Experimental Study on Surface Integrity of Ti6Al4V by Broaching

Abstract

The performance of many parts in the airplane, aircraft engine and biomedical implants is highly related to their fatigue life, which is clearly depend on the condition of their surface integrity. The geometry parameters of broaching tools have an important influence on the surface integrity after broaching Ti6Al4V alloy. Therefore, this research studies the surface integrity of Ti6Al4V by broaching. The surface integrity is studied at different geometric parameters such as rake angles (α, and α0), clearance angles (β, and β0), and radius of the cutting edge (r0) in two last teeth of the broaching tool that perform chipping. The broached surface integrity is assessed in cases of surface roughness, microstructural, residual stresses, and micro hardness. These results show that the sample broached by tool number 1 (α = 18.4, β = 3.1, α0 = 45, β0 = 9, r0 = 0.02) had higher surface integrity because it was the smoothest surface and the thinnest deformed layer among the other samples. Since the main criterions in selection of the optimal tool are to create the smoothest surface and the least deformed layer depth in the broached sample, tool number 1(α = 18.4, β = 3.1, α0 = 45, β0 = 9, r0 = 0.02) is suggested as the optimal tool.