The article presents the method to assess the diffusion coefficient D in the sub-layer of intermetallic phases formed during hot-dip

galvanizing “Armco” iron and ductile cast iron EN-GJS-500-7. Hot-dip galvanizing is one of the most popular forms of long-term

protection of Fe-C alloys against corrosion. The process for producing a protective layer of sufficient quality is closely related to diffusion

of atoms of zinc and iron. The simulation consist in performed a hot-dip galvanizing in laboratory condition above Fe-C alloys, in the

Department of Engineering of Cast Alloys and Composites. Galvanizing time ranged from 15 to 300 seconds. Then metallographic

specimens were prepared, intermetallic layers were measured and diffusion coefficient (D) were calculated. It was found that the diffusion

coefficient obtained during hot-dip galvanizing “Armco” iron and zinc is about two orders of magnitude less than the coefficient obtained

on ductile cast iron EN-GJS-500-7.

In this paper the effect of soldering technique and thermal shock test were investigated on SAC 305 solder joints, produced by two different solder method. The solder joints were subjected to different cycle numbers up to 5000 thermal shock tests with two different thermal profiles of –30/+110°C and –40/+125°C. Microstructural properties of the tested joints were examined with the focus on intermetallic layer thickness and crack formation/propagation. Thickness of the scallop shaped Cu6Sn5 intermetallic layer was increased with increasing cycle number for both THRS and multiwave joints, but the thickening was more effective for the THRS joints. Cracks typically formed at the solder alloy/ PTH barrel and the solder alloy/pin interfaces and propagated along grain boundaries and precipitations of intermetallic compound.

In the past few years, overhead copper transmission lines have been replaced by lightweight aluminum transmission lines to minimize the cost and prevent the sagging of heavier copper transmission lines. High strength aluminum alloys are used as the core of the overhead transmission lines because of the low strength of the conductor line. However, alloying copper with aluminum causes a reduction in electrical conductivity due to the solid solution of each component. Therefore, in this study, the authors attempt to study the effect of various Al/Cu ratios (9:1, 7:3, 5:5) to obtain a high strength Al-Cu alloy without a significant loss in its conductivity through powder metallurgy. Low-temperature extrusion of Al/Cu powder was done at 350ºC to minimize the alloying reactions. The as-extruded microstructure was analyzed and various phases (Cu9Al4, CuAl2) were determined. The tensile strength and electrical conductivity of different mixing ratios of Al and Cu powders were studied. The results suggest that the tensile strength of samples is improved considerably while the conductivity falls slightly but lies within the limits of applications.

The research described in this contribution is focused on fractographic analysis of the fracture area of newly developed eutectic silumin type AlSi9NiCuMg0.5 (AA 4032), which was developed and patented by a team of staff of the Faculty of Mechanical Engineering. The paper presents determination of the cause of casting cracks in operating conditions. Fractographic analysis of the fracture area, identification of the structure of the casting, identification of structural components on the surface of the fracture surface and chemical analysis of the material in the area of refraction were performed within the experiment. Al-Si alloys with high specific strength, low density, and good castability are widely used in pressure-molded components for the automotive and aerospace industries. The results shown that the inter-media phases Fe-Al and Fe-Si in aluminium alloys lead to breakage across the entire casting section and a crack that crossed the entire cross section, which was confirmed by EDS analysis.

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.

Al- and Al/Zn-enriched layers containing intermetallic phases were deposited on the Mg substrate by heating the Mg specimens in contact with the powdered materials in a vacuum furnace. The Al-enriched surface layers were produced using Al powder, whereas the Al/Znenriched layers were obtained from an 80 wt.% Al + 20 wt.% Zn powder mixture. The microstructure and composition of the layers were analyzed by optical microscopy, scanning electron microscopy and X-ray diffraction. The results showed that the Al-enriched layer comprised an Mg17Al12 intermetallic phase and a solid solution of Al in Mg. The layer obtained from the Al+Zn powder mixture was composed of Mg-Al-Zn intermetalic phases and a solid solution of Al and Zn in Mg. Adding 20% of Zn into the Al powder resulted in the formation of a considerably thicker layer. Moreover, the hardness of the surface layers was much higher than that of the Mg substrate.

