Formation of composites with an aluminum matrix reinforced with tungsten carbide nanoparticles

Abstract

Relevance. The fact that composites with a metal matrix and structural products based on them are in great demand in various industries, including the automotive industry, aerospace industry, and shipbuilding. Aluminum matrix composites are the most popular since they combine the excellent ductility, low density, good corrosion resistance of aluminum and the high strength, hardness and wear resistance of a ceramic reinforcing component. Aim. To obtain bulk Al-WC metal matrix composites with different contents of the reinforcing phase and with increased physical and mechanical characteristics using spark plasma sintering. Objects. Sintered bulk products made of pure aluminum and obtained at 400, 450, 500, 550, 600°C and bulk metal matrix composites Al-1%WC, Al-5%WC, Al-10%WC, Al-15%WC obtained at 600°C. Methods. Spark plasma sintering; X-ray diffractometry (XRD phase analysis); scanning electron microscopy; indentation (microhardness measurement). Results. The authors have obtained bulk composite metal matrix products with an aluminum matrix and tungsten carbide as a reinforcing component. Compacting mixtures of nanosized initial powders of aluminum and tungsten carbide using spark plasma sintering made it possible to obtain products with a WC content of 1 to 15 wt %. Taking into account the results of a preliminary series of experiments, when pure aluminum samples were sintered to determine the optimal sintering temperature, bulk composite materials were obtained. A distinctive feature of the obtained samples is their high degree of compaction, which is due to the simultaneous application of a heating current and external pressure, coupled with the relative preservation of the fine-grained structure of the material due to the short process time. The analysis of various sintering modes revealed the need to carry out sintering of composites at 600°C. The research has shown that, although adding a reinforcing phase to a metal matrix significantly reduces the degree of compaction of the material from 97.45% in the absence of an additive to 62.32% with the addition of 15%WC, an increase in the microhardness of products is observed when the concentration of the reinforcing component increases from 3.95 to 5.75 HV. This proves the possibility of reinforcing a metal material using ceramic WC particles. The results can be used in a variety of structural applications, including automotive and aerospace.

Keywords

• aluminum
• tungsten carbide
• metal matrix composites
• spark plasma sintering
• reinforcement
• microhardness