Effect of Laser Cladding Processing Parameters on Nitinol’s Clad Dimensions, Microstructure, and Hardness  

作　　者：Engy M. Zain Ahmed Farid Youssef Ahmad El Sabbagh Sisa Pityana Mohamed A. Taha Engy M. Zain;Ahmed Farid Youssef;Ahmad El Sabbagh;Sisa Pityana;Mohamed A. Taha(Design and Production Engineering Department, Faculty of Engineering, Ain Shams University, Cairo, Egypt;National Laser Centre, The Council for Scientific and Industrial Research, Pretoria, South Africa)

机构地区：[1]Design and Production Engineering Department, Faculty of Engineering, Ain Shams University, Cairo, Egypt [2]National Laser Centre, The Council for Scientific and Industrial Research, Pretoria, South Africa

出　　处：《Materials Sciences and Applications》2021年第12期603-613,共11页材料科学与应用期刊（英文）

摘　　要：Nickel Titanium alloy (Nitinol) is characterized by its good mechanical properties, good damping properties in addition to its distinctive shape-memory effect and superelasticity effect besides its great bio-mechanical compatibility and corrosion resistance. These properties have empowered its applications, particularly within the bio-medical and aerospace industry. Despite these exceptional properties, the manufacturing of Nitinol by conventional methods is exceptionally troublesome and costly and consequently must be inspected. Therefore, additive manufacturing specifically laser-based ones were used recently. In this research, the effect of processing parameters of laser cladding/laser direct deposition on Nitinol’s Microstructure, Hardness and Clad Dimensions was evaluated. Systematic characterization of Nitinol samples was done utilizing Optical Microscopy and Vickers hardness tester. Samples of Nitinol were synthesized with different processing parameters using laser cladding and its properties were investigated and compared to one another to get the optimum processing parameters to synthesize a near net shape, fully dense Nitinol component with reliable properties. The results showed that there’s a processing parameter window at which the alloy possesses its best mechanical and functional properties which were of Laser power of value 1.25 Kw, Scan speed of 1.5 m/min and powder deposition rate of 1.5/1.5 RPM, these conditions resulted in the formation of martensite phase which is responsible for its functional properties with 40% volume fraction and a hardness value of 598 HV.Nickel Titanium alloy (Nitinol) is characterized by its good mechanical properties, good damping properties in addition to its distinctive shape-memory effect and superelasticity effect besides its great bio-mechanical compatibility and corrosion resistance. These properties have empowered its applications, particularly within the bio-medical and aerospace industry. Despite these exceptional properties, the manufacturing of Nitinol by conventional methods is exceptionally troublesome and costly and consequently must be inspected. Therefore, additive manufacturing specifically laser-based ones were used recently. In this research, the effect of processing parameters of laser cladding/laser direct deposition on Nitinol’s Microstructure, Hardness and Clad Dimensions was evaluated. Systematic characterization of Nitinol samples was done utilizing Optical Microscopy and Vickers hardness tester. Samples of Nitinol were synthesized with different processing parameters using laser cladding and its properties were investigated and compared to one another to get the optimum processing parameters to synthesize a near net shape, fully dense Nitinol component with reliable properties. The results showed that there’s a processing parameter window at which the alloy possesses its best mechanical and functional properties which were of Laser power of value 1.25 Kw, Scan speed of 1.5 m/min and powder deposition rate of 1.5/1.5 RPM, these conditions resulted in the formation of martensite phase which is responsible for its functional properties with 40% volume fraction and a hardness value of 598 HV.

关 键 词：Nitinol Shape Memory Alloy Additive Manufacturing HARDNESS MICROSTRUCTURE 

分 类 号：TG1[金属学及工艺—金属学]