Soban Muddassir Dar

Title : External fields assisted synthesis of high performance aluminum matrix composites

Abstract:

Automotive and aircraft industries have great potential for use of high performance aluminum matrix composites (AMCs) in light-weight and energy efficient vehicles. External field assisted synthesis of in-situ AMCs provides greater control over ceramic reinforcement particles’ size and wettability as compared to conventional AMCs. This talk is divided into two consecutive parts. In the first part of this talk, we will look at the synthesis of in-situ AMCs using three different external fields (electromagnetic, ultrasonic field and pressure) and the governing mechanisms will be descried briefly. In the second part, as an example, microstructure and properties of in-situ (Al₃Zr/Al₂O₃+ZrB₂) particles reinforced 6016Al matrix composites, produced under electromagnetic field and solidified under 10-30MPa, are investigated. Results show that the microstructure of squeezed 6016Al matrix composites has finer gain size than monolithic 6016Al alloys. The size of (Al₃Zr/Al₂O₃+ZrB₂) reinforcement particles in squeezed 6016Al matrix composites varies in 100-200nm range. The grain size of 1vol.%-6016Al matrix composite continuously decreases from 100µm to nearly 60µm; the grain size of 2vol.%-6016Al matrix composite decreases from 80µm to 50µm and ceases to decrease beyond it due to the high volume fraction of reinforcement particles. The reinforcement particles have relatively less inter-particles spacing in 2vol.%-6016Al matrix composite squeezed under high pressure. It is also observed that squeezed 6016Al matrix composites, in aged state, demonstrate higher strength and improved ductility as compared to 6016Al alloys. In addition, aged 1vol.%-6016Al matrix composite exhibit greater fracture strain than cast composite while 2vol.%-6016Al matrix composite exhibit negligible fracture strain difference in aged and cast states. The improved ductility of squeezed composites is attributed to the amorphous phase present at the α-Al/θ-Al₂O₃ interface which is expected to be the residual amorphous-Al₂O₃ phase left un-transformed to stable θ-Al₂O₃ phase. Thus, an amorphous phase layer at the particle/matrix interface is beneficial for the improved ductility of AMCs.

Audience take away:

• The audience will be able to know the current challenges in synthesis and applications of aluminum matrix composites
• External field assisted synthesis of AMCs will be introduced as a promising and novel technique for high performance composites
• The audience will be able to understand the strength-ductility paradox in alloys and composites
• This research outcomes can find practical applications in the automotive and aircraft industry

Biography:

Dr. Soban Muddassir Dar received his doctoral degree (2020) in Material Science and Engineering from Southeast University (Nanjing) China. Thereafter, he joined “High Performance Alloys and Composites Group” at Jiangsu University (Zhenjiang) China as postdoctoral researcher. Currently he is an associate professor at Jiangsu University, China. He has published several research articles in SCI/EI journals of international repute; presented his work at well known conferences and also acting as a reviewer for international journals (Elsevier, Springer). Dr. Soban’s research interests are: solidification and processing of materials, mechanical behavior of materials, electron microscopy and materials characterization.