Microstructure, wear and oxidation resistance of CrWN glass molding coatings synthesized by plasma enhanced magnetron sputtering

Abstract

CrWN glass molding coatings with different W contents were synthesized by plasma enhanced magnetron sputtering (PEMS). The microstructure, mechanical, wear resistance, and anti-oxidation properties of as-deposited coatings were investigated using various techniques and tests. The results showed that the as-deposited coatings exhibited typical columnar growth structure, consisting of layered CrN and W2N, and showed increased lattice expansion and hardness enhancement with increasing W content. Whereas the coating with high H/E value showed better toughness to resist fatigue deformation and fracture, which eventually resulted in excellent wear performance and low wear rate of 0.89 × 10−6 mm3/Nm. Annealing revealed that the as-deposited coating with low W content showed a slight increase in thickness and Ra value because of high volume fraction of Cr2O3 phase, which effectively delayed the oxidation reaction and suppressed the expansion of WO3 phases. With the increase in W content, the rising volume fraction of WO3 phases weakened the stabilized effects of Cr2O3 phases and eventually led to a constant increase in thickness and Ra value of the annealed coating. The mold tests confirmed that the CrWN coating showed a stable structure and excellent chemical inertness and anti-sticking performance, making it a potential coating for glass molding processes.