The effect of equal channel angular pressing on the tensile properties and microstructure of two medical implant materials: ASTM F-138 austenitic steel and Grade 2 titanium

Recent Progress on Nanocrystalline Metallic Materials for Biomedical Applications

“…Previous studies have found that NC ASTM F-138 austenitic SSs have higher mechanical strength than their CG counterpart [15,50,51]. Heidari et al found that the ASTM F2581 nanocrystalline stainless steels had 824 MPa yield strength, and the strength exceeded 1 GPa [51].…”

“…Researchers find that the mechanical performance of NC pure Ti is superior to that of conventional commercial CG Ti [15]. The strength of the NC Ti is nearly twice than that of conventional CG Ti: the σ YS and σ UTS of CG pure Ti were tested to be about 530 MPa and 700 MPa, respectively; after equal-channel angular pressing (ECAP), the CG Ti transformed to NC Ti and showed much higher σ YS of 1267 MPa and σ UTS of 1330 MPa [16].…”

“…Shahmir et al [20] obtained a good combination of strength and elongation in high-pressure torsion (HPT)-processed NC Ti at elevated temperatures ranging from 573 to 773 K. The strength, microhardness, and elongation of the NC pure Ti (Grade 2) with a grain size of 70 nm were measured as 945 MPa, 300 HV, and 9% at room temperature and approximately 350 MPa, 230 HV, and 130% at 673 K, respectively. Filho et al [15] fabricated NC pure Ti (grade 2) with ECAP followed by cold rolling and found that this method gives the best strength-ductility combination. González-Masís et al found that the nanocrystalline Ti-Nb-Zr-Ta-Hf had a combination of high hardness of 564 HV and moderate elastic of 79 GPa [21].…”

Effects of processing conditions on microstructure and mechanical properties of equal-channel-angular-pressed titanium

“…In various studies, ECAP processing was utilised to produce ultrafine-grained/nanocrystalline titanium [5,[8][9][10][11][12][13][14][15][16][17][20][21][22][23][24][25][26][27][28][29][30]. Titanium was processed by a singlepass ECAP [5,17,21,24,25,27] and multiple-pass ECAP-B A [30], ECAP-B C [7,8,10,12,14,15,[22][23][24][25]29], and ECAP-C [9,28,30]. In studies such as [7,8,14,17,29,30], titanium was ECAPed up to 8 passes while in [5,…”

“…The microstructural and mechanical properties of titanium processed by ECAP followed by drawing [5,16,17], extrusion [8], forging [14], HPT [28], or rolling [9,10,12,15,24,29] have also been investigated. The incorporation of a MT process after ECAP results in an additional reduction in the grain size, providing an enhancement in the mechanical properties.…”