Combining manufacturing of titanium alloy through direct energy deposition and laser shock peening processes

A Critical Review of Tool Design in Burnishing Process

Ball burnishing is a finishing technique involving plastic deformation on the workpiece surface. In this paper, the influence of the ball burnishing operation on the average roughness, tensile properties, anisotropy and work hardening of a TRIP steel was analyzed. An experimental study of the effect of the ball burnishing process on uniaxial tensile specimens was conducted using the Response Surface Methodology (RSM) based on a 32 Factorial Design (FD). The effects of burnishing force (BF) and the number of tool passes (NP) on the average roughness (Ra), the yield stress (σY) and the percentage of elongation to fracture (% El) were evaluated. The quadratic regression models were obtained to predict Ra and σY with determination coefficients (R2) of 0.85 and 0.99, respectively. The results indicated that the ball burnishing process produces a maximum reduction of Ra of 81.7% (from 1.250 to 0.229μm). Also, it was observed that the ductility of the material increased in a 25% and the yield stress and work hardening can be substantially modified. Finally, it was found that by using the ball burnishing process, the planar anisotropy of the sheet can be reduced.

Effect of the ball burnishing on the surface quality and mechanical properties of a TRIP steel sheet

Improvement in surface integrity of thermally sprayed cermet coatings

Compressive residual stress is a significant factor in influencing a fatigue failure of a mechanical component. In this perspective, the attempt has been made to induce beneficial compressive residual stress in Ti-6Al-4V alloy by using low plasticity burnishing process. The mechanism of LPB process includes rolling spherical balls made of tungsten carbide material over a material surface under fluid pressure supplied by a hydraulic unit. In this study, the cost-effective low plasticity burnishing tool with hydraulic fluid system is designed and fabricated. The LPB process was carried out on Ti-6Al-4V specimen with a suitable fixture. In this paper, the effect of burnishing process on residual stresses and cold working in Ti-6Al-4V was studied by using burnishing pressure and passes as a process parameter. The explicit module of the FE-Analysis code 6.17 was used with the aim of performing numerical simulation. The obtained experimentation results were considered to validate the results obtained by numerical FE analysis. It was found that there is good agreement between the experimental and numerical results. Both FEM simulation and experimentation results showed that hydraulic burnishing pressure is the most influential parameter in inducing beneficial compressive residual stress with less amount of coldwork.

Harish

Papers

The influence of ball and roller burnishing process parameters on surface integrity of Al 2024 alloy