Porous NiTi alloy prepared from elemental powder sintering

Abstract

An elemental powder sintering (EPS) technique has been developed for the synthesis of porous NiTi alloy, in which Ni and Ti powders are used as the reactants and TiH2 powder is added as a pore-forming agent and active agent. Effects of various experimental parameters (sintering temperature, sintering time, and TiH2 content) on the porosity, pore size, and pore distribution as well as phase composition in experimental alloys are investigated. It is found that in order to avoid the formation of carcinogenic pure Ni phase, the porous NiTi alloy should be synthesized over a temperature of 1223 K. This gives NiTi as the main phase without any elemental phase. Substitution of Ti by TiH2 is more economic and more favorable to obtain homogeneous porous NiTi alloy. A proper selection of initial powders, ball-milling, pressing, and sintering process makes it possible to achieve the porous NiTi alloy with desired properties.

Modeling of the thermomechanical behavior of porous shape memory alloys

“…Initiating from early studies in Russia Itin et al, 1994;Shevchenko et al, 1997) and further development in China (Li et al, 1998a(Li et al, ,b, 1999, porous shape memory alloys have been developed and used primary for bone reconstruction applications (Simske et al, 1996;Ayers et al, 1999). They have lower density compared to fully dense SMAs, which allows their use in a number of lightweight applications.…”

Microstructural and Mechanical Properties of Porous 60NiTi Prepared by Conventional Press-and-sinter Method

“…There is no evidence of Ni or Ti elements in XRD patterns. Pure Ni is carcinogenic and its release in body environment can be harmful [13]. Thus, from the medical standpoint, sintering process has been successful to vanish pure Ni.…”

The effects of particle size distribution and sintering conditions on bending strength of sintered Ni-30%Fe alloys

“…PM is a practice that lessens the problems related to liquid metal casting, permits a precise composition management and the capability to manufacture a range of components shapes. Therefore, conventional sintering is seen as a viable method of making porous Ni SMA [4]. However, dense materials are not easy to attain, mostly when starting with elemental powder [5].…”