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.

The Effect of the Substrate on the Microstructure and Tribological Properties of Cold Sprayed (Cr3C2-25(Ni20Cr))-(Ni-graphite) Cermet Coatings

“…The lowest wear rate (~10·10 −6 mm 3 ·N −1 ·s −1 ) and the lowest coefficient of friction (~0.44) were observed for the coatings tested at 500 °C. In turn, Hanyou et al [ 39 ] showed that the MoS 2 solid lubricant in Cr 3 C 2 -NiCr composite coatings produced by the laser thermal spray method significantly reduced the wear of coatings at room temperature—~40%, and at high temperatures, i.e., 700 °C—~65%. The wear value was 40.31·10 −6 , 31.57·10 −6 , and 31.93·10 −6 mm 3 ·N −1 ·s −1 for the Cr 3 C 2 -NiCr coatings tested at 25 °C, 400 °C, and 700 °C, respectively.…”

Microstructural and mechanical characterization of powder-pack boronized Incoloy A286 superalloy

“…The cross-sectional wear area determined by the surface profilometer device was multiplied by the perimeter value of the wear track and so the volumetric wear loss value that occurred during the test was determined. The equation (1) used to calculate the specific wear rates is given below [21].…”