Mechanical properties and material removal characteristics of soft-brittle HgCdTe single crystals

Mechanical properties and material removal characteristics of mercury cadmium telluride (Hg0.84C0.16Te) single crystals were investigated by the use of indentation and single point diamond turning. The nanoindentation tests showed that the average values of elastic modulus and hardness were 40 and 0.55 GPa, respectively. The fracture toughness estimated by Vickers indentation fracture toughness test was 0.200 MPa m1/2, in the predicted range of 0.204–0.235 MPa m1/2 by the Bifano model. The diamond turning experiments revealed that there was a threshold value in depth of cut that was responsible for the transition from ductile to brittle removal modes during the cutting of the Hg0.84C0.16Te single crystals. The measured critical depth of cut was between 1.5 and 2 μm, in agreement with that of 1.541 μm calculated by the Bifano model.