The gas porosity is one of the most serious problems in the casting of aluminum. There are several degassing methods that have been

studied. During smelting of aluminum, the intermetallic compound (IMC) may be formed at the interface between molten aluminum and

solid steel of crucible furnace lining. In this study, the effect of degassing treatment on the formations of IMC has been investigated. The

rectangular substrate specimens were immersed in a molten aluminum bath. The holding times of the substrate immersions were in the

range from 300 s to 1500 s. Two degassing treatments, argon degassing and hexachloroethane tablet degassing, were conducted to

investigate their effect on the IMC formation. The IMC was examined under scanning electron microscope with EDX attachment. The

thickness of the IMC layer increased with increasing immersion time for all treatments. Due to the high content of hydrogen, substrate

specimens immersed in molten aluminum without degasser had IMC layer which was thicker than others. Argon degassing treatment was

more effective than tablet degassing to reduce the IMC growth. Furthermore, the hard and brittle phase of IMC, FeAl3, was formed

dominantly in specimens immersed for 900 s without degasser while in argon and tablet degasser specimens, it was formed partially.

Operating conditions turbocharger (high temperature and corrosive environment) mean that the device is classified into one of the most elements of the emergency drive unit of the car. The failure rate can be reduced through the use of modern heat-resistant materials, which include based alloys FeAl intermetallic phase. Intermetallic alloys belong to the group of materials known as prospective due to their advantageous properties, in particular their high specific strength, high melting point and good resistance to corrosion and oxidation at high temperatures. In the article presented results of the research axis roll control system variable geometry blades made of intermetallic alloy Fe40Al5Cr0,2TiB as a substitute so far made of austenitic steel. A verification service conditions, comparing the degradation of the material previously used by manufacturers of turbochargers for elements of the control system degradation axes made of intermetallic alloy Fe40Al5Cr0,2TiB. The study consisted of determining microstructure and corrosion products after use. Observations of the structure and the surface of the corrosion tests were performed using light microscopy, scanning electron microscopy and X-ray microanalysis EDS chemical composition.

The paper presents the results and provides an analyse of the geometric structure of Fe-Al protective coatings, gas-treated under specified GDS conditions. The analysis of the surface topography was conducted on the basis of the results obtained from the SEM data. Topographic images were converted to three-dimensional maps, scaling the registered amplitude coordinates of specific gray levels to the relative range of 0÷1. This allowed us to assess the degree of surface development by determining the fractal dimension. At the same time, the generated three-dimensional spectra of the autocorrelation function enabled the researchers to determine the autocorrelation length (Sal) and the degree of anisotropy (Str) of the surfaces, in accordance with ISO 25178. Furthermore, the reconstructed three-dimensional images of the topography allowed us to evaluate the functional properties o the studied surfaces based on the Abbott-Firestone curve (A-F), also known as the bearing area curve. The ordinate describing the height of the profile was replaced by the percentage of surface amplitude in this method, so in effect the shares of the height of the three-dimensional topographic map profiles of various load-bearing properties were determined. In this way, both the relative height of peaks, core and recesses as well as their percentages were subsequently established.

Al2Cu phase has been obtained by melting pure metals in the electric arc furnace. It has been found that the intermetallic phase undergoes selective corrosion in the H3PO4 aqueous solutions. Aluminium is dissolved, the surface becomes porous and enriched with copper. The corrosion rate equals to 371 ± 17 g·m–2·day–1 (aerated solution) and 284 ± 9 g·m–2·day–1 (deaerated solution). The surface of Al2Cu phase after selective corrosion was characterised by using electrochemical impedance spectroscopy. It was found that the surface area of the specimens increases with temperature due to higher corrosion rate and is between 2137 and 3896 cm2.

