Analytical and Experimental Evaluation of the Effect of Cladding Pass Numbers on the Microstructure and Hardness of Aluminum Alloys

Friction Stir Processing (FSP) was applied as a cladding technique to produce an AA۲۰۲۴ clad layer on an AA۱۰۵۰ sheet. The cladding was carried out using a crossover multi-pass FSP method with a ۵۰% overlap. The effects of the number of FSP passes and post-heat treatment on the microstructure and properties of the clad layers were assessed. The microstructural changes during FSP and heat treatment were analyzed using Field Emission Scanning Electron Microscopy (FESEM). The findings revealed that FSP successfully produced a defect-free clad layer with a uniform metallurgical interface between the clad and base materials. Additionally, the clad layers exhibited significantly higher hardness compared to the base material. After T۴ heat treatment, the FSPed samples showed notably higher hardness values following natural aging. The highest hardness achieved was around ۱۶۰ HV after the heat treatment of samples processed with three intersecting FSP passes. The tensile strength of the clad layers increased to ۳۱۷ MPa after three intersecting FSP passes, compared to approximately ۷۰ MPa for the base Al substrate.

کلیدواژه ها:

FESEM ، SEM ، Cladding ، Multi-Pass ، Aluminum Alloys ، Microstructure