H. Li, Y. Gao, Y. Bin, M. Zhu, South China University of Technology, Guangzhou, China; C. Y. Chung, City University of Hong Kong, HongKong, Hong Kong
AbstractFCurrently, four methods are commonly used for producing porous NiTi shape memory alloys (SMAs) from elemental powders. These methods include conventional sintering, Self-propagating High temperature Synthesis (SHS), Hot Isostatic Pressing (HIP) and Capsule-free Hot Isostatic Pressing (CF-HIP). Conventional sintering requires long heating times and the shape and size of the pore cannot be controlled easily. One of the difficulties with SHS is the inability to control the formation of the intermetallic phases. On the other hand, the HIP and CF-HIP processes require high pressure and high temperature equipments thus making the manufacturing process expensive. This work will focus on the fabrication and characterization of porous NiTi SMA produced from elemental powders via Low Pressure Sintering. Low Pressure Sintering is sintering in low pressure that between CF-HIP and conventional sintering.
By controlling the processing parameters, such as cold pressure, sintering time, hot pressure of Low Pressure Sintering, the porous NiTi SMA resulted in round pore shape and homogeneous pore distribution. The porous NiTi SMA produced by Low Pressure Sintering also exhibits good mechanical properties, such as superior superelasticity, a high compressive strength, and superior damping performance.
KeywordsF porous NiTi SMA, low pressure sintering, superelasticity
Summary: This work focus on the fabrication and characterization of porous NiTi SMA produced from elemental powders via Low Pressure Sintering.
The porous NiTi SMA produced by Low Pressure Sintering exhibits good mechanical properties, such as superior superelasticity, a high compressive strength, and superior damping performance.
