Investigations were carried out to ensure the granulated blast furnace (GBF) slag as an alternative mould material in foundry industry by
assessing the cast products structure property correlations. Sodium silicate-CO2 process was adopted for preparing the moulds. Three
types of moulds were made with slag, silica sand individually and combination of these two with 10% sodium silicate and 20 seconds CO2
gassing time. A356 alloy castings were performed on these newly developed slag moulds. The cast products were investigated for its
metallography and mechanical properties. Results reveal that cast products with good surface finish and without any defects were
produced. Faster heat transfers in slag moulds enabled the cast products with fine and refined grain structured; and also, lower Secondary
Dendrite Arm Spacing (SDAS) values were observed than sand mould. Slag mould casting shows improved mechanical properties like
hardness, compression, tensile and impact strength compared to sand mould castings. Two types of tensile fracture modes, namely
cleavage pattern with flat surfaces representing Al−Si eutectic zone and the areas of broken Fe-rich intermetallic compounds which appear
as flower-like morphology was observed in sand mould castings. In contrast, GBF slag mould castings exhibit majority in dimple fracture
morphology with traces of cleavage fracture. Charpy impact fractured surfaces of sand mould castings shows both transgranular and
intergranular fracture modes. Only intergranular fracture mode was noticed in both GBF slag and mixed mould castings.
Metal casting process involves processes such as pattern making, moulding and melting etc. Casting defects occur due to combination of
various processes even though efforts are taken to control them. The first step in the defect analysis is to identify the major casting defect
among the many casting defects. Then the analysis is to be made to find the root cause of the particular defect. Moreover, it is especially
difficult to identify the root causes of the defect. Therefore, a systematic method is required to identify the root cause of the defect among
possible causes, consequently specific remedial measures have to be implemented to control them. This paper presents a systematic
procedure to identify the root cause of shrinkage defect in an automobile body casting (SG 500/7) and control it by the application of
Pareto chart and Ishikawa diagram. with quantitative Weightage. It was found that the root causes were larger volume section in the cope,
insufficient feeding of riser and insufficient poured metal in the riser. The necessary remedial measures were taken and castings were
reproduced. The shrinkage defect in the castings was completely eliminated.
The results of investigations of the rheological properties of typical ceramic slurries used in the investment casting technology – the lost
wax technology are presented in the paper. Flow curves in the wide range of shear velocity were made. Moreover, viscosity of ceramic
slurries depending on shearing stresses was specified. Tests were performed under conditions of three different temperatures 25, 30 and
35oC, which are typical and important in the viewpoint of making ceramic slurries in the investment casting technology.
In the light of the performed investigations can be said that the belonging in group of Newtonian or Non – Newtonian fluid is dependent
on content of solid phase (addition of aluminum oxide) in the whole composition of liquid ceramic slurries.
Cast stainless steel of the Cr-Ni duplex type is used, among others, for the cast parts of pumps and valves handling various chemically
aggressive media. Therefore, the main problem discussed in this article is the problem of abrasion wear resistance in a mixture of SiC and
water and resistance to electrochemical corrosion in a 3% NaCl- H2O solution of selected cast steel grades, i.e. typical duplex cast steel,
high silicon and manganese duplex cast steel, and Cr-Ni austenitic cast steel (type AISI 316L). The study shows that the best abrasion
wear resistance comparable to Ni-Hart cast iron was obtained in the cast duplex steel, where Ni was partially replaced with Mn and N.
This cast steel was also characterized by the highest hardness and matrix microhardness among all the tested cast steel grades. The best
resistance to electrochemical corrosion in 3% NaCl- H2O solution showed the cast duplex steel with high content of Cr, Mo and N. The
addition of Ni plays rather insignificant role in the improvement of corrosion resistance of the materials tested.
