Studies on the wear resistance and the structure of electrodeposited RE-Ni-W-P-SiC-PTFE composite materials

The effects of heat treatment temperature and time on the hardness and the wear resistance of RE (rare earth)-Ni-W-P-PTFE-SiC and RE-Ni-W-P-SiC composite coatings have been studied, and the results indicate that the hardness of the composite coatings is lower and the mass loss (i.e., rate of abrasion) is higher in the as-deposited state. The hardness rises and the rate of abrasion decreases with increasing heat treatment temperature; the abrasion rate is lowest and the hardness is highest at 400 °C. The hardness decreases and the rate of abrasion increases with a further rise in the temperature. The hardness and the wear resistance both increase with a rise in heat treatment time, and they reach their peak values after 2 h of heat treatment. The experimental results also show that the hardness of the coating decreases with an increase in PTFE quantity, and the wear rate diminishes correspondingly. X-ray diffraction indicates that the structure of the as-deposited RE-Ni-W-P-PTFE-SiC composite coating is of amorphous status. [Copyright &y& Elsevier]