Feed optimization based on force modelling and TLBO algorithm in milling Al 7075

Abstract

Aluminium alloys find wide applications in structural industries. They are only second to steel when it comes to their applications. Their wide application is due to their numerous good properties. They have a high resistance to corrosion and high fatigue strength. Their specific density, electrical and thermal properties make them stand out amongst many structural metals. Al 7075 is an alloy of aluminium in which zinc is the dominant alloying element. This alloy is in the 7xxx series of aluminium alloys, a series considered to be the strongest with yield strengths greater or equal to 500 Mpa. It, therefore, finds a wide application in aircraft structural components manufacturing and other areas where high strength is a critical property. Therefore, this paper focuses on the CNC milling process of aluminium 7075 to establish force components models and the optimal values for the critical process parameters. The work reported in this paper involved designing experiments and the development of force components and resultant force models from the experimentally acquired data. The models were validated, and their prediction ability was within the accepted range. The validated force component models were used to investigate the interaction effects of the process parameters on the respective force components. The resultant force model was eventually used as the objective function in the TLBO algorithm to acquire the optimal force and control parameters. After that, the optimal resultant force was used as a constraint parameter to demonstrate feed optimization relative to the other parameters.