Effect of NiTi Addition on the Wear Resistance of YSZ Coatings

In this study, small fraction of NiTi (5 wt%) was added to Yttria stabilized zirconia (YSZ) top coat to improve it sliding wear resistance. The measurement of width of wear tracks after wear tests under a 15 N load for 100 m sliding distances showed that the width of wear track in NiTi-YSZ coating is shorter than that in YSZ coating which depicts the higher wear resistance of NiTi-YSZ coating samples. It is believed that the higher H/E value and pseudoelasticity effect of NiTi are two important factors which improved the wear performance of applied coatings. Also, to evaluate the role of addition of a NiTi (5 wt%)–YSZ buffer layer on the durability of YSZ coatings during wear operation, wear tests with a 20 N normal load and with a constant frequency were conducted on coated samples. It was observed that the conventional YSZ coating cracked and delaminated after about 60 m sliding distance. However, in samples which contain a NiTi (5 wt%) –YSZ buffer layer delamination was not observed until 100 m sliding distance which is attributed to the ability of NiTi for accommodation of interface stresses and hindering of premature delamination during wear test under higher loads.

Effect of NiTi Addition on the Wear Resistance of YSZ Coatings Keywords:

Air plasma spraying (APS) , Yttria stabilized zirconia (YSZ) , NiTi , Wear