Strain rate dependence of hardness of AlN doped SiC

Abstract Tailored nanoindentation experiments were used to determine the strain rate dependence of the hardness of AlN doped SiC produced by spark plasma sintering. It is shown that in the nanoindentation regime, where cracking is limited, the hardness of SiC reduces by 0·8 GPa/decade reduction in strain rate. This measured variation in hardness is consistent with estimates for the strain rate dependence of the lattice resistance (Peierls stress) of SiC. These experiments therefore open up the possibility to determine real constitutive equations for plasticity in SiC and other armour ceramics.