Sliding wear behavior of plasma sprayed 65% (NiCrSiFeBC)–35% (WC–Co) coating at elevated temperatures

Abstract

Knowledge and optimization of tribological behavior of hot forming dies play an important role in attaining high process productivity. But research in this field has been limited. Keeping this in view, the current investigation aims to explore the potential of atmospheric plasma sprayed (APS) 65% (NiCrSiFeBC)–35% (WC–Co) coating in optimizing friction coefficients and minimizing the wear of AISI H11 and AISI H13 hot forming steels at elevated temperatures. Detailed characterization of the as-sprayed specimens was carried out using scanning electron microscopy/energy-dispersive spectroscopy and X-ray diffraction techniques. Wear and friction tests were done utilizing a high-temperature pin-on-disc tribometer under two different loads and temperatures ranging from room temperature to 800 ℃. The results have shown that the developed coating exhibited lower porosity, higher microhardness, and performed much better than the uncoated specimens. The wear mechanisms of the coated specimens were mainly abrasive at room temperatures and 400 ℃. Fatigue, tribo-oxidation, and three-body abrasion were observed as the dominant mechanisms at 800 ℃.