Fabrication of biodegradable materials with high strength by grain refinement of Mg–0.3 at.% Ca alloys

Enhancing the Mechanical Properties of AZ80 Alloy by Combining Extrusion and Three Pass Calibre Rolling

“…Surprisingly, the ultra-fine grain size of AZ80 alloy (~0.85 µm), which is effectively pined by nano-precipitates during caliber rolling, is even finer than that of 18 pass caliber rolled AZ31 (1.5 µm) [17]. Furthermore, the ultra-fine grain structure is even comparable with that obtained by double extruded Mg-Ca alloy (~0.7 µm) [11], and the ultra-high strength Mg-2Sn-2Ca (TX22) alloy (~0.65 µm) extruded at low temperature (200-240 • C) [28]. Accordingly, the submicron grain size, nano precipitates in present CRed AZ80 alloy can necessarily contribute to good mechanical performance.…”

“…After three pass caliber rolling, the strength of the CRed AZ80 alloy was greatly enhanced with TYS and UTS being 370 MPa and 446 MPa, respectively, both much higher than those of the corresponding as-extruded sample. The comparison of CRed AZ80 in this study with the other recently developed high strength Mg alloys [4,6,[8][9][10][11][12][13][14]17,19,21,[28][29][30][31] is shown in Figure 9. The UTS of the CRed AZ80 sample are much higher than those previously reported high strength Mg-8Al-4Sn-2Zn [21], Mg-10Sn-1Al-1Zn [29], Mg-3.5Al-3.3Ca-0.4Mn [30], and Mg-2Sn-2Ca [28] alloys.…”

“…However, their poor mechanical performance inhibits their wider commercial application. A lot of researchers have devoted themselves into developing Mg alloys with good mechanical properties via alloying with rare-earth (RE) elements [3][4][5][6], processing by severe plastic deformation (SPD) [7,8] and some other modified processing technologies [9][10][11]. For example, it was reported that Mg-Gd-Y-Zn-Zr alloy having a tensile yield strength (TYS), an ultimate tensile strength (UTS), and an elongation (EL) of 473 MPa, 542 MPa, and 8.0%, respectively was successfully fabricated [6].…”

“…Some studies have focused on fabricating high-strength RE-free Mg-Al based alloys (TYS > 300 MPa, UTS > 400 MPa UTS) by grain refinement via SPD processing technologies such as equal channel angular pressing (ECAP) [8], accumulative roll bonding (ARB) [12], multi-directional forging (MDF) [13], and high ratio differential speed rolling (HRDSR) [14]. In addition, some newly modified processing technologies such as low temperature slow speed extrusion (LTSS-E) [10] and double extrusion (DE) [11,15], were also explored as choices for producing high performance Mg alloys. However, these processing technologies are inapplicable to commercialize because of limited dimensions, low production efficiency or the complex equipment required [2].…”

A New Ultra-High-Strength AB83 Alloy by Combining Extrusion and Caliber Rolling

“…Developing low-cost rare-earth free (RE-free) Mg alloys with high strength and good ductility is considered a prerequisite for their wider commercial adoption [1][2][3]. By incorporating grain refinement, precipitation hardening, and texture hardening, high strength has been achieved so far in Mg-Al- [4,5], Mg-Zn- [6][7][8], Mg-Ca- [9,10], and Mg-Sn- [11,12] based alloys. In recent years, several Mg-Bi-based alloys with attractive mechanical properties have been obtained [13][14][15][16].…”