DAMAGE ACCUMULATION IN THE V95\3% TIC METALMATRIX COMPOSITE DURING DEFORMATION AT HIGH TEMPERATURES

Abstract

Damage accumulation in a dispersion-strengthened metal matrix composite was studied at deformation temperatures ranging between 300 and 500°C. The composite has the V95 alloy matrix (the Russian analogue of the 7075 alloy) reinforced by titanium carbide (TiC) particles in a volume content of 3%. The composite was made by ex-situ liquid-phase technology. Damage calculation is based on the data of the evolution of the elastic modulus value obtained by the instrumented microindentation technique. It has been experimentally found that, under compression at the macroscale, the composite has the best plasticity at a temperature of 400°C. The plasticproperties at a deformation temperature of 500°C are significantly lower than at 300 and 400°C. ranging from 300 to 500°C and strain rates ranging between 0.1 and 10 s-1. The paper presents experimental dependences between flow stress and strain for temperatures ranging from 300 to 500°C and strain rates ranging between 0.1 and 10 s-1. Based on these data, finite element simulation of specimen compression was carried out, which makes it possible to describe the influence of loading conditions on the evolution of the stress state characterized by the Lode-Nadai coefficient mσ and the σ/T ratio, where σ is mean normal stress and T is tangential stress intensity.