Effect of soaking time on the preparation of porous NiTi alloy during fields-activated micro-sintering and forming technology

Dan Zhao,Jian Liu,Yi Qin,Gang Yang,Deqiang Yin,Yi Yang

doi:10.1051/matecconf/20152110007

Dan Zhao, Jian Liu + Show 4 more

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https://doi.org/10.1051/matecconf/20152110007

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Abstract

In this study, porous NiTi alloys have been successfully produced by fields-activated micro-sintering and forming technology under the pressure of 75 MPa at 1100∘C. The effects of soaking time on the porous NiTi alloys were investigated by analysing porosities, microstructures, and phase compositions of the produced alloys. The porosities of 41.2%, 38.8% and 47.2% are achieved at the soaking time of 2 min, 6 min and 10 min respectively. SEM examinations show that the pore size is varied with the soaking time and X-ray diffraction studies reveal that the main phases are NiTi, Ni3Ti and NiTi2.

Highlights

NiTi shape memory alloys have been extensively applied in mechanical, aerospace and medical industries, due to their excellent shape memory effect, good corrosion resistance, and superior mechanical properties and biocompatibility [1, 2]
The biological compatibility of porous NiTi alloys is guaranteed by adjustable porosity and pore size
From the work completed in this study, the following conclusions can be drawn: (1) Micro-FAST is a feasible technique to fabricate porous NiTi alloys in a shorter time than the other powder metallurgy techniques

Summary

Introduction

NiTi shape memory alloys have been extensively applied in mechanical, aerospace and medical industries, due to their excellent shape memory effect, good corrosion resistance, and superior mechanical properties and biocompatibility [1, 2]. As the medical implant materials, the high elastic modulus of NiTi alloys can’t match well with the low elastic modulus of human skeleton bones, which will influence the load transfer between them, causing “stress shielding” [3]. It is necessary to decrease the elastic modulus of NiTi alloys for more reliable application in medical industries. Porous NiTi alloys have been put forward as new biological implant materials [4] since the existence of pores can avoid stress shielding by decreasing the elastic modulus effectively. The biological compatibility of porous NiTi alloys is guaranteed by adjustable porosity and pore size

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