It is well-known that the better the control of the liquid aluminium allows obtaining of better properties. One of the most important defects
that is held responsible for lower properties has been the presence of porosity. Porosity has always been associated with the amount of
dissolved hydrogen in the liquid. However, it was shown that hydrogen was not the major source but only a contributor the porosity. The
most important defect that causes porosity is the presence of bifilms. These defects are surface entrained mainly due to turbulence and
uncontrolled melt transfer. In this work, a cylindrical mould was designed (Ø30 x 300 mm) both from sand and die. Moulds were produced
both from sand and die. Water cooled copper chill was placed at the bottom of the mould in order to generate a directional solidification.
After the melt was prepared, prior to casting of the DC cast samples, reduced pressure test sample was taken to measure the melt quality
(i.e. bifilm index). The cast parts were then sectioned into regions and longitudinal and transverse areas were investigated
metallographically. Pore size, shape and distribution was measured by image analysis. The formation of porosity was evaluated by means
of bifilm content, size and distribution in A356 alloy.
This paper presents the results of hypoeutectic 226 grade alloy as well as prepared on its basis Al-Si alloy containing Cr, V and Mo. The
additives tested were added as AlCr15, AlV10 and AlMo8 master alloys. Alloys tested were poured into DTA sampler as well as using
pressure die casting. An amount of Cr, V and Mo additives in alloy poured into DTA sampler comprised within the range approximately
0.05-0.35%. Alloys to pressure die casting contained 0.05-0.20% Cr, V and Mo. The crystallization process was examined using the derivative
thermal analysis (DTA). The microstructure of castings made in the DTA sampler as well as castings made with use of pressure die
casting were examined. The basic mechanical properties of castings made using pressure die casting were defined too. It has been shown
in the DTA curves of Al-Si alloy containing approximately 0.30 and 0.35% Cr, Mo, and V there is an additional thermal effect probably
caused by a peritectic crystallization of intermetallic phases containing the aforementioned additives. These phases have a morphology
similar to the walled and a relatively large size. The analogous phases also occur in pressure die casting alloys containing 0.10% or more
additions of Cr, V and Mo. The appearance of these phases in pressure die casting Al-Si alloys coincides with a decrease in the value of
the tensile strength Rm and the elongation A. It has been shown die castings made of Al-Si alloys containing the aforementioned additives
have a higher Rm and A than 226 alloy.
The paper presents the production problems related to casting using precision casting methods. The essential adverse effect of the casting
process is the presence of burrs understood as oversize material necessary to remove the next finishing operations. In addition, the surfaces
of the cast often characterized by a porous structure. One of the methods to improve the smoothness of the area proposed by the authors is
the use of vibro-abrasive finishing. This type of treatment is widely used in the treatment of finishing small objects as well as complex
shapes. Objects in the form of casting in the first step was treated with aggressive deburring polyester matrix abrasive media. The second
stage was polishing, with using smoothing porcelain media. The study evaluated the effect of vibro-abrasive machining typical cast on the
basic parameters of the geometric structure of the surface. Observations using optical microscope Nicon Eclipse MA 200 compared
changes in surface microstructure and the effect of deburring. Clearly we can say that vibro-abrasive machining an effective way
of reducing the size of burrs, smoothing and lightening the surface of objects made by casting.
The paper presents the possibility of application of the developed computer script which allows the assessment of non-equilibrium
solidification of binary alloys in the ThermoCalc program. The script makes use of databases and calculation procedures of the POLY-3
module. A solidification model including diffusion in the solid state, developed by Wołczyński, is used to describe the non-equilibrium
solidification. The model takes into account the influence of the degree of solute segregation on the solidification process by applying the
so-called back-diffusion parameter. The core of the script is the iteration procedure with implemented model equation. The possibility of
application of the presented calculation method is illustrated on the example of the Cr-30% Ni alloy. Computer simulations carried out
with use of the developed script allow to determine the influence of the back-diffusion parameter on the course of solidification curves,
solidus temperature, phase composition of the alloy and the fraction of each phase after the solidification completion, the profile of solute
concentration in liquid during solidification process, the average solute concentration in solid phase at the eutectic temperature and many
other quantities which are usually calculated in the ThermoCalc program.
