Finite Element Dynamic Analysis on Residual Stress Distribution of Titanium Alloy and Titanium Matrix Composite after Shot Peening Treatment

Abstract

The residual stress distribution introduced by shot peening (SP) in the deformed surface layer of Ti-6Al-4V and (TiB+TiC)/Ti-6Al-4V were simulated and studied via the threedimensional (3D) finite element dynamic analysis and the experimental validation. The program of ANSYS/LS-DYNA was utilized, and the 3D homogeneous and inhomogeneous models were set up. The homogeneous model was established for simulating SP process on Ti-6Al-4V. The influence of three important parameters, the shot balls' size, shot velocity and coverage rate on residual stress distribution were investigated. Numerical simulation results showed that these parameters contributed different effects on SP treatment. Using a simplified method, an inhomogeneous model for simulating SP process on (TiB+TiC)/Ti-6Al-4V was set up. The max tensile and compressive residual stress (CRS) was +1155 and −1511 MPa, respectively. Based on this stress distribution, the beneficial effect of reinforcements was indicated during deformation, retarding the damage to the matrix and keeping the adverse tensile stresses in the reinforcements. In order to verify the results of simulation, the residual stress distribution along depth was measured by X-ray diffraction (XRD) method. The residual stress distribution by experiments was agreed with the simulated results, which verified the availability of 3D finite element dynamic analysis.

Nanoindentation Characterization on Microhardness of Micron-Level TiC and TiB Reinforcements in in-situ Synthesized (TiC+TiB)/Ti-6Al-4V Composite

“…As representative reinforcements, TiC particles and TiB whiskers draw much attention because of their good properties such as high modulus, high chemical and thermal stability, clean interface without any unfavorable reaction with matrix, and the similar density and thermal expansion coefficient to matrix (Schuh and Dunand, 2001;Wagoner Johnson et al, 2003;Wei et al, 2011;Koo et al, 2012;Rastegari and Abbasi, 2013). The TiC and TiB co-reinforced TMC of (TiB+TiC)/Ti-6Al-4V has been fabricated and investigated, and some valuable results have been obtained (Lu et al, 2001c;Geng et al, 2003;Wang et al, 2005;Sun et al, 2012;Xie et al, 2012Xie et al, , 2018b. However, most research focused on the macroscopical mechanical properties of this composite, few work about the micromechanical properties of micro-level TiC and TiB reinforcements can be excavated because of the small sizes and diversified shapes.…”