Machining Characteristics and Corrosion Behavior of Grain Refined AZ91 Mg Alloy Produced by Friction Stir Processing: Role of Tool Pin Profile

Machining characteristics, wear and corrosion behavior of AZ91 magnesium alloy ‐ fly ash composites produced by friction stir processing

“…Furthermore, the Mg 17 Al 12 phase which can be observed as a network‐like structure has also been found to be significantly disturbed after friction stir processing, Figure 3a. These microstructural changes are in good agreement with the earlier reports [18, 19, 31]. A thin white layer of magnesium was noticed on the surface of the tool shoulder and also around the tool pin after friction stir processing (FSP) which is a common observation while processing magnesium alloys by friction stir processing (FSP) as reported in the other studies [33].…”

“…Improved machinability was reported for grain refined commercially pure titanium [16]. Similarly, grain refinement and the presence of alloying elements were found to be influencing factors on improving machining characteristics of magnesium alloys in our earlier study [17, 18]. Furthermore, lower edge damage was also observed for fine‐grained AZ91 magnesium alloy during drilling [19].…”

“…Friction stir processing was carried out at 1400 min −1 tool rotational speed and 25 mm/min tool travel speed. The process parameters were selected based on earlier work [18, 19]. Defect‐free surface composite was fabricated by adopting friction stir processing, Figure 1b.…”

Sliding wear behavior of AZ91/B4C surface composites produced by friction stir processing

“…Due to the intense heat generation during FSP, phase transformation in Mg alloy is a known phenomenon. In our earlier study, dissolution of intermetallic phases (β phase, Mg 17 Al 12 ) in the solid solution grains (α phase) was observed after friction stir processing in AZ91 Mg alloy [30]. Along with the grain refinement, decreased intermetallic phases and addition of secondary phase particles influence the mechanical behavior of the composites.…”

“…B 4 C particles were filled in the groove and then a pin less tool was employed to close the groove to prevent the particles scattering during FSP. Then, FSP was conducted using square taper pin tool as shown in figure 1(c) [30]. Based on preliminary experiments, the rotational and travel speeds of the FSP tool were kept at 1400 RPM and 25 mm min −1 , respectively, to obtain defect-free samples.…”