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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 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 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 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.
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 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.
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 3-6m 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.
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.
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.
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.
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.