Archives of Foundry Engineering

While analyzing shape accuracy of ferroalloy precision castings in terms of ceramic moulds physical anisotropy, low-alloy steel castings

("cover") and cast iron ("plate") were included. The basic parameters in addition to the product linear shape accuracy are flatness

deviations, especially due to the expanded flat surface which is cast plate. For mentioned castings surface micro-geometry analysis was

also carried, favoring surface load capacity tp50 for Rmax = 50%.

Surface load capacity tp50 obtained for the cast cover was compared with machined product, and casting plate surface was compared with

wear part of the conveyor belt. The results were referred to anisotropy of ceramic moulds physical properties, which was evaluated by

studying ceramic moulds samples in computer tomography equipment Metrotom 800.

This paper presents the results of measurements of liquid metal fluidity and linear shrinkage of nickel alloy IN-713C in vacuum induction

melting furnace Balzers VSG-2. Because of limited volume of the furnace chamber special models for technological trials were designed

and constructed to fit in the mould of dimensions 170x95x100mm. Two different designs of test models were proposed: horizontal round

rods and modified spiral. Preliminary studies were carried out for alloys Al-Si. Horizontal round rods test was useful for evaluation of

fluidity of hypoeutectic silumin, however in case of nickel superalloy the mould cavity was completely filled in each test because of high

required pouring temperature. Positive results were obtained from the modified spiral test for all alloys used in the research. Relationship

between the linear shrinkage for the test rod and a specific indicator of contraction defined on a spiral was observed.

The results of some mechanical properties of four Mg-5Al-xRE-0.4Mn (x = 1 – 5) alloys are presented. The microstructure of

experimental alloys consisted of an α-Mg phase and an α+γ semi-divorced eutectic, Al11RE3 phase and an Al10RE2Mn7 intermetallic

compound. For gravity casting in metal mould alloys, Brinell hardness, impact strength, tensile and compression properties at ambient

temperature were determined. The performed mechanical tests allowed the author to determine the proportional influence of the mass

fraction of rare earth elements in the alloys on their tensile strength, yield strength, compression strength and Brinell hardness. The

impact strength of the alloys slightly decreases with a rise in the rare earth elements mass fraction.

The examined material comprised two grades of corrosion-resistant cast steel, namely GX2CrNiMoN25-6-3 and GX2CrNiMoCuN25-6-3-

3, used for example in elements of systems of wet flue gas desulphurisation in power industry. The operating conditions in media heated

up to 70°C and containing Cl- and SO4 ions and solid particles produce high erosive and corrosive wear.The work proposes an application

of the σ phase as a component of precipitation strengthening mechanism in order to increase the functional properties of the material.

The paper presents the results of examination of the kinetics of σ phase precipitation at a temperature of 800°C and at times ranging from

30 to 180 minutes. Changes in the morphology of precipitates of the σ phase were determined using the value of shape factor R.

Resistance to erosion-corrosion wear of duplex cast steel was correlated with the kinetics of sigma phase precipitating.

This article contains information concerning of the analysis the possibility of defining refinery qualities of the slag based thermo-physical

and thermo-dynamical data. It was showed the brass refining with the many-carbide reagents introduced in to the slag. The paper presents

the results of the structure analysis of the brass after carbide slag refining in the industrial conditions. The results of the macrostructure

analysis have confirmed the argument on high reducing effectiveness of manganese and aluminium carbide used during CuZn39Pb2 alloy

melting. The X-Ray microanalysis of the ingot cross-section has shown considerable discrepancies in the disposition of the inclusions.

This effects showed on the great influence of reduction melting condition in to the brass melting

The effects of filling the core box cavity and sand compaction in processes of core production by blowing methods (blowing, shooting)

depend on several main factors. The most important are: geometrical parameters of cavity and complexity of its shape, number,

distribution and shape of blowing holes feeding sands as well as the venting of a technological cavity. Values of individual parameters are

selected according to various criteria, but mostly they should be adjusted to properties of the applied core sand.

Various methods developed by several researchers, including the authors own attempts, allow to assess core sands properties on the basis

of special technological tests projecting the process into a laboratory scale. The developed criteria defining a degree or a filling ability

factor provide a better possibility of assessing the core sand behavior during flowing and core box filling, which indicate the value and

structure of the obtained compacting decisive – after hardening – for strength and permeability. The mentioned above aspects are analyzed

– on the basis of authors’ own examinations - in the hereby paper.

