Evaluation of Flow Stress in Turning Operation for Hybrid Aluminum 6061 Composite using Zerilli-Armstrong Model

Abstract

Aluminium-based composites are becoming more widely used in the aerospace, automotive and defence industries due to the demand for materials that are lightweight and high in strength, along with a continuous drive for the increase in performance. This study examined the flow stress behaviour and machinability of the Al6061 composites reinforced with yttrium oxide (Y₂O₃) and graphite particles. In total, four different combinations of Y₂O₃ were fabricated and machined as part of the controlled turning operations. Emphasis was placed on mapping the relationship between cutting forces, strain hardening and thermal softening whilst machining. The Zerilli-Armstrong (Z-A) constitutive model incorporates the effects of dislocation mechanics and thermal activation processes in modelling flow stress behaviour. As part of the research finite element analysis (FEA) was undertaken to perform machining simulations, particularly in relation to the stress, strain and temperature distributions being generated in the cutting zone. The results in both conditions concluded that the Z-A model more accurately described the deformation response of the reinforced Al6061 composites under different machining conditions.