Experimental study on chip formation and surface quality in milling of TiB2/Al alloy composites. Issue 15 (17th November 2020) - Yu, Weiwei
ABSTRACT: The in-situ TiB2 /Al alloy composites are widely used in the aerospace industry due to excellent properties. Although TiB2 /Al alloy composites have been investigated with regard to tool wear, surface defects and cutting force, chip formation is not widely covered but is crucial to understand the machinability. Therefore, milling experiments were conducted to research chip formation, evolution from continuous chips to serrated chips, and machined surface quality. The results show that the chip morphology presented two main forms: continuous chips and serrated chips. The shear angles of the chip tend to be 45° as feed per tooth increases. Compared with TiB2 /7075 composites, the chip surfaces of TiB2 /2024 composites are more rugged and prone to crack. Some cracks of chips propagate from the bottom to the inside of chips in milling of TiB2 /2024 composite, but no similar phenomena appear at the chip surfaces in milling of TiB2 /7075 composite. Furthermore, TiB2 /Al alloy composites possess better-machined surface quality. Serrated chips deterioration machined surface quality due to the tool vibration.