Internal Stress Superplasticity in 2024 Al-SiC Whisker Reinforced Composites

Abstract

The isothermal and thermal cycling creep behavior of SiC whisker reinforced aluminum composites was investigated. Compression creep tests were performed for two volume fraction composites (10% SiC and 20% SiC), in both the longitudinal and transverse direc tions. The creep rates under thermal cycling conditions are much higher than under isothermal conditions due to the contribution of internal stresses. The aluminum matrix exhibits Newtonian flow behavior under thermal cycling conditions which results in rapid reorientation of the SiC whiskers. A creep relation is developed based on an internal- stress-plasticity model, which fits well with the thermal cycling creep data.

Advancements in SiC-Reinforced Metal Matrix Composites for High-Performance Electronic Packaging: A Review of Thermo-Mechanical Properties and Future Trends

“…MMCs are advanced materials formed by combining metals or alloys as matrices with reinforcements such as fibers, whiskers, or particles through composite fabrication techniques [ 17 ]. Numerous studies have demonstrated that the comprehensive properties of composites surpass those of the base matrix materials [ 18 , 19 , 20 , 21 , 22 ], thereby meeting various requirements. Particulate and whisker-reinforced non-continuous MMCs offer cost-effectiveness and process ability [ 23 ].…”

Particle reinforced AA 6061 and A359 aluminium alloys under cyclic thermal loading conditions

“…The key features are: (a) the material will ¯ow at stresses far below the yield stress at the high temperature of the cycle and (b) at small applied stresses, the material deforms with a stress exponent n close to 1. This gives rise to a high tensile elongation, similar to superplasticity and often referred to as internal stress superplasticity, 7,8 At stresses close to the yield strength (or high imposed strain rate) thermal cycling has very little effect on deformation.…”

Multilayered Composites Based on Ultrahigh Carbon Steel and Brass

“…Metal matrix composites have received considerable attention in the past twenty years (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Among the most extensively studied types are the whisker and fiber reinforced composites (2,(5)(6)(7)(8)(9).…”

“…Among the most extensively studied types are the whisker and fiber reinforced composites (2,(5)(6)(7)(8)(9). Particulate composites have also been emphasized; recently, aluminum composites based on particles of alumina and silicon carbide have gained considerable attention because of the economic potential that can be achieved in processing such materials by novel casting procedures (10)(11)(12).…”