Title: Microstructural and hardness study of stir-casted AZ91D/B4C MMCs
Authors: Sakshi Singh; Nathi Ram Chauhan
Addresses: Department of Mechanical and Automation Engineering, Indira Gandhi Delhi Technical University for Women, Kashmere Gate, Delhi-110006, India ' Department of Mechanical and Automation Engineering, Indira Gandhi Delhi Technical University for Women, Kashmere Gate, Delhi-110006, India
Abstract: This paper investigates the effect of the amalgamation of reinforced based metal matrix composites by using vacuum-based stir casting process. AZ91D Mg alloy is the matrix material and B4C with varying volume ratio fractions (2, 4, and 6%) act as reinforcement. For microstructural observation, specimens have been machined, polished and then etched. Vickers macro hardness has been evaluated under room temperature. The improvement in macro-hardness has been found in reinforced B4C/AZ91D MMCs as compared to cast-AZ91D Mg alloy. The microstructural study reveals the enhancement in homogeneity of AZ91D MMCs due to the addition of B4C reinforcement. The heterogeneous formation of α-Mg matrix and Mg17Al12 has been found to be dominant in the form of dendrite-like three-dimensional branches. The reduction in porosity and voids (microstructural defects) have been observed in B4C/AZ91D MMCs by vacuum-based stir casting as compared with cast-AZ91D Mg alloy.
Keywords: AZ91D Mg alloy; matrix; boron carbide particles; reinforcement; scanning electron microscope; hardness; phases etc.
DOI: 10.1504/IJMMP.2018.097783
International Journal of Microstructure and Materials Properties, 2018 Vol.13 No.6, pp.439 - 446
Received: 15 May 2018
Accepted: 23 Aug 2018
Published online: 09 Feb 2019 *