The paper concerns modeling the microstructure of a hypereutectic aluminum-silicon alloy developed by the authors with the purpose of application for automobile cylinder liners showing high resistance to abrasive wear at least equal to that of cast-iron liners. With the use of the nanoindentation method, material properties of intermetallic phases and matrix in a hypereutectic Al-Si alloy containing Mn, Cu, Cr, Ni, V, Fe, and Mg as additives were examined. The scanning electron microscope equipped with an adapter for chemical composition microanalysis was used to determine the chemical composition of intermetallics and of the alloy matrix. Intermetallic phases, such as Al(Fe,Mn,M)Si, Al(Cr,V,M)Si, AlFeSi, AlFeNiM, AlCuNi, Al₂Cu, and Mg₂Si, including those supersaturated with various alloying elements (M), were identified based on results of X-ray diffraction (XRD) tests and microanalysis of chemical composition carried out with the use of X-ray energy dispersive spectroscopy (EDS). Shapes of the phases included regular, irregular, or elongated polygons. On the disclosed intermetallic phases, silicon precipitations, the matrix, values of the indentation hardness (H_IT), and the indentation modulus (E_IT) were determined by performing nanoindentation tests with the use of a Nanoindentation Tester NHT (CSM Instruments) equipped with a Berkovich B-L 32 diamond indenter. The adopted maximum load value was 20 mN.

The research reported in the paper concerned the conditions of cooling high-chromium cast iron with about 15% Cr content capable to ensure completeness of transformation of supercooled austenite into martensite in order to obtain high hardness value of the material and thus its high resistance to abrasive wear. For testing, castings were prepared with dimensions 120 mm × 100 mm × 15 mm cast in sand molds in which one of cavity surfaces was reproduced with chills. From the castings, specimens for dilatometric tests were taken with dimensions 4 mm × 4 mm × 16 mm and plates with dimensions 50 mm × 50 mm × 15 mm for heat treatment tests. The dilatometric specimens were cut out from areas subject to interaction with the chill. The austenitizing temperature and time were 1000 °C and 30 min, respectively. Dilatograms of specimens quenched in liquid nitrogen were used to determine martensite transformation start and finish temperatures T_Ms and T_Mf, whereas from dilatograms of specimens quenched in air and in water, only T_Ms was red out. To secure completeness of the course of transformation of supercooled austenite into martensite and reveal the transformation finish temperature, it was necessary to continue cooling of specimens in liquid nitrogen. It has been found that T_Ms depended strongly on the quenching method whereas T_Mf values were similar for each of the adopted cooling conditions. The examined cooling variants were used to develop a heat treatment process allowing to obtain hardness of 68 HRC.

The influence of heat treatment parameters such as the annealing time and austempering temperature on the microstructure, tribological properties and corrosion resistance of ductile iron have been investigated. It has been revealed that the scratch depth of cast iron samples increases with the extension of the isothermal annealing time (from 30 to 120 min) and the austempering temperature (from 280 °C to 430 °C), while the hardness value decreases. A low value of the scratch depth and a high hardness at low values of the austempering temperature and short isothermal annealing time is related to the presence of martensite. Moreover, the presence of a martensite phase has a beneficial influence on the corrosion resistance of austempered ductile iron.

This article presents the results of a study on the distribution of weld distortion in thin-walled components made of 17-4 PH steel, resulting from TIG (Tungsten Inert Gas) welding. Both manual and automatic welding processes were examined. Physical simulation of the automated welding process was conducted on a custom-built welding fixture. Analysis of weld distortion in thin-walled components made of 17-4 PH steel was based on the results of measurements of transverse shrinkage and displacement angle values. These measurements were taken on thin-walled parts before and after the welding process using a coordinate measuring machine (CMM). To determine the effect of manual and automated welding processes on the microstructure of the welded joint area, metallographic tests and hardness measurements were performed. The microstructure was analyzed using a scanning electron microscope (SEM). An analysis of the chemical composition of selected welded joint zones was also conducted. These tests were performed using an optical emission spectrometer (OES). According to the results, the use of automated welding and special fixtures for manufacturing thin-walled aircraft engine components made of 17-4 PH steel reduces the propensity of these components for distortion due to the effects of the thermal cycle of the welding process. This conclusion is supported by the results of the observation of the microstructure and analysis of the chemical composition of the various zones of the welded joint area.

The scratch test enables assessing the susceptibility of a material to the development of scratches and, being in some ways a measure of its abrasion resistance, allows extended knowledge in the field of material application usability, especially its machining capabilities. The aim of the study was to assess the resistance of a centrifugally formed AlSi12/SiC_p composite layer with a high share of reinforcing phase (V_p > 40%) to scratching with a diamond indenter. The microstructure and effect of the load applied to the diamond indenter on the scratch depth and susceptibility of the composite layer to the nucleation and propagation of cracks in hard and brittle SiC particles were analyzed. A simple model of SiC_p cracking depending on their size, shape (geometry), and orientation in relation to the direction of scratching has been proposed.