Development of Metal Matrix Composites Using Microwave Sintering Technique

Abstract

In this book chapter, aluminum (Al)-based metal matrix composites (AMMCs) with various reinforcing ceramic particles, such as SiC, Si 3 N 4 , and Al 2 O 3 , were produced by microwave sintering and subsequent hot extrusion processes. The role of various nano/ micro-sized reinforcements in altering the structural, mechanical, and thermal properties of the microwave-extruded composites was systematically studied. The X-ray diffraction (XRD) patterns indicated that the main components were Al, SiC, Si 3 N 4 , and Al 2 O 3 for the studied Al-SiC, Al-Si 3 N 4 , and Al-Al 2 O 3 composites, respectively. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) elemental mapping confirm the homogeneous distribution of reinforcing particles in the Al matrix. Mechanistic studies revealed that the Al-Si 3 N 4 metal matrix composite exhibited superior hardness, ultimate compression/tensile strength, and Young's modulus, while having a lower coefficient of thermal expansion compared to other studied Al composites. Findings presented are expected to pave the way to design, develop, and synthesize other aluminum-based metal matrix composites for automotive and industrial applications.

Effect of microwave sintering on the microstructure and mechanical properties of Al-Al2O3-Si3N4 hybrid composite fabricated by powder metallurgy techniques

“…Good fracture toughness parameters for 2 wt.-% mixed Al 2 O 3 and Si3N4 were found in comparison to the pure sintered sample. Matli et al 12 prepared Al-based metal From archival literature, it has been observed that most of the automobile manufacturing industries used SiC and Al 2 O 3 as reinforcement with aluminum alloy in the fabrication of different parts. 5 In the present study, Si 3 N 4 is used along with Al 2 O 3 in the partial replacement of SiC.…”

Advanced Metal Matrix Nanocomposites

“…They mixed different contents of CNTs (0.5 to 2.0 wt%) with the metallic powders in isopropanol; upon drying, the mixtures were uniaxially compacted and then sintered at elevated temperatures at different sintering times (i.e., 90 min at 640 • C for Al/CNT nanocomposites and 120 min at 950 • C for Ni/CNT nanocomposites). The PM technique, assisted with a novel "MW sintering" has been used extensively to produce different grades of Mg matrix nanocomposites [43][44][45][46]; MW heating is used to rapidly and effectively heat up the mixed powder particles as heat is generated within the powders, internally, and radiates outward (core-to-surface), which is contrary to what occurs in the conventional sintering process (surface-to-core) [44,45].…”