Effect of Nonmetallic Inclusions on Fatigue Properties of Superelastic Ti-Ni Fine Wire
Fumiyoshi Yamashita,
Yasunori Ide,
Suguru Kato,
Kyosuke Ueda,
Takayuki Narushima,
Sumio Kise,
Kouji Ishikawa,
Minoru Nishida
Affiliations
Fumiyoshi Yamashita
Department of Applied Science for Electronics and Materials, Interdisciplinary Graduate School of Engineering Science, Kyushu University, Fukuoka 816-8580, Japan
Yasunori Ide
Department of Applied Science for Electronics and Materials, Interdisciplinary Graduate School of Engineering Science, Kyushu University, Fukuoka 816-8580, Japan
Suguru Kato
Department of Materials Processing, Tohoku University, Sendai 980-8579, Japan
Kyosuke Ueda
Department of Materials Processing, Tohoku University, Sendai 980-8579, Japan
Takayuki Narushima
Department of Materials Processing, Tohoku University, Sendai 980-8579, Japan
Sumio Kise
Technology Development Department, Special Metals Division, Furukawa Techno Material Co., Ltd., Hiratsuka 254-0016, Japan
Kouji Ishikawa
Special Metals Division, Furukawa Techno Material Co., Ltd., Hiratsuka 254-0016, Japan
Minoru Nishida
Department of Advanced Materials Science and Engineering, Faculty of Engineering Sciences, Kyushu University, Fukuoka 816-8580, Japan
This study investigated the effects of the types and length of nonmetallic inclusions on fatigue properties in rotating bending fatigue testing of Ti-Ni alloy fine wire. It was fabricated to include titanium carbides Ti(C,O) and titanium oxides Ti4Ni2Ox as either single phases or a mixture of both phases as nonmetallic inclusions in Ti-Ni alloy. The fatigue strength of Ti-Ni alloy depended on the number of nonmetallic inclusions of a length of ≥2 μm. Compared with Ti(C,O), Ti4Ni2Ox is coarse. It also exhibited a trend of readily forming particles and void assemblies, which are a defect morphology that originates from nonmetallic inclusions and readily act as crack origins of fatigue fractures.
