Microstructures and Mechanical Properties of Precipitation-Hardenable Magnesium–Silver–Calcium Alloy Sheets

• Published in: Metals (Basel ) 2020-12, Vol.10 (12), p.1632
• Main Authors: Bian, Mingzhe, Huang, Xinsheng, Chino, Yasumasa
• Format: Article
• Language: English
• Subjects: Age; Aging (artificial); Alloy development; Alloys; Calcium base alloys; Hardenability; High strength alloys; Ion beams; Magnesium; magnesium alloys; Magnesium base alloys; Mechanical properties; Metal sheets; precipitate; Precipitates; Precipitation hardening; rolling; Rolling direction; segregation; Silver; Software; strength; Wrought alloys; Yield strength; Yield stress
• ISSN: 2075-4701; 2075-4701
• DOI: 10.3390/met10121632

Precipitation hardening provides one of the most common strengthening mechanisms for magnesium (Mg) alloys. Here, we report a new precipitation-hardenable Mg sheet alloy based on the magnesium–silver–calcium system. In a solution treated condition (T4), the strength of Mg–xAg–0.1Ca alloys is enhanced with increasing the Ag content from 1.5 wt.% to 12 wt.%. The Mg–12Ag–0.1Ca (wt.%) alloy sheet shows moderate tensile yield strengths of 193 MPa, 130 MPa, 117 MPa along the rolling direction (RD), 45° and transverse direction (TD) in the T4-treated condition. Subsequent artificial aging at 170 °C for 336 h (T6) increases the tensile yield strengths to 236 MPa, 163 MPa and 143 MPa along the RD, 45° and TD, respectively. This improvement in the tensile yield strength by the T6 treatment can be ascribed to the formation of AgMg4 precipitates lying on the {112¯0}ɑ and pyramidal planes. Our finding is expected to stimulate the development of precipitation-hardenable Mg–Ag-based wrought alloys with high strength.