Effect of Sintering Mechanisms on the Mechanical Behaviour of SiC and Kaoline Reinforced Hybrid Aluminium Metal Matrix Composite Fabricated through Powder Metallurgy Technique

V.S.S Venkatesh,Ashish B Deoghare

doi:10.1007/s12633-021-01333-8

Abstract

Present work focusses on the fabrication of Al-10% SiC-4% Kaoline HMMC by using conventional sintering, Microwave- assisted sintering (MAS) and Spark Plasma Sintering (SPS) techniques. Tensile, Compression and hardness tests were performed as per ASTM standards to study the effect of sintering mechanisms on the fabricated HMMC specimens. Results reveal that an enhancement of 13.3% in U.T.S and 11.7% Compression strength was observed in the Spark Plasma Sintered HMMC when compared to conventional sintered composite specimens because of lesser sintering temperature, time and the absence of intermetallic compounds in the Spark Plasma Sintering process. The formation of the Al2Cu intermetallic compound was identified in the XRD pattern of conventionally sintered Al-10% SiC-4% Kaoline HMMC sample due to the high sintering time and temperature which leads to inadequate mechanical properties. The fractured surface of tensile specimens reveals the presence of cleavages on the conventionally sintered HMMC which confirms the brittle fracture, and the existence of dimples on the Microwave sintered and Spark Plasma Sintered samples which signify that the ductile mode of failure in HMMC samples. Out of the three sintering techniques, Spark Plasma Sintering exhibits superior mechanical properties and lesser porosity levels.

Highlights

Aluminium based metal matrix composites are predominantly used in defence and automobile industries due to the superior properties such as high corrosion resistance, high strength to weight ratio, and lesser cost [1, 2]
Results reveal that an enhancement of 13.3 % in U.T.S and 11.7 % Compression strength was observed in the Spark Plasma Sintered HMMC when compared to conventional sintered composite specimens because of lesser sintering temperature, time and the absence of intermetallic compounds in the Spark Plasma Sintering process
The formation of the Al2Cu intermetallic compound was identified in the XRD pattern of conventionally sintered Al-10% SiC-4% Kaoline HMMC sample due to the high sintering time and temperature which leads to inadequate mechanical properties

Summary

Introduction

Aluminium based metal matrix composites are predominantly used in defence and automobile industries due to the superior properties such as high corrosion resistance, high strength to weight ratio, and lesser cost [1, 2]. In the case of conventional sintering process, the availability of higher sintering temperature and time creates chemical interactions between the matrix and reinforcements that leads to the formation of agglomerations which reduces the mechanical strength of the composite [11, 12]. This limitation in the conventional sintering process can be overcome by adopting advanced sintering processes like Spark Plasma Sintering and Microwave sintering. Based on the above literature, limited work was carried on the Spark Plasma Sintering and Microwave sintering techniques

Methods

Results

Conclusion