Wear resistance of TiC-cast steel metal matrix composite has been investigated. Composites were obtained with SHSB method known as
SHS synthesis during casting. It has been shown the differences in wear between composite and base cast steel. The Miller slurry
machine test were used to determine wear loss of the specimens. The slurry was composed of SiC and water. The worn surface of
specimens after test, were studied by SEM. Experimental observation has shown that surface of composite zone is not homogenous and
consist the matrix lakes. Microscopic observations revealed the long grooves with SiC particles indented in the base alloy area, and
spalling pits in the composite area. Due to the presence of TiC carbides on composite layer, specimens with TiC reinforced cast steel
exhibited higher abrasion resistance. The wear of TiC reinforced cast steel mechanism was initially by wearing of soft matrix and in
second stage by polishing and spalling of TiC. Summary weight loss after 16hr test was 0,14÷0,23 g for composite specimens and 0,90 g
for base steel
The work presents the investigation results concerning the structure of composite pressure die castings with AlSi11 alloy matrix reinforced
with SiC particles. Examination has been held for composites containing 10 and 20 volume percent of SiC particles. The arrangement of
the reinforcing particles within the matrix has been qualitatively assessed in specimens cut out of the castings. The index of distribution
was determined on the basis of particle count in elementary measuring fields. The tensile strength, the yield point and elongation of the
obtained composite were measured. Composite 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. The regression equation describing the change of
the considered arrangement particles index and mechanical properties were found as a function of the pressure die casting parameters. The
infuence of particle arrangement in composite matrix on mechanical properties these material was examined and the functions of
correlations between values were obtained. The conclusion gives the analysis and the interpretation of the obtained results.
The presented work describes the results of examination of the mechanical properties of castings made either of AlSi9Mg alloy matrix
composite reinforced with short carbon fibre or of the pure AlSi9Mg alloy. The tensile strength, the yield strength, Young’s modulus, and
the unit elongation were examined both for initial castings and for castings made of the remelted composite or AlSi9Mg alloy. After
preparing metallographic specimens, the structure of the remelted materials was assessed. A few non-metallic inclusions were observed in
the structure of the remelted composite, not occurring in the initial castings. Mechanical testing revealed that all the examined properties of
the initial composite material exceed those of the non-reinforced matrix. A decrease in mechanical properties was stated both for the metal
matrix and for the composite after the remelting process, but this decrease was so slight that it either does not preclude them from further
use or does not restrict the range of their application.
AM50/Mg2Si composites containing 5.7 wt. % and 9.9 wt. %. of Mg2Si reinforcing phase were prepared successfully by casting method. The microstructure of the cast AM50/Mg2Si magnesium matrix composites was investigated by light microscopy and X-ray diffractometry (XRD). The microstructure of these composites was characterized by the presence of α-phase (a solid solution of aluminium in magnesium), Mg17Al12 (γ-phase), Al8Mn5 and Mg2Si. It was demonstrated that the Mg2Si phase was formed mainly as primary dendrites and eutectic.
Copper have always been an important material and incorporation of elements into copper for property enhancement. Bronze is a relevant cuprous alloy which is important for many industrial and automotive applications like bearings and machineries. The present research is directed towards the fabrication and tribological analysis of regular bronze (Cu-6Sn) and metal matrix composites reinforced with varying particle sized SiC ceramic reinforcement (30, 35 and 40 μm). The developed specimens were subjected to wear analysis according to ASTM standards, to identify the tribological properties utilizing a pin on disk tribometer. It was noted that the wear rates of developed MMC’s phenomenally decremented with an increase in size of SiC particle reinforcement. Also, the test parameters were influential in altering the wear rates to notable margins. The standard scanning electron microscopy techniques aided in identifying the influence of adhesive wear on the specimen surface.
This paper presents the results of studies concerning the production and characterization of Al-SiC/W and Cu-SiC/W composite materials with a 30% volume fraction of reinforcing phase particles as well as the influence of corrosion and thermal shocks on the properties of selected metal matrix composites. Spark plasma sintering method (SPS) was applied for the purpose of producing these materials. In order to avoid the decomposition of SiC surface, SiC powder was coated with a thin tungsten layer using plasma vapour deposition (PVD) method. The obtained results were analysed by the effect of the corrosion and thermal shocks on materials density, hardness, bending strength, tribological and thermal properties. Qualitative X-ray analysis and observation of microstructure of sample surfaces after corrosion tests and thermal shocks were also conducted. The use of PVD technique allows us to obtain an evenly distributed layer of titanium with a constant thickness of 1.5 µm. It was found that adverse environmental conditions and increased temperature result in a change in the material behaviour in wear tests.
Metal matrix composites (MMC) are finding application in many fields such as aerospace and automobile industries. This is due to their advantages such as light weight and low cost. Among all the available non-traditional machining processes, wire electric discharge machining (WEDM) is found to be a suitable method for producing complex or intricate shapes in composite materials. In this study, an aluminum metal matrix composite (AMMC) with 6% and 8% weight (wt) fraction of Al2O3 is prepared through the stir casting process. The fabricated AMMC specimen is machined using WEDM, considering various process parameters such as wt % of reinforcement, gap voltage (Vg), peak current (IP) wire tension (WT) and dielectric pressure (Pd). Output responses such as the machining rate (MR) and surface roughness (Ra) of the slots are analyzed by conducting L18 mixed orthogonal array (OA) experiments. The experiments are analyzed using techniques for order preference by similarity to ideal solution (TOPSIS) and analysis of variance (ANOVA). Based on the analyses, the optimum combination of process parameters for better MR and Ra is as follows: wt % = 6 gm, Vg = 53 V, Ip = 8 A, WT = 11 g, Pd = 13 bar. The optimum level of process parameters for MR and Ra are 1.5 mm/min and 3.648 µm, respectively. Based on ANOVA, the peak current is found to have a significant influence on MR and Ra. Moreover, based on a scanning electron microscope (SEM) image, the presence of micro-ridges, reinforcement, micro-craters, micro-cracks, recast layers and oxide formation are all analyzed on the surface being machined.
The influence of boron carbide and tungsten carbide on the apparent porosity, density, coercive force, hardness and microstructure of metal matrix composite of the Ferro-TiC type, is presented in this paper. The samples of investigated steel/titanium carbide composite were produced by powder metallurgy process, i.e. by powders mixing and compacting followed by sintering in the vacuum furnace. According to the results, steel/titanium carbide composite materials with addition up to 11.9 vol.% of boron carbide are interesting to detailed investigation as well as materials having more than 17.2 vol.% of tungsten carbide because these compositions show significant changes in hardness and coercive force values.