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Equal-channel angular pressing is a process used for the effective improvement of certain mechanical properties of various metallic alloys by producing an ultrafine-grained microstructure, although subsequent machining may be necessary in some cases for practical applications. The objective of this article was to investigate the mechanical properties and machinability of a 6061-T6 aluminum alloy produced by equal-channel angular pressing on different routes. Equal-channel angular pressing was found to improve not only hardness in certain specimens tested but also the strength of others as revealed by tensile tests. Moreover, the two most important machinability criteria, that is, cutting forces and surface roughness, were measured to find a significant reduction in cutting forces. The specimens produced by the process indeed exhibited better machinability properties as required by the cutting force criteria. Finally, a significant improvement was observed in the surface roughness of equal-channel angular pressing–produced specimens.

Ultrasonic cold forging technology is a mechanical process used to improve surface characteristics of materials by continual striking of the tool in a reciprocating motion. In this study, the proper geometrical shapes of the booster and the horn (collectively called ''the concentrator'') were obtained through numerous simulations based on the frequencies produced, the power of an ultrasonic generator (about 20 kHz), and the mechanical vibrations transferred parallel to the axis of the ultrasonic head (transducer, booster, horn, and tool). Furthermore, a pneumatic system was designed using a simulated ultrasonic cold forging technology in order to supply the static load and to prevent tool backlash in the retracting motion. Post-ultrasonic cold forging technology mechanical tests revealed an improved hardness by 17% to a depth of 150 mm and an enhanced smoothness from an initial value of 0.6-0.132 mm in the compressed layers of the surface as a result of using the ultrasonic cold forging technology process.

In this experimental study, high zinc brass was welded by friction stir welding (FSW). A threaded cylindrical tool was used for welding the brass plates in butt configuration. Mechanical tests i.e. hardness, tensile, bending, and erichsen tests were performed for evaluating the welding strength. In addition, optical microscopy (OM) and scanning electron microscopy (SEM) were used as microstructural tests for estimating the material morphology. Furthermore, temperature as a function of time was measured during the welding. The results indicated close correlation between temperature and microhardness distribution as well as the uniformity of microstructure. Moreover, the welded sample showed acceptable mechanical strength during the applied mechanical tests due to adequate primary welding parameters and tool which led to sufficient produced temperature and material bonding.