This paper aims to investigate the microstructural evolution and mechanical properties of hot-deformed AlMg4 alloys with Mn, Fe, and Si as the main impurities. For this purpose, solidification behavior and microstructural evolution during hot-rolling and heat-treatment processes are investigated by using theoretical calculations and experimental characterization. The crystallization and morphological transformation of intermetallic Al3Fe, Al6Mn, and Mg2Si phases are revealed and discussed in terms of the variation in chemical composition. Following a homogenization heat-treatment, the effect of heat treatment on the intermetallic compounds is also investigated after hot-rolling. It was revealed that the Mg2Si phase can be broken into small particles and spherodized more easily than the Al3Fe intermetallic phase during the hot-rolling process. For the Mn containing alloys, both yield and ultimate tensile strength of the hot-rolled alloys increased from 270 to 296 MPa while elongation decreased from 17 to 13%, which can be attributed to Mn-containing intermetallic as well as dispersoid.

Purpose: The influence of age-hardening solution treatment at temperature 515 degrees centigrade with holding time 4 hours, water quenching at 40 degrees centigrade and artificial aging by different temperature 130, 150, 170 and 210 degrees centigrade with different holding time 2, 4, 8, 16 and 32 hours on changes in morphology of Fe-rich Al15(FeMn)3Si2and Cu-rich (Al2Cu, Al-Al2Cu-Si) intermetallic phases in recycled AlSi9Cu3 cast alloy. Material/Methods: Recycled (secondary) AlSi9Cu3 cast alloy is used especially in automotive industry (dynamic exposed cast, engine parts, cylinder heads, pistons and so on). Microstructure was observed using a combination of different analytical techniques (scanning electron microscopy upon standard and deep etching and energy dispersive X-ray analysis – EDX) which have been used for the identification of the various phases. Quantitative study of changes in morphology of phases was carried out using Image Analyzer software NIS-Elements. The mechanical properties (Brinell hardness and tensile strength) were measured in line with STN EN ISO. Results/Conclusion: Age-hardening led to changes in microstructure include the spheroidization of eutectic silicon, gradual disintegration, shortening and thinning of Fe-rich intermetallic phases and Al-Al2Cu-Si phases were fragmented, dissolved and redistributed within alpha-matrix. These changes led to increase in the hardness and tensile strength in the alloy.

The study presents the results of research on the development of composite zones in castings based on the intermetallic phase of Ni3Al. Composite zones were obtained by placing packets with substrates for the reaction of titanium carbide in a foundry mould. To provide a variable carbides content in the composite zone, two compositions of the packets were prepared. The first packet contained only substrates for the reaction of TiC synthesis; the second one also contained a filler. The resulting composite zones in castings were examined for the filler effect on changes in the volume fraction, size and morphology of carbides in the zone. In addition, the effect of filler on the mechanical properties of the zone was verified, observing changes of Vickers hardness in this area. It was found that the presence of filler in the composition of the packet for synthesis reduced the content of carbides, as well as their size and morphology. Lower surface content of carbides reduced hardness of the zone, which enabled smooth control of the mechanical properties. At the same time, the use of the selected filler did not disturb the course of the TiC carbide synthesis.

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.

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.

Presence of iron in Al-Si cast alloys is common problem mainly in secondary (recycled) aluminium alloys. Better understanding of iron

influence in this kind of alloys can lead to reduction of final castings cost. Presented article deals with examination of detrimental iron

effect in AlSi10MgMn cast alloy. Microstructural analysis and ultimate tensile strength testing were used to consider influence of iron to

microstructure and mechanical properties of selected alloy

Al-enriched layer was formed on a magnesium substrate with use of casting. The magnesium melt was cast into a steel mould with an

aluminium insert placed inside. Different conditions of the casting process were applied. The reaction between the molten magnesium and

the aluminium piece during casting led to the formation of an Al-enriched surface layer on the magnesium substrate. The thickness of the

layer was dependent on the casting conditions. In all fabricated layers the following phases were detected: a solid solution of Mg in Al,

Al3Mg2, Mg17Al12 and a solid solution of Mg in Al. When the temperature of the melt and the mould was lower (variant 1 – 670o

C and 310 o

; variant 2 – 680o

C and 310o

C, respectively) the unreacted thin layer of aluminium was observed in the outer zone. Applying higher

temperatures of the melt (685o

C) and the mould (325o

C) resulted in deep penetration of aluminium into the magnesium substrate. Areas

enriched in aluminium were locally observed. The Al-enriched layers composed mainly of Mg-Al intermetallic phases have hardness from

187-256 HV0.1.