Effects of Additional Elements on Erosion and Wear Characteristics in Ti-Ni Shape Memory Alloy

摘要

The erosion and wear characteristics were investigated experimentally in Ti-Ni base alloy 3, which have the superior thermomechanical properties and the high corrosion resistance. The erosion tests were conducted by the method, which collides the compressed water of the high temperature and high pressure with the specimen. The erosion, which is caused by a combination of the cavitations and the shear stress due to the high-speed hot water flow, can be evaluated by this method. Furthermore, the sliding tests were performed at a constant sliding speed and sliding distance of 16.7 mm/s and 50 mm, respectively. Specimens were Ti-50 at percent Ni -m Ti-45 at percent Ni-5 at percent X (x : Ag, B, Fe, Nb, Pb), made by an arc melting method and a plasma sintering method, and a co-based alloy (Stellite 6) was used as a reference material. Influences of additional elements and hardness on the erosion resistance were investigated by observations of damaged surface and evaluating the maximum damaged depth and the damaged cross-sectional area. Furthermore, the effects of additional elements on wear were also investigated in relation to the specific wear rate and hardness. Results show that the Ti-Ni base alloys have higher erosion resistance than that of Co-based alloy and the Ti-Ni-Ag alloy fabricated by plasma sintering has high wear resistance equivalent to Co-based alloy.