Wear behaviour of a Mg alloy subjected to friction stir processing

• Published in: Wear 2013-06, Vol.303 (1-2), p.65-77
• Main Authors: Arora, H.S., Singh, H., Dhindaw, B.K.
• Format: Article
• Language: English
• Subjects: Abrasion; Abrasion resistance; Applied sciences; Contact of materials. Friction. Wear; Delaminating; Delamination; Electron microscopy; Exact sciences and technology; Friction stir processing; Magnesium base alloys; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Mg alloy; Plastic deformation; Sliding wear; Wear; Wear testing
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/j.wear.2013.02.023

In the present investigation, wear behaviour of a Mg alloy AE42 was examined under as-cast as well as friction stir processed conditions. Friction stir processing (FSP) was carried out at an optimized set of FSP parameters. Wear tests were performed in a pin-on-disc configuration using Universal Tribometer. The load range was varied from 5 to 20N, whereas sliding velocity from 0.33 to 3m/s. Worn surfaces and wear debris were analyzed using SEM and EDS for the determination of different wear mechanisms. The friction stir processed (FSPed) AE42 alloy demonstrated significant decrease in the wear rate which may be attributed to the microstructural refinement resulting in enhanced hardness and ductility of the FSPed alloy along with higher work hardening capability. At low loads, wear mechanism transformed from oxidation and abrasive wear at low sliding velocity to delamination at high velocity. At intermediate loads, oxidation and abrasion characterized the worn surface at low velocity, whereas delamination and plastic deformation were found to be major wear mechanisms at high velocities. At high loads, the corresponding mechanisms were abrasion, delamination and plastic deformation at low velocity, whereas severe plastic deformation and delamination at high velocities. ► Mg alloy AE42 friction stir processed (FSPed) under optimized conditions. ► FSPed alloy characterized by presence of sub-micron and equiaxed grain structure. ► Wear behaviour of as-cast and FSPed alloy evaluated under dry sliding conditions. ► FSPed alloy demonstrated significant reduction in the wear rates. ► Lower wear rate of FSPed alloy attributed to the microstructural refinement.