Effect of ECAE Die Angle on Microstructure Mechanical Properties and Corrosion Behavior of AZ80/91 Magnesium Alloys

Abstract

Magnesium alloys have poor tensile strength, ductility and corrosion resistance properties associated with other engineering materials like aluminum alloys, steels and superalloys etc. Therefore, many researchers worked on equal channel angular pressing of magnesium alloys to improve the mechanical properties and corrosion resistance. In this work, the effect of channel angles on material properties was investigated during equal channel angular pressing of AZ80/91 magnesium alloy using processing route-R at 598 K processing temperature. Channel angles of 900 and 1100, common corner angle of 300 have been considered for the study. It has been revealed that the channel angle has a significant influence on deformation homogeneity, microhardness, ultimate tensile strength, ductility, and corrosion behavior of AZ80/91 magnesium alloys. Specifically, AZ80/91 Mg alloys processed through 900 channel angle i.e. die A is considered as optimal die parameter to improve above-said material properties. Investigation showing concerning as-received AZ80 and AZ91 Mg alloy indicates 11%, 14% improvement of UTS and 69%, 59% enhancement in ductility after processing through 4P through die A (90°) at 598 K respectively. Also, the corrosion rate reduces to 97% and 99% after processing the sample with 4P-ECAP die A (90°) at the same processing temperature for AZ80 and AZ91 Mg alloys respectively. This is mainly due to grain refinement and distribution of Mg17Al12 secondary phase during ECAP.

Improvement in Corrosion Performance of ECAPed AZ80/91 Mg Alloys Using SS316 HVOF Coating

“…Instead, Figure 4b shows the EDS analysis of SS316 coatings applied on AZ80-Mg alloy. Furthermore, the detailed microstructural analysis of ECAPed AZ80/91 alloys has already been presented in our previously published article [33]. A microscopic investigation of SS316-coated surfaces of the AZ80 and AZ91 Mg alloys reveals a more compact and uniform coating, as illustrated in Figures 3 and 4 in the case of both ECAPed and non-ECAPed conditions.…”

“…Results in Figures 3 and 4 show compact, uniform coatings (~80 ± 5 µm) with a welldeposited SS316 base layer, free from subsurface cracks or voids. Detailed microstructural analysis was previously presented [33]. Microhardness in HVOF-based SS316 coatings on AZ80/91 alloys varies, with the highest values near the interface and improvements seen in ECAPed samples.…”

“…Instead, Figure 4b shows the EDS analysis of SS316 coatings applied on AZ80-Mg alloy. Furthermore, the detailed microstructural analysis of ECAPed AZ80/91 alloys has already been presented in our previously published article [33].…”