Detection of grinding-induced defects in titanium matrix composites by polarized laser scattering

Abstract

In high-speed grinding of TiC-reinforced titanium matrix composites (TiC-TMCs), grinding-induced defects, e.g., chinks and cracks, respectively caused by titanium matrix smearing and TiC fracturing, can reduce the fatigue life of a ground part. Since TiC-TMCs have heterogeneous and discontinuous material properties, it is difficult to detect the defects of a ground part by the traditional non-destructive methods. In this study, the polarized laser scattering (PLS) detection method was applied for the first time to detecting the grinding-induced defects of the additively manufactured (AMed) TiC-TMCs. Different surface morphologies were obtained at various grinding speeds. A correlation between the polarized laser scattering signal and the percentage of defects was revealed. With an increase in grinding speed, the surface and subsurface defects were reduced, and the PLS signal intensity was decreased correspondingly. This study provides a new non-destructive defect detection method for metal matrix composite parts.