Effect of Ageing Time and Deep Cryogenic Treatment on Mechanical and Wear Behaviour of Magnesium Alloy AM60
Burak KARAHİSAR Mustafa Özgür ÖTEYAKA
AbstractMagnesium alloys are lightweight and have 1,74 g/cm3 density [1]. They are used in many areas such as aerospace, defense and automotive industry because of their good mechanical properties. Gearboxes in helicopters, motor and rims in vehicles, seat frames in aircraft and cars are some examples of automotive and aerospace industry. These applications require high strength, good corrosion resistance and magnesium alloys operating at high temperatures. The most commonly used magnesium alloys in the industry are WE43, AZ91, ZA31 and ZE41. In recent years, cryogenic heat treatment has been successfully applied to light metals and alloys[2-4]. After this process, it was observed that the metallic compounds in the microstructure were precipitated to the grain and grain boundaries and the homogeneous distribution increased the mechanical properties. Recent research showed that after the cryogenic heat treatment to the magnesium alloys, the mechanical properties were increased [5] and the microstructure modification was observed [3]. In this study, the effect of solution-ageing (T6) and deep cryogenic (DC) treatment (-196oC) on wear and microstructure of magnesium alloy AM60 were investigated. To reach the objective, AM60 alloy was subjected to (T6) solution treatment at 400oC for 4h, 5h, 6h and ageing treatment at 200oC for 10h and following to deep cryogenic (DC) treatment at -196oC for 48h. Optical microscope, hardness measurement and pin-on-disc wear test were used to characterize the specimens.