An initial assessment of the effectiveness of cast iron inoculation, performed by the method of impulse introducing the master alloy into

cast iron, is presented. The experiment was concerned with the hypoeutectic gray cast iron inoculated with either the Alinoc or the Barinoc

master alloy by means of an experimental device for pneumatic transportation. Examinations involved pneumatic injection of the

powdered inoculant carried in a stream of gaseous medium (argon) into the metal bath held in the crucible of an induction furnace. It was

found that the examined process is characterised by both high effectiveness and stability.

A significant part of the knowledge used in the production processes is represented with natural language. Yet, the use of that knowledge

in computer-assisted decision-making requires the application of appropriate formal and development tools. An interesting possibility is

created by the use of an ontology that is understandable both for humans and for the computer. This paper presents a proposal for

structuring the information about the foundry processes, based on the definition of ontology adapted to the physical structure of the

ongoing technological operations that make up the process of producing castings.

The results of investigations of moulding sands with an inorganic binder called GEOPOL, developed by the SAND TEAM Company are

presented in the paper. Hardeners of various hardening rates are used for moulding sands with this binder. The main aim of investigations

was determination of the influence of the hardening rate of moulding sands with the GEOPOL binder on technological properties of these

sands (bending strength, tensile strength, permeability and grindability). In addition, the final strength of moulding sands of the selected

compositions was determined by two methods: by splitting strength and shear strength measurements. No essential influence of the

hardening rate on such parameters as: permeability, grindability and final strength was found. However, the sand in which the slowest

hardener (SA 72) were used, after 1 hour of holding, had the tensile and bending strength practically zero. Thus, the time needed for taking

to pieces the mould made of such moulding sand will be 1.5 - 2 hours.

The presented in the paper investigations were aimed at the determination of the reclaimed material (obtained in the dry mechanical

reclamation process) addition influence on properties of moulding sands with hydrated sodium silicate modified by colloidal suspension

of zinc oxide nanoparticles in propanol. Nanoparticles originated from the thermal decomposition of alkaline zinc carbonate, were used.

The results of the reclamation of the spent moulding sand with hydrated sodium silicate performed in the AT-2 testing reclaimer are

presented in the paper. Both, spent sands from the Floster S technology and from the technology with the modified water-glass were

subjected to the reclamation processes. The following determinations of the reclaimed material were performed: pH reaction, acid demand,

ignition loss and Na2O content. The obtained reclaim was used as a matrix component of moulding sands with water-glass in the Floster S

technology, in which it constituted 60% and 50% of the sand matrix. The strength properties of the prepared moulding sands were

determined (bending strength Rg

u

, tensile strength Rm

u

) after samples storing times: 1h, 2h, 4h and 24 hours.

The article presents an analysis of the applicability of the Replicast CS process as an alternative to the investment casting process,

considered in terms of the dimensional accuracy of castings. Ceramic shell moulds were based on the Ekosil binder and a wide range of

ceramic materials, such as crystalline quartz, fused silica, aluminosilicates and zirconium silicate. The linear dimensions were measured

with a Zeiss UMC 550 machine that allowed reducing to minimum the measurement uncertainty.

This paper presents the results of studies of high-alloyed white cast iron modified with lanthanum, titanium, and aluminium-strontium. The

samples were taken from four melts of high-vanadium cast iron with constant carbon and vanadium content and near-eutectic

microstructure into which the tested inoculants were introduced in an amount of 1 wt% respective of the charge weight. The study

included a metallographic examinations, mechanical testing, as well as hardness and impact resistance measurements taken on the obtained

alloys. Studies have shown that different additives affect both the microstructure and mechanical properties of high-vanadium cast iron.

Ductile iron casts with a higher silicone content were produced. The austempering process of high silicone ductile iron involving different

austempering times was studied and the results presented. The results of metallographical observations and tensile strength tests were

offered. The obtained results point to the fact that the silicone content which is considered as acceptable in the literature may in fact be

exceeded. The issue is viewed as requiring further research.

The paper presents the method of preparing a composite slurry composed of AlSi11 alloy matrix and 10 vol.% of SiC particles, as well as

the method of its high-pressure die casting and the measurement results concerning the tensile strength, the yield point, the elongation and

hardness of the obtained composite. Composite castings were produced at various values of the piston velocity in the second stage of

injection, diverse intensification pressure values, and various injection gate width values. There were found the regression equations

describing the change of mechanical properties of the examined composite as a function of pressure die casting process parameters. The

conclusion gives the analysis and the interpretation of the obtained results.

