of melted areas and clad welds on the Inconel 713C nickel-based superalloy, made by

TIG, plasma arc, and laser. The cladding process was carried out on model test plates in order to determine the technological and materialrelated

problems connected with the weldability of Inconel 713C. The studies included analyses of the macro- and microstructure of the

clad welds, the base materials, and the heat-affected zones. The results of the structural analyses of the clad welds indicate that Inconel

713C should be classified as a low-weldability material. In the clad welds made by laser, cracks were identified mainly in the heat-affected

zone and at the melted zone interface, crystals were formed on partially-melted grains. Cracks of this type were not identified in the clad

welds made using the plasma-arc method. It has been concluded that due to the possibility of manual cladding and the absence of welding

imperfections, the technology having the greatest potential for application is plasma-arc cladding.

Manganese is an effective element used for the modification of needle intermetallic phases in Al-Si alloy. These particles seriously

degrade mechanical characteristics of the alloy and promote the formation of porosity. By adding manganese the particles are being

excluded in more compact shape of “Chinese script” or skeletal form, which are less initiative to cracks as Al5FeSi phase. In the present

article, AlSi7Mg0.3 aluminium foundry alloy with several manganese content were studied. The alloy was controlled pollution for achieve

higher iron content (about 0.7 wt. % Fe). The manganese were added in amount of 0.2 wt. %, 0.6 wt. %, 1.0 wt. % and 1.4 wt. %. The

influence of the alloying element on the process of crystallization of intermetallic phases were compared to microstructural observations.

The results indicate that increasing manganese content (> 0.2 wt. % Mn) lead to increase the temperature of solidification iron rich phase

(TAl5FeSi) and reduction this particles. The temperature of nucleation Al-Si eutectic increase with higher manganese content also. At

adding 1.4 wt. % Mn grain refinement and skeleton particles were observed.

AISI 52100 bearing steels are commonly used in applications requiring high hardness and abrasion resistance. The bearing steels are

working under dynamic loads in service conditions and their toughness properties become important. In order to provide the desired

mechanical properties, various heat treatments (austenizing, quenching and tempering) are usually applied. In this study, AISI 52100

bearing steel samples were austenized at 900°C for ½ h and water quenched to room temperature. Then tempering was carried out at

795°C, 400°C and 200°C for ½ h. In order to investigate the effect of heat treatment conditions on wear behavior, dry friction tests were

performed according to ASTM G99-05 Standard with a ‘ball-on-disk’ type tribometer. The samples were tested against steel and ceramic

counterparts using the parameters of 100 m distance and 30 N load and 0.063 m/s rotational speed. After wear test, the surface

characterization was carried out using microscopy. Wear loss values were calculated using a novel optical method on both flat and

counterpart specimens.

High-alloy corrosion-resistant ferritic-austenitic steels and cast steels are a group of high potential construction materials. This is

evidenced by the development of new alloys both low alloys grades such as the ASTM 2101 series or high alloy like super or hyper duplex

series 2507 or 2707 [1-5]. The potential of these materials is also presented by the increasing frequency of sintered components made both

from duplex steel powders as well as mixtures of austenitic and ferritic steels [6, 7]. This article is a continuation of the problems presented

in earlier works [5, 8, 9] and its inspiration were technological observed problems related to the production of duplex cast steel.

The analyzed AISI A3 type cast steel is widely used in both wet exhaust gas desulphurisation systems in coal fired power plants as well as

in aggressive working environments. Technological problems such as hot cracking presented in works [5, 8], with are effects of the rich

chemical composition and phenomena occurring during crystallization, must be known to the technologists.

The presented in this work phenomena which occur during the crystallization and cooling of ferritic-austenitic cast steel were investigated

using numerical methods with use of the ThermoCalc and FactSage® software, as well with use of experimental thermal-derivative

analysis.