Effects Of Ball Burnishing Research Articles

Effect of ball burnishing on surface roughness, wettability, mechanical integrity and antifouling resistance of UHMWPE

The aim of this paper is to investigate the effect of plasticity burnishing on the surface properties and antifouling resistance of UHMWPE. Ball burnishing experiments at different pressures (44–131 bar) and path strategies (1: Single Parallel and 2: Cross Parallel) were conducted. The treated surface was characterised in terms of surface roughness, surface topography, and contact angle (CA) to evaluate its surface wettability. Microhardness, wear and impact resistance were measured to assess mechanical integrity. Results show that as the burnishing pressure increased, surface roughness decreased. Strategy 2 demonstrated the most significant reduction in surface roughness. No clear relationship between burnishing pressure and CA was found. However, Strategy 2 with relatively higher pressure generated specific surface micro-texture that was responsible for higher CA over Strategy 1. Marine salt spray tests demonstrated improved water adsorption stably, creating a uniform hydration layer on the surface treated with Strategy 2. Consequently, in-field marine fouling test results revealed an improved antifouling resistance of the burnished surface. The burnishing increased microhardness, wear and impact resistance. Improvement in surface integrity was attributed to stretching and plastic yielding of entangled macromolecular chains and crystals networks in UHMWPE. The findings indicate that ball burnishing with appropriate path pattern and pressure could be a viable route to improve surface wettability and antifouling resistance.

Effects of the surface layer of steel samples after ball burnishing on friction and wear in dry reciprocating sliding

The effects of ball burnishing on tribological behaviour in dry reciprocating motion have not yet been studied. This work attempts to fill this gap. The steel disc samples after milling were ball burnished. Due to ball burnishing, the average surface height decreased to 85% and the microhardness increased to 20%. Burnishing also generated the compressive residual stresses that were responsible factor to enhance the hardness of the steel surface. Trbological tests were carried out in reciprocating motion under dry sliding conditions. A 10 mm diameter ceramic ball from WC material contacted the steel disc. Ball burnishing was found to lead to improvements in disc wear and friction of the sliding pair. The maximum decreases in friction coefficient and wear volume compared to the milled sample were 39% and 85%, respectively. Samples of the lowest amplitude and high microhardness led to the highest behaviour.

Effect of ball-burnishing on surface integrity and fatigue behaviour of 7175-T6 AA

ABSTRACT The burnishing process was performed using different feed rates, rotational speed and penetration depth parameters to alloy Al 7175-T6. Surface roughness, fatigue life and hardness of the samples were determined. Microstructural examinations of the samples were performed. In the surface roughness measurements, occurred a linear increase in proportion to the increasing feed rate. The increase in the penetration depth affected negatively the surface roughness. Significant increases were acquired in the fatigue life of the burnished samples. The hardness values of the burnishing samples are higher than the hardness value of the base material. The rotational movement of the steel ball during the burnishing process were been caused the aspect ratio of the grains in the microstructure to change.

Superficial Effects of Ball Burnishing on TRIP Steel AISI 301LN Sheets

This paper explores the consequences of applying an ultrasonic vibration-assisted ball burnishing process and its non-vibration assisted version on the topology and subsurface microstructure of a transformation-induced plasticity AISI 301LN alloy. More specifically, four different metallographic conditions provided as 1.5-mm thickness sheets and characterized by different starting martensite content (3, 10, 20 and 40 wt.%) are included in the study. Ball burnishing was performed along the lamination direction and perpendicular to it. Results show that the effect of ball burnishing is strongly correlated with the pre-existing microstructure. The steel containing the lowest quantity of initial martensite is the most affected by the process, achieving a higher residual hardening effect, similar to the untreated steel with an original martensitic content of around 40 wt.%. Moreover, the process succeeds in generating a 100-nm thick nanograin layer under the plate subsurface. Finally, no conspicuous effect of the application of vibration assistance was observed, which encourages the application of alternative measurement techniques in future works to define its effect on the properties after being ball burnished.

Effects of ball burnishing on surface properties of SKD11 mold steel

Burnishing is an energy-efficient technology to enhance the surface of mechanical parts. Metallic parts’ surfaces with hardness up to 65 HRC can be enhanced with a hydrostatic burnishing tool. This paper presents the effects of the hydrostatic burnishing on surface residual stress of the SKD11 mold steel by conducting the five-parameter orthogonal experiments using Taguchi Method. Results showed that burnishing force played the most significant role in the improvement of the magnitude of the compressive residual stresses, while the feed and the number of passes played less significant roles. Besides, the effect of burnishing direction and burnