Effect of Transition Metals on Thermal Stability and Mechanical Properties of Aluminum

Abstract

In the present study, binary alloys Al-X (5wt%) where (X =Cr,Ti) and a ternary alloy Al-5Cr-5Ti (all in wt.% unless mentioned) were processed via mechanical alloying technique to investigate its thermal stability and mechanical properties at high temperatures. The powders were mechanically alloyed in a ball mill for 100hrs with a ball to powder ratio of 10:1. The bulk samples of these powders were obtained by sintering in a high frequency induction sintering furnace. Change in the phases and crystallite size was evaluated by X-ray diffractometer. Crystallite size of sintered samples for binary composition Al-5Cr and Al-5Ti was estimated to be 44 nm and 46 nm respectively, whereas for ternary alloy it was noted as 42 nm. The compressive yield strength of Al-5Ti, Al-5Cr and Al-5Ti-5Cr at room temperature was found to be 471MPa, 517MPa and 545MPa respectively. Vickers micro hardness for Al-5Cr, Al-5Ti and Al-5Cr-5Ti at room temperature was found to be 146Hv, 130Hv and 160Hv. The ternary alloy, Al-5Ti-5Cr exhibited superior mechanical and microstructural properties both at ambient and elevated temperatures. The establishment of intermetallic precipitates plausibly played a vital role in enhancement of strength and hardness at higher temperatures.

Cooling Rate and Microstructural Investigation of Rapidly Solidified Spherical Mono-Sized Copper Particles

“…The variation of cooling gas may have an effect on the solidification microstructure. In order to study the effect of different cooling gas on the solidification microstructure, the surface microstructural characteristics of different cooling gas have been performed [24][25][26]. In the process of rapid solidification of spherical copper particle by POEM, the surface of copper droplets grows rapidly into supercooled liquid, and the growth of molten copper particles advances to superheated liquid at a slower rate, resulting in concave solid-liquid interface, which presents different grain boundaries on the surface of copper particles [7].…”

Advanced Composite Materials for Structural Maintenance, Repair, and Control

“…In such studies, the effect of manufacturing processes on the quasi-static and dynamic responses of aluminum alloys has been shown using experimental and modelling work [ 18 ]. The mechanical properties of lightweight aluminum alloy were also investigated in order to find the strength of the materials [ 19 , 20 ]. Additionally, the mechanical properties of composite materials and their application in a lightweight structure were defined with a few experiments [ 21 ].…”