Friction and wear properties of hot pressed (Ti,Cr)B2 + MoSi2 composite in sliding against WC ball

• Coefficient of friction is a strong function of load and little effect on the sliding speed.
• Specific wear rate is observed to decrease with the increase in load for the investigated composites.
• Under the investigated sliding conditions, third body formation was observed.
• Abrasive wear mechanism was mainly observed in both flat and counter body materials.
• Severe wear was observed in WC compared with (Ti0.85Cr0.15)B2 + 20%MoSi2 composite.

Friction and wear properties of the hot pressed composite of pre-alloyed (TiCr)B2 + 20%MoSi2 (4.81 g/cm3) were studied at different loads and frequencies under reciprocative sliding, using a counter body of cemented tungsten carbide (WC-Co) ball. Coefficient of friction, wear volume and wear rate were measured. Optical microscopy and SEM-EDS analysis were carried out to understand the wear mechanism and chemistry of debris. A lowest value of coefficient of friction (COF) was measured as 0.38 at 10 N load and 10 Hz frequency. At 15 Hz frequency, the increase in load from 3 N to 10 N results in reducing the COF from 0.56 to 0.39. One order decrease in magnitude of specific wear rate was observed with an increase in load from 3 N to 10 N. Abrasive wear was the main mechanism identified in both flat and counter body materials. Severe wear was seen in counter body material (WC-Co) compared to base material of (Ti0.85Cr0.15)B2 + 20%MoSi2 composite.