Using low-temperature sinterless powder method to develop exceptionally high amount of zinc containing Mg–Zn–Ca alloy and Mg–Zn–Ca/SiO2 nanocomposite

Magnesium alloys and composites have gained critical importance in several industries owing to their superior specific properties. Understanding and interpreting the influence of the processing technology, alloying and reinforcement addition on the mechanical response of magnesium is vital to improve its commercial acceptability. The presence of secondary phases in a magnesium alloy system influences the behavior of the material tremendously. The incorporation of alloying elements beyond the solubility limits using high-temperature processing technologies may result in unwanted secondary phases which might be detrimental. In this study, Mg–19Zn–1Ca alloy and Mg–19Zn–1Ca+1SiO2 nanocomposite containing an exceptionally high amount of zinc (19 wt percent) were fabricated via sinterless powder metallurgy method followed by hot extrusion by judiciously controlling temperature at each stage to minimize secondary phase formation. The addition of SiO2 nanoparticles to such alloy was further investigated. Results revealed a low incidence of secondary phase formation leading to enhanced physical and mechanical properties when compared to high weight percent Zn compositions fabricated using traditional methods and many commonly used commercial Mg alloys and stainless steel. The addition of SiO2 nanoparticles enhanced thermal stability and damping response marginally while compressive yield strength, ultimate compressive strength and fracture strain of ∼202–208 MPa, ∼380 MPa, and ∼17% were similar for both the alloy and nanocomposite. [Display omitted] •Sinteless powder metallurgy technique was used to synthesize Mg–Zn–Ca alloy and Mg–Zn–Ca–SiO2 nanocomposite.•The effect of high and low amounts of Zn and SiO2 respectively, on the microstructure and properties were studied.•Matrix grain size was refined by ∼40% in Mg–Zn–Ca–SiO2 nanocomposite.•Secondary phase formation was effectively controlled due to the low temperature operating range.•Improved thermal, damping and mechanical properties were observed when compared to many commercial alloys.