The paper presents an analysis of the effect of shape of primary silicon crystals on the sizes of stresses and deformations in a surface layer
of A390.0 alloy by Finite Elements Method (FEM). Analysis of stereological characteristics of the studied alloy, performed based on a
quantitative metallographic analysis in combination with a statistical analysis, was used for this purpose. The presented simulation tests
showed not only the deposition depth of maximum stresses and strains, but also allowed for determining the aforementioned values
depending on the shape of the silicon crystals. The studied material is intended for pistons of internal combustion engines, therefore the
analysis of the surface layer corresponded to conditions during friction in a piston-cylinder system of an internal combustion engine having
power of up to 100 kW. The obtained results showed important differences in the values of stresses and strains up to 15% between various
shape of the silicon crystals. Crystals with sharp edges caused higher stresses and deformation locally than those with rounded shapes.
In order for the working status of the aluminum alloyed hydraulic valve body to be controlled in actual conditions, a new friction and wear
design device was designed for the cast iron and aluminum alloyed valve bodies comparison under the same conditions. The results
displayed that: (1) The oil leakage of the aluminum alloyed hydraulic valve body was higher than the corresponding oil leakage of the iron
body during the initial running stage. Besides during a later running stage, the oil leakage of the aluminum alloyed body was lower than
corresponding oil leakage of the iron body; (2) The actual oil leakage of different materials consisted of two parts: the foundation leakage
that was the leakage of the valve without wear and wear leakage that was caused by the worn valve body; (3) The aluminum alloyed valve
could rely on the dust filling furrow and melting mechanism that led the body surface to retain dynamic balance, resulting in the valve
leakage preservation at a low level. The aluminum alloy modified valve body can meet the requirements of hydraulic leakage under
pressure, possibly constituting this alloy suitable for hydraulic valve body manufacturing.
This paper discusses the joining of AZ91 magnesium alloy with AlSi17 aluminium alloy by compound casting. Molten AZ91 was cast at
650oC onto a solid AlSi17 insert placed in a steel mould under normal atmospheric conditions. Before casting, the mould with the insert
inside was heated up to about 370oC. The bonding zone forming between the two alloys because of diffusion had a multiphase structure
and a thickness of about 200 µm. The microstructure and composition of the bonding zone were analysed using optical microscopy,
scanning electron microscopy and energy dispersive X-ray spectroscopy. The results indicate that the bonding zone adjacent to the AlSi17
alloy was composed of an Al3Mg2 intermetallic phase with not fully consumed primary Si particles, surrounded by a rim of an Mg2Si
intermetallic phase and fine Mg2Si particles. The bonding zone near the AZ91 alloy was composed of a eutectic (an Mg17Al12 intermetallic
phase and a solid solution of Al and Si in Mg). It was also found that the compound casting process slightly affected the AZ91alloy
microstructure; a thin layer adjacent to the bonding zone of the alloy was enriched with aluminium.
The article presents a study on the effectiveness of the foundries using Data Envelopment Analysis (DEA) method. The aim of the article
is to analyze the usefulness of DEA method in the study of the relative efficiency of the foundries. DEA is a benchmarking technique
based on linear programming to evaluate the effectiveness of the analyzed objects. The research was conducted in four Polish and two
foreign plants. Evaluated foundries work in similar markets and have similar production technology. We created a DEA model with two
inputs (fixed assets and employment) and one output (operating profit). The model was produced and solved using Microsoft Excel
together with its Solver add-in. Moreover, we wrote a short VBA script to perform automating calculations. The results of our study
include a benchmark and foundries’ ranking, and directions to improve the efficiency of inefficient units. Our research has shown that
DEA can be a very valuable method for evaluating the efficiency of foundries.
Defects affect the properties and behavior of the casting during its service life. Since the defects can occur due to different reasons, they
must be correctly identified and categorized, to enable applying the appropriate remedial measures. several different approaches for
categorizing casting defects have been proposed in technical literature. They mainly rely on physical description, location, and formation
of defects. There is a need for a systematic approach for classifying investment casting defects, considering appropriate attributes such as
their size, location, identification stage, inspection method, consistency, appearance of defects. A systematic approach for categorization of
investment casting defects considering multiple attributes: detection stage, size, shape, appearance, location, consistency and severity of
occurrence. Information about the relevant attributes of major defects encountered in investment casting process has been collected from
an industrial foundry. This has been implemented in a cloud-based system to make the system freely and widely accessible.