The resistance of cast iron to abrasive wear depends on the metal abrasive hardness ratio. For example, hardness of the structural

constituents of the cast iron metal matrix is lower than the hardness of ordinary silica sand. Also cementite, the basic component of

unalloyed white cast iron, has hardness lower than the hardness of silica. Some resistance to the abrasive effect of the aforementioned

silica sand can provide the chromium white cast iron containing in its structure a large amount of (Cr, Fe)7C3 carbides characterised by

hardness higher than the hardness of the silica sand in question. In the present study, it has been anticipated that the white cast iron

structure will be changed by changing the type of metal matrix and the type of carbides present in this matrix, which will greatly expand

the application area of castings under the harsh operating conditions of abrasive wear. Moreover, the study compares the results of

abrasive wear resistance tests performed on the examined types of cast iron. Tests of abrasive wear resistance were carried out on a Miller

machine. Samples of standard dimensions were exposed to abrasion in a double to-and-fro movement, sliding against the bottom of

a trough filled with an aqueous abrasive mixture containing SiC + distilled water. The obtained results of changes in the sample weight

were approximated with a power curve and shown further in the study.

Studies were conducted on a zinc coating produced on the surface of ductile iron grade EN-GJS-500-7 to determine the eutectic grain

effect. For this purpose, castings with a wall thickness of 5 to 30 mm were made and the resulting structure was examined. To obtain a

homogeneous metal matrix, samples were subjected to a ferritising annealing treatment. To enlarge the reaction surface, the top layer was

removed from casting by machining. Then hot dip galvanising treatment was performed at 450°C to capture the kinetics of growth of the

zinc coating (in the period from 60 to 600 seconds). Analysing the test results it was found that within the same time of hot dip

galvanising, the differences in the resulting zinc coating thickness on samples taken from castings with different wall cross-sections were

small but could, particularly for shorter times of treatment, reduce the continuity of the alloyed layer of the zinc coating.

The paper presents the results of comparative tests of the fatigue properties conducted on two non-ferrous alloys designated as Al 6082 and

Al 7075 which, due to the satisfactory functional characteristics, are widely used as engineering materials. The fatigue tests were carried

out using a proprietary, modified low cycle test (MLCF). Particular attention was paid to the fatigue strength exponent b and fatigue

ductility exponent c. Based on the tests carried out, the results comprised within the range defined by the literature were obtained. These

results prove a satisfactory sensitivity of the method applied, its efficiency, the possibility of conducting tests in a fully economical way

and above all the reliability of the obtained results of the measurements. Thus, the thesis has been justified that the modified low cycle

fatigue test (MLCF) can be recommended as a tool used in the development of alloy characteristics within the range of low-cycle variable

loads

Directional solidification technique is an important research instrument to study solidification of metals and alloys. In the paper the model

[6,7,8] of directional solidification in special Artemis-3 facility was presented. The current work aimed to propose the ease and efficient

way in calibrating the facility. The introduced M coefficient allowed effective calibration and implementation of defined thermal

conditions. The specimens of AlSi alloys with Fe-rich intermetallics and especially deleterious β-Al5FeSi were processed by controlled

solidification velocity, temperature gradient and cooling rate.

Drops of molten cast iron were placed on moulding sand substrates. The composition of the forming gaseous atmosphere was examined. It

was found that as a result of the cast iron contact with water vapour released from the sand, a significant amount of hydrogen was evolved.

In all the examined moulding sands, including sands without carbon, a large amount of CO was formed. The source of carbon monoxide

was carbon present in cast iron. In the case of bentonite moulding sand with seacoal and sand bonded with furan resin, in the composition

of the gases, the trace amounts of hydrocarbons, i.e. benzene, toluene, styrene and naphthalene (BTX), appeared. As the formed studies

indicate much higher content of BTX at lower temperature it was concluded that the hydrocarbons are unstable in contact with molten

iron

Flake graphite cast iron was hot-dip coated with pure aluminium or aluminium alloys (AlSi11 and AlTi5). The study aimed at determining

the influence of bath composition on the thickness, microstructure and phase composition of the coatings. The analysis was conducted by

means of an optical microscope and a scanning electron microscope with an EDS spectrometer. It was found that the overall thickness of a

coating was greatly dependent on the chemical composition of a bath. The coatings consisted of an outer layer and an inner intermetallic

layer, the latter with two zones and dispersed graphite. In all the cases considered, the zone in the inner intermetallic layer adjacent to the

cast iron substrate contained the Al5Fe2 phase with small amount of silicon; the interface between this phase and the cast iron substrate

differed substantially, depending on the bath composition. In the coatings produced by hot-dipping in pure aluminium the zone adjacent to

the outer layer had a composition similar to that produced from an AlTi5 bath, the Al3Fe phase was identified in this zone. The Al3Fe also

contained silicon but its amount was lower than that in the Al5Fe2. In the coatings produced by hot-dipping in AlSi11, the zone adjacent to

the outer layer contained the Al3FeSi phase. The analysis results showed that when AlSi11 alloy was applied, the growth mode of the inner

layer changed from inwards to outwards. The interface between the Al5Fe2 phase and the cast iron substrate was flat and the zone of this

phase was very thin. Locally, there were deep penetrations of the Al5FeSi phase into the outer layer, and the interface between this phase

and the outer layer was irregular. Immersion in an AlTi5 bath caused that the inner intermetallic layer was thicker than when pure

aluminium or AlSi11 alloy baths were used; also, some porosity was observed in this layer; and finally, the interface between the inner

layer and the cast iron substrate was the most irregular.

