The measurement results concerning the abrasive wear of AlSi11-SiC particles composites are presented in paper. The method of
preparing a composite slurry composed of AlSi11 alloy matrix and 10, 20% vol.% of SiC particles, as well as the method of its highpressure
die casting was described. Composite slurry was injected into metal mould of cold chamber pressure die cast machine and
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. Very good uniform arrangement of SiC particles in volume composite matrix was observed and these
results were publicated early in this journal. The kinetics of abrasive wear and correlation with SiC particles arrangement in composite
matrix were presented. Better wear resistance of composite was observed in comparison with aluminium alloy. Very strong linear
correlation between abrasive wear and particle arrangement was observed. The conclusion gives the analysis and the interpretation of the
obtained results.
The present work studies the tribological properties of new hybrid material composed from high porosity open cell aluminum alloy (AlSi10Mg) skeleton and B83 babbitt infiltrated into it. The porous skeleton is obtained by replication method applying salt (NaCl) as space holder. The reinforcing phase of the skeleton consists of Al2O3 particles. The skeleton contains Al2O3 particles as reinforcement. The microstructure of the obtained materials is observed and the tribological properties are determined. A comparison between tribological properties of nominally nonporous aluminum alloy, high porosity open cell skeleton, babbitt alloy and the hybrid material is presented. It is concluded that new hybrid material has high wear resistivity and is a promising material for sliding bearings and other machine elements with high wear resistivity.
Among the copper based alloys, Cu-Al-X bronzes are commonly used as mold materials due to their superior physical and chemical properties. Mold materials suffer from both wear and corrosion, thus, it is necessary to know which one of the competitive phenomenon is dominant during the service conditions. In this study, tribo-corrosion behavior of CuAl10Ni5Fe4 and CuAl14Fe4Mn2Co alloys were studied and electrochemical measurements were carried out using three electrode system in 3.5 % NaCl solution in order to evaluate their corrosion resistance. In tribo-corrosion tests, alloys were tested against zirconia ball in 3.5 % NaCl solution, under 10N load with 0.04 m/s sliding speed during 300 and 600 m. The results indicate that (i) CuAl10Ni5Fe4 alloy is more resistant to NaCl solution compared to CuAl14Fe4Mn2Co alloy that has major galvanic cells within its matrix, (ii) although CuAl10Ni5Fe4 alloy has lower coefficient of friction value, it suffers from wear under dry sliding conditions, (iii) as the sliding distance increases, corrosion products on CuAl14Fe4Mn2Co surface increase at a higher rate compared to CuAl10Ni5Fe4 leading to a decrease in volume loss due to the lubricant effect of copper oxides.
This paper presents results of experimental research concerning the impact of an innovative method of micro-jet cooling on the padding
weld performed with MIG welding. Micro-jet cooling is a novel method patented in 2011. It enables to steer the parameters of weld
cooling in a precise manner. In addition, various elements which may e.g. enhance hardness or alter tribological properties can be entered
into its top surface, depending on the applied cooling gas. The material under study was steel 20MnCr5, which was subject to the welding
process with micro-jet cooling and without cooling. Nitrogen was used as a cooling gas. The main parameter of weld assessment was wear
intensity. The tests were conducted in a tribological pin-on-disc type position. The following results exhibit growth at approximately 5% in
wear resistance of padding welds with micro-jet cooling.
The article presents the investigation results of the crystallization (performed by means of the TDA method) and the microstructure of complex aluminium bronzes with the content of 6% Al, 4% Fe and 4% Ni, as well as Si additions in the scope of 1–2% and Cr additions in the scope of 0.1–0.3%, which have not been simultaneously applied before. For the examined bronze, the following tests were performed: hardness HB, impact strength (KU2). For bronze CuAl6Fe4Ni4Si2Cr0.3, characterizing in the highest hardness, wear tests were conducted with dry friction and the dry friction coefficient. The investigations carried out by means of the X-ray phase analysis demonstrated the following phases in the microstructure of this bronze: αCu, γ2 and complex intermetallic phases based on iron silicide type Fe3Si (M3Si M={Fe,Cr,…}). Compared to the normalized aluminium bronzes (μ=0.18–0.23), the examined bronze characterizes in relatively low wear and lower friction coefficient during dry friction (μ=0.147±0.016).
The paper presents tribological properties of A390.0 (AlSi17Cu5Mg) alloy coupled in abrasive action with EN-GJL-350 grey cast-iron.
The silumin was prepared with the use of two different technologies which differed in terms of cooling speed. In the first case the alloy
was modified with foundry alloy CuP10 and cast to a standard tester ATD and in case of second option the modified alloy was cast into
steel casting die. Due to different speed of heat removal the silumins varied in structure, particularly with size of primary crystals of silicon
and their distribution in matrix which had a significant influence of friction coefficient in conditions of dry friction.
Nowadays, Aluminium (Al) based hybrid surface composites are amongst the fastest developing advanced materials used for structural applications. Friction Stir Processing (FSP) has emerged as a clean and flexible solid-state surface composites fabrication technique. Intensive research in this field resulted in numerous research output; which hinders in finding relevant meta-data for further research with objectivity. In order to facilitate this research need, present article summarizes current state of the art and advances in aluminium based hybrid surface composites fabrication by FSP with in-situ and ex-situ approach. Reported literature were read and systematically categorized to show impacts of different types of reinforcements, deposition techniques, hybrid reinforcement ratio and FSP machine parameters on microstructures, mechanical and tribological characteristics of different Al alloys. Challenges and opportunities in this field have been summarized at the end, which will be beneficial to researchers working on solid state FSP technique.
In this study, AZ91 Magnesium alloy is produced by cold chamber high pressure die casting (HPDC) method. Different combinations of the cold chamber HPDC process parameters were selected as; in-mold pressure values of 1000 bar and 1200 bar, the gate speed of 30 m/s and 45 m/s, the casting temperatures of 640°C and 680°C. In addition, the test samples were produced by conventional casting method. Tensile test, hardness test, dry sliding wear test and microstructure analysis of samples were performed. The mechanical properties of the samples produced by the cold chamber HPDC and the conventional casting method were compared. Using these parameters; the casting temperature 680°C, in-mold pressure 1000 bar and the gate speed 30 m/s, the highest tensile strength and the hardness value were obtained. Since the cooling rate in the conventional casting method is slower than that of the cold chamber HPDC method, high mechanical properties are obtained by the formation of a fine-grained structure in the cold chamber HPDC method. In dry sliding wear tests, it was observed that there was a decrease in friction coefficient and less material loss with the increase of hardness values of the sample produced by the cold chamber HPDC method.