Contrasting Effects of Laser Shock Peening on Austenite and Martensite Phase Distribution and Hardness of Nitinol
Rajesh Dora Tamiridi,
Rajendra Goud,
Prabhakaran Subramaniyan,
Kalainathan Sivaperuman,
Anand Kumar Subramaniyan,
Indrajit Charit,
Srikant Gollapudi
Affiliations
Rajesh Dora Tamiridi
School of Minerals, Metallurgical and Materials Engineering, Indian Institute of Technology, Bhubaneswar 530 045, Odisha, India
Rajendra Goud
School of Minerals, Metallurgical and Materials Engineering, Indian Institute of Technology, Bhubaneswar 530 045, Odisha, India
Prabhakaran Subramaniyan
Vellore Institute of Technology, Vellore 632 001, Tamil Nadu, India
Kalainathan Sivaperuman
Vellore Institute of Technology, Vellore 632 001, Tamil Nadu, India
Anand Kumar Subramaniyan
Additive Manufacturing Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Jammu, Nagrota 181 221, Jammu & Kashmir, India
Indrajit Charit
Department of Nuclear Engineering and Industrial Management, University of Idaho, Idaho Falls, ID 83402, USA
Srikant Gollapudi
School of Minerals, Metallurgical and Materials Engineering, Indian Institute of Technology, Bhubaneswar 530 045, Odisha, India
Laser shock peening of cold rolled Nitinol was carried out at high power density (7 and 9 GW/cm2) and high overlap ratio (90%). Tensile surface residual stresses were generated in the peened material. An enhancement in surface microhardness from 351 for unpeened material to 375 and 394 VHN for the 7 and 9 GW/cm2 samples, respectively, was also observed. However, at a depth of 50 μm, the hardness of the peened material was lower than that of the as-received material. These contrasting observations were attributed to the change in the austenitic phase fraction brought about by laser interactions.