In this study, a preliminary evaluation was made of the applicability ofthe signalsof the cutting forces, vibration and acoustic emission in

diagnosis of the hardness and microstructure of ausferritic ductile iron and tool edge wear rate during its machining. Tests were performed

on pearlitic-ferritic ductile iron and on three types of ausferritic ductile iron obtained by austempering at 400, 370 and 320⁰C for 180

minutes. Signals of the cutting forces (F), vibration (V) and acoustic emission (AE) were registered while milling each type of the cast iron

with a milling cutter at different degrees of wear. Based on individual signals from all the sensors, numerous measures were determined

such as e.g. the average or maximum signal value. It was found that different measures from all the sensors tested depended on the

microstructure and hardness of the examined material, and on the tool condition. Knowing hardness of the material and the cutting tool

edge condition, it is possible to determine the structure of the material .Simultaneous diagnosis of microstructure, hardness, and the tool

condition is probably feasible, but it would require the application of a diagnostic strategy based on the integration of numerous measures,

e.g. using neural networks.

The work presents the test result of the influence of cooling rate on the microstructure of AZ91 alloy, Vickers micro-hardness and Brinell

hardness. Studies cooling and crystallization of AZ91 alloy was cast into the ceramic shells pre-heated to 180 ° C and then air-cooled at

ambient temperature or intensively super cooled in the liquid coolant. The TDA method was applied to record and characterize the thermal

effect resulting from the phase transformations occurring during the crystallization of AZ91 alloy. The kinetics and dynamics of the

thermal processes of crystallization of AZ91 alloy in the ceramic shells were determined. Metallographic tests were performed with the

use of an optical microscope. A comparison of these test results with the thermal effect recorded by way of the TDA method was made.

Influence of cooling rate of AZ91 on HV0, 01 micro-hardness and Brinell hardness alloy was examined.

The mathematical and numerical simulation model of the liquid steel flow in a tundish is presented in this paper. The problem was treated

as a complex and solved by the finite element method. The single-strand slab tundish is used to continuous casting slabs. The internal work

space of the tundish was modified by the following flow control devices. The first device was a striker pad situated in the pouring tundish

zone. The second device was a baffle with three holes and the third device was a baffle without hole. The main purpose of using these

devices was to cause a quiet liquid mixing as well as give directional metal flow upwards which facilitated inclusion floatation. The

interaction of flow control devices on hydrodynamic conditions was received from numerical simulation. As a result of the computations

carried out, the liquid steel flow and steel temperature fields were obtained. The influence of the tundish modification on velocity fields in

the liquid phase of steel was estimated, because these have an essential influence on high quality of a continuous steel cast slab.

The paper presents the results of simulation of alloy layer formation process on the model casting. The first aim of this study was to

determine the influence of the location of the heat center on alloy layer’s thickness with the use of computer simulation. The second aim of

this study was to predict the thickness of the layer. For changes of technological parameters, the distribution of temperature in the model

casting and temperature changes in the characteristic points of the casting were found for established changes of technological

parameters. Numerical calculations were performed using programs NovaFlow&Solid. The process of obtaining the alloy layer with good

quality and proper thickness depends on: pouring temperature, time of premould hold at the temperature above 1300o

C. The obtained

results of simulation were loaded to authorial program Preforma 1.1 in order to determine the predicted thickness of the alloy casting

This paper presents the effect of the temperature and hold time in the holding furnace of 226 silumin on the characteristic quantities of

TDA curves. The temperature of phase transformations and the cooling rate were tested.It has been shown that increasing both the hold

time and the temperature in the holdingfurnace cause the decreasethe end ofα+Al9Fe3Si2+β and α+Al2Cu+βternary eutectics

crystallizationtemperature in the tested silumin. This is due to the fact an increase in amounts of impurities as a result of reacting theliquid

alloy with the gases contained in the air.It has been shown, however, that examined technological factors ofthe metal preparation do not

cause systematic changes in the cooling rate.