Stock Removal And Surface Residual Stress Of Grit Blasted Titanium

Author:  Tosha, K. and Iida, K.
Source:  Conf Proc: ICSP-4, (p.435-444)
Doc ID:  1990080
Year of Publication:  1990
Abstract:  
Recently titanium became the useful materials for aircraft and automobile industry. But the studies on titanium are not so much as that on steel, especially as to grit blasting. The characteristics of titanium for grit blasting are treated and compared with shot peening experimentally in this paper. Grit blasting is performed for commercially pure titanium (99.6 %) and carbon steel (0.45%C) with steel grit and centrifugal blasting machine. Blasting variables are grit size, grit velocity, blasting time and blasting angle. To clarify the influence of these variables on the work materials, surface roughness, hardness distribution, surface residual stress and stock removal are measured. Surface roughness of titanium is proportion to grit size and velocity as the same to steel. Depth of work hardened layer is proportion to the fourth root of kinetic energy of a grit. The maximum work hardening ratio is larger than that of steel. Stock removal of titanium is proportion to the square of blasting time, to the cube of grit size and to 4.5 power of grit velocity. In grit blasting, titanium induces less surface residual stress from 5 % to 48 % than in shot peening. The more grit size and velocity, the less the surface residual stress owing to stock removal. Surface residual stress decreases to half when blasting angle increases from 0 to 60 degree by the affect of tangential component of grit velocity. Descriptors: Grit blasting; Titanium; Shot peening; Surface roughness; Hardness distribution; Surface residual stress; Stock removal; Grit size; Grit velocity; Blasting time; Blasting angle