The nanocomposites based on water glass matrix were attempted in the study. Nanoparticles of ZnO, Al2O3 or MgO in organic solutions
were applied into water glass matrix in the amounts of: 1.5; 3; 4 or 5 mas. %. Wettability of the quartz sad by the nanocomposites based on
water glass matrix was determined by testing changes of the wetting angle θ in time τ for the system: quartz – binder in non-stationary
state, by means of the device for measuring wetting angles. Wettability measurements were carried out under isothermal conditions at an
ambient temperature (20 – 25 oC). The modification improves wettability of quartz matrix by water glass, which is effective in improving
strength properties of hardened moulding sands. Out of the considered modifiers in colloidal solution of propyl alcohol water glass
modified by MgO nanoparticles indicated the smallest values of the equilibrium wetting angle θr. This value was equal app. 11 degrees and
was smaller no less than 40 degrees than θr value determined for not modified water glass. Viscosity η of nanocomposites based on water
glass matrix was determined from the flow curve, it means from the empirically determined dependence of the shearing stress τ on shear
rate γ: τ = f (γ) (1), by means of the rotational rheometer. Measurements were carried out at a constant temperature of 20 oC. The
modification influences the binder viscosity. This influence is conditioned by: amount of the introduced modifier as well as dimensions and
kinds of nanoparticles and organic solvents. The viscosity increase of the modified binder does not negatively influence its functional
properties.
The results of researches of sorption processes of surface layers of components of sand moulds covered by protective coatings are
presented in the hereby paper. Investigations comprised various types of sand grains of moulding sands with furan resin: silica sand,
reclaimed sand and calcined in temperature of 700oC silica sand. Two kinds of alcoholic protective coatings were used – zirconium and
zirconium – graphite. Tests were performed under condition of a constant temperature within the range 30 – 35oC and high relative air
humidity 75 - 80%. To analyze the role of sand grains in sorption processes quantitavie moisture sorption with use of gravimetric method
and ultrasonic method were used in measurements. The tendency to moisture sorption of surface layers of sand moulds according to the
different kinds of sand grains was specified. The effectiveness of protective action of coatings from moisture sorption was analyzed as
well.
Knowledge of the role of sand grains from the viewpoint of capacity for moisture sorption is important due to the surface casting defects
occurrence. In particular, that are defects of a gaseous origin caused by too high moisture content of moulds, especially in surface layers.
The paper presents results of bend tests at elevated temperatures of aluminium alloy EN AC-44200 (AlSi12) based composite materials
reinforced with aluminium oxide particles. The examined materials were manufactured by squeeze casting. Preforms made of Al2O3
particles, with volumetric fraction 10, 20, 30 and 40 vol.% of particles joined with sodium silicate bridges were used as reinforcement. The
preforms were characterised by open porosity ensuring proper infiltration with the EN AC-44200 (AlSi12) liquid alloy. The largest
bending strength was found for the materials containing 40 vol.% of reinforcing ceramic particles, tested at ambient temperature. At
increased test temperature, bending strength Rg of composites decreased in average by 30 to 50 MPa per 100°C of temperature increase.
Temperature increase did not significantly affect cracking of the materials. Cracks propagated mainly along the interfaces particle/matrix,
with no effect of the particles falling-out from fracture surfaces. Direction of cracking can be affected by a small number of
agglomerations of particles or of non-reacted binder. In the composites, the particles strongly restrict plastic deformation of the alloy,
which leads to creation of brittle fractures. At elevated temperatures, however mainly at 200 and 300°C, larger numbers of broken,
fragmented particles was observed in the vicinity of cracks. Fragmentation of particles occurred mainly at tensioned side of the bended
specimens, in the materials with smaller fraction of Al2O3 reinforcement, i.e. 10 and 20 vol.%.
