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https://doi.org/10.1007/s11837-020-04406-y Ó 2020 The Minerals, Metals & Materials Society

TECHNICAL ARTICLE

Mechanical and Corrosion Properties of Porous Titanium Prepared by an Electro-Assisted Powder Metallurgy Approach JIAKANG QU,1 XUE MA,1 HONGWEI XIE,1 DONGYANG ZHANG,1 QIUSHI SONG,1 and HUAYI YIN 1,2,3 1.—Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang 110819, People’s Republic of China. 2.—Key Laboratory of Data Analytics and Optimization for Smart Industry of Ministry of Education, Northeastern University, Shenyang 110819, People’s Republic of China. 3.—e-mail: [email protected]

The sintering temperature and oxygen content significantly determine the properties of porous Ti prepared by the traditional powder metallurgy route. However, it is difficult to remove the surface oxide scale on the Ti powders. Herein, porous a-Ti is prepared by an electro-assisted powder metallurgical (EPM) method using Ti powders with different particle sizes in molten CaCl2 at 850°C. The electrochemical polarization refreshes the boundaries of Ti particles and thereafter accelerates the diffusion rate of Ti atoms. The compressive strength of the EPM-Ti is 100–300 MPa, and the elastic modulus is smaller than or nearly 3 GPa. Moreover, the corrosion depth of the EPM-Ti50 lm is  36 lm after being soaked in Hanks’ solution for 90 days. The corrosion potential is  0.12 V (versus SCE), and the passivation current density is 5.14 9 106 A cm2. Therefore, the porous EPM-Ti is a promising implant material with suitable properties for human bone.

INTRODUCTION Titanium (Ti) and Ti-based alloys have been widely applied in the aviation, marine and automobile industries and implants because of their high tensile strength (250–1200 MPa), low elastic modulus (about 60–100 GPa), great wear and corrosion resistance, low density (4.5 g/cm3), etc.1 Although Ti is an ideal candidate material for implants, Chen and Thouas reported that the ‘‘stress shielding effect’’ faced in the clinical applications is a critical issue because Ti’s elastic modulus is higher than that of human bone.2 In the arthroplasty, Nagels et al. noticed that stress shielding was a long-term complication of shoulder replacement in 64 patients, and the relatively high elastic modulus of Ti leads to looseness of the implants and finally results in unsuccessful implantation.3 One of the most efficient strategies to alleviate the ‘‘stress shielding effect’’ is using porous instead of dense Ti, which Jiakang Qu and Xue Ma have contributed equally to this paper. (Received April 25, 2020; accepted September 22, 2020)

was first presented by Clemow et al.4 Then, Krishna et al. reported the performance of porous metals that were applied as load-bearing implants and noted that the porous structure can reduce the elastic modulus while allowing the ingrowth of new bone tissue and vascularization, thereby facilitating the fixation of the implants.5 According to the studies on the eff