Tribological behavior of laser thermal sprayed Cr3C2–NiCr + 10%Ni/MoS2 composite coating on H13 hot work mould steel

Abstract

Cr _3 C _2 –NiCr+10%Ni/MoS _2 composite coating was fabricated on H13 hot work mould steel using a Laser Thermal Spraying (LTS). The friction–wear behaviors of obtained coating at 25, 400 and 700 °C were investigated using a ball–on–disc wear tester, and the effect of MoS _2 on the lubrication in the friction–wear process was also discussed. The results show that the average coefficients of friction (COFs) of Cr _3 C _2 –NiCr+10%Ni/MoS _2 coating at 25, 400 and 700 °C are 0.68, 0.55, and 0.35, respectively, and the corresponding wear rates are 25.97 × 10 ^–6 , 30.06 × 10 ^–6 , and 11.86 × 10 ^–6 mm ^3 · N ^–1 · s ^–1 , respectively. The average COF and wear rate at 700 °C are the lowest among the three kinds of operation temperatures, the MoS _2 particles and oxidation layer play a positive role of lubrication, which is the main factor of friction–wear reduction. The wear mechanism at 25 °C is abrasive wear, while those at 400 and 700 °C are primary abrasive wear, accompanied by oxidative wear.

Keywords

• laser thermal spraying (LTS)
• Cr3C2–NiCr+10%Ni/MoS2 coating
• MoS2 solid film
• coefficient of friction (COF)
• wear rate