Investigation of the Effect of Surface Burnishing on Stress Condition and Hardening Phenomena

Abstract

The purpose of this paper is to present a comprehensive study of the stress state and hardening characteristics of low-alloyed aluminium cylindrical specimens subjected to the diamond burnishing process. Diamond burnishing has a surface hardening effect on structural steels. In the present study, our aim was to check whether this surface hardening effect is also observed for other (less hard) material grades, such as low-alloy aluminium. We also aimed to determine the technological parameters at which the greatest relative increase in hardness can be achieved by burnishing. In addition to the hardness test, the changes in the residual stress state due to burnishing were also analysed. Both hardness and residual stress tests were performed in two variants. Of the 4 technological parameters (burnishing speed, feed, burnishing force and number of passes), the burnishing speed was set to constant for one variant and number of passes was set to constant at the other variant, while two levels were chosen for the other parameters. A special formula was developed to determine the relative improvement in residual stress and hardness. Our experiments were performed using a full factorial experimental design. The results show that diamond burnishing has surface hardening effect and increases of residual stress on an aluminium alloy when applying adequate technological parameters.

Analysis of the Influence of the Number of Burnishing Passes on the Geometric Structure of Aluminium Composites Surface

“…For the EN AW-AlCu4MgSi (A) alloy, the value of the coarseness reduction coefficient KRa was greater than 10, while for composites with an aluminum alloy matrix it ranged from 6 to 8. Varga and Ferencsik presented an interesting conclusion [18]. They found that the number of burnishing passes of the aluminum alloy positively influenced the surface hardness, but was of little importance for the residual compressive stresses measured in the surface layer.…”

Multi-Response Optimization of the Flat Burnishing Process with a High-Stiffness Tool in terms of Surface Characteristics

“…Van and Nguyen presented that the CYL and CIC of the burnished hole were decreased by 53.1% and 57.8 %, respectively, at the optimal point of the spray nozzle (DS), the spray elevation angle (A), flow rate (F), and air pressure (P) [17]. The impacts of the S, NP, f, and BF on the SH and residual stress for the diamond burnishing of the structural steel were analyzed by Varga and Ferencsik [18]. The authors stated that a low S could be applied to produce the desired changes.…”