The work presents the results of examinations concerning the influence of various amounts of home scrap additions on the porosity of
castings made of MgAl9Zn1 alloy. The fraction of home scrap in the metal charge ranged from 0 to 100%. Castings were pressure cast by
means of the hot-chamber pressure die casting machine under the industrial conditions in one of the domestic foundries. Additionally, for
the purpose of comparison, the porosity of specimens cut out directly of the MgAl9Zn1 ingot alloy was also determined. The examinations
consisted in the qualitative assessment of porosity by means of the optical microscopy and its quantitative determination by the method of
weighting specimens in air and in water. It was found during the examination that the porosity of castings decreases with an increase in the
home scrap fraction in the metal charge. The qualitative examinations confirmed the beneficial influence of the increased home scrap
fraction on the porosity of castings. It was concluded that the reusing of home scrap in a foundry can be a good way of reduction of costs
related to the production of pressure castings.
Measurements of the hardening process of the selected self-setting sands are presented in the hereby paper. Moulding sands were prepared
on the matrix of „Szczakowa” sand of the Sibelco Company. Two resins: phenol-formaldehyde-furfuryl (FF/AF) and urea-formaldehydefurfuryl
(MF/AF) were used for making moulding sands. – Methylbenzene-sulphonic acid was applied as a hardener for the moulding sand
on FF/AF resin, while paratoluene-sulphonic acid for the moulding sand on MF/AF resin. Both hardeners were used in two concentrations:
low – the so-called ‘slow’ hardener and high - ‘fast’ hardener. During investigations, the courses of the hardening process were
determined, more accurately changes of the velocity of the ultrasound wave passage through the moulding sand cL = f(t) and changes of
the moulding sand hardening degree versus time, Sx = f(t). In addition, the kinetics of the hardening process was determined.
Measurements were performed on the research stand for ultrasound investigations.
The paper is focused on properties testing of materials used in form of iso-exo sleeves for risers in ferrous alloys foundry. They are grainyfibrous
materials, containing components which initiate and upkeep exothermic reaction. Thermo-physical parameters characterizing such
sleeves are necessary also to fill in reliable databases for computer simulation of processes in the casting-mould layout. Studies with use of
a liquid alloy, especially regarding different sleeves bring valuable results, but are also relatively expensive and require longer test
preparation time. A simplified method of study in laboratory conditions was proposed, in a furnace heated to a temperature above ignition
temperature of sleeve material (initiation of exothermic reaction). This method allows to determine the basic parameters of each new
sleeve supplied to foundries and assures relatively quick evaluation of sleeve quality, by comparison with previous sleeve supplies or with
sleeves brought by new providers.
This article presents data on the anthropogenic air emissions of selected substances (CO2, SO2, total suspended particles (TSP), dioxins
and furans (PCDD/F), Pb and Cd) subject to reporting under the Climate Convention (UNFCCC) or the Convention on Long-range
Transboundary Air Pollution (UNECE CLRTAP). It also presents the national emissions of these substances in 2014 by the major source
categories and defines the share of metal production in these emissions. Analysis is based on national emission inventory reports. Most
important source of air emission in case of CO2 and SO2 is 1.A.1 Energy industries category. TSP and PCDD/F are emitted mainly from
fuel combustion in small sources (i.a. households). Emission of heavy metals (Pb and Cd) is connected mostly with 1.A.2. Manufacturing
industries and construction category. Metallurgy is significant source of emission only for lead and cadmium from among all considered
substances. The shares of particular sectors in the national emissions of given pollutants are important, in view of the possible reduction
measures and the determination in which industries they could bring about tangible results.
Emission of gases under high temperature after pouring molten metal into moulds, which contain the organic binder or other additives
(solvents or curing agent), may be an important factor influencing both on the quality of the produced castings, and on the state of
environment. Therefore, a comprehensive study of the emitted gases would allow to determine restrictions on the use of the moulding
sands in foundry technologies, eg. the probability of occurrence of casting defects, and identify the gaseous pollutants emitted to the
environment. The aim of the research presented in this paper was to determine the amount of gases that are released at high temperatures
from moulding sands bonded by biopolymer binder and the quantitative assessment of the emitted pollutants with particular emphasis on
chemical compounds: benzene, toluene, ethylbenzene and xylenes (BTEX). The water-soluble modified potato starch as a sodium
carboxymethyl starch with low (CMS-NaL) or high (CMS-NaH) degree of substitution was a binder in the tested moulding sands.
A tests of gases emission level were conducted per the procedure developed at the Faculty of Foundry Engineering (AGH University of
Science and Technology) involving gas chromatography method (GC). The obtained results of the determination of amount of BTEX
compounds generated during the decomposition process of starch binders showed lower emission of aromatic hydrocarbons in comparison
with binder based on resin Kaltharz U404 with the acidic curing agent commonly used in the foundries.
The study presents the results of the investigations of the effect of Cu, Ni, Cr, V, Mo and W alloy additions on the microstructure and
mechanical properties of the AlSi7Mg0.3 alloy. The examinations were performed within a project the aim of which is to elaborate an
experimental and industrial technology of producing elements of machines and devices complex in their construction, made of aluminium
alloys by the method of precision investment casting. It was demonstrated that a proper combination of alloy additions causes the
crystallization of complex intermetallic phases in the silumin, shortens the SDAS and improves the strength properties: Rm, Rp0.2,HB
hardness. Elevating these properties reduces At, which, in consequence, lowers the quality index Q of the alloy of the obtained casts.
Experimental casts were made in ceramic moulds preliminarily heated to 160 °C, into which the AlSi7Mg0.3 alloy with the additions was
cast, followed by its cooling at ambient temperature. With the purpose of increasing the value of the quality index Q, it is recommended
that the process of alloy cooling in the ceramic mould be intensified and/or a thermal treatment of the casts be performed (ageing)(T6).
The study includes the results of research conducted on selected lead-free binary solder alloys designed for operation at high temperatures.
The results of qualitative and quantitative metallographic examinations of SnZn alloys with various Zn content are presented. The
quantitative microstructure analysis was carried out using a combinatorial method based on phase quanta theory, per which any
microstructure can be treated as an array of elements disposed in the matrix material. Fatigue tests were also performed using the
capabilities of a modified version of the LCF method hereinafter referred to in short as MLCF, which is particularly useful in the
estimation of mechanical parameters when there are difficulties in obtaining many samples normally required for the LCF test. The fatigue
life of alloys was analyzed in the context of their microstructure. It has been shown that the mechanical properties are improved with the
Zn content increasing in the alloy. However, the best properties were obtained in the alloy with a chemical composition close to the
eutectic system, when the Zn-rich precipitates showed the most preferred morphological characteristics. At higher content of Zn, a strong
structural notch was formed in the alloy because of the formation in the microstructure of a large amount of the needle-like Zn-rich
precipitates deteriorating the mechanical characteristics. Thus, the results obtained during previous own studies, which in the field of
mechanical testing were based on static tensile test only, have been confirmed. It is interesting to note that during fatigue testing, both
significant strengthening and weakening of the examined material can be expected. The results of fatigue tests performed on SnZn alloys
have proved that in this case the material was softened.
The article presents crystallization process of silicon molybdenum ductile cast iron (SiMo). The alloy with 5% silicon content and with
variable amounts of Mo in a range of 0-1% was chosen for the research. The carbon content in the analysed alloys did not exceed 3,1%.
The studies of crystallization process were based on thermal – derivative analysis (TDA). Chemical composition of all examined samples
was analysed with the use of LECO spectrometer. Additionally, the carbon and the sulphur content was determined basing on carbon and
sulphur LECO analyser. For metallographic examination, the scanning electron microscopy (SEM) with EDS analyser was used. Disclosed
phases have been also tested with the use of X-ray diffraction. The results allowed the description of crystallization processes of silicon
molybdenum ductile cast iron using thermal – derivative analysis (TDA). Conducted studies did not allow for the clear identification of all
complex phases containing molybdenum, occurring at the grain boundaries. Therefore, the further stages of the research could include the
use of a transmission electron microscope to specify the description of complex compounds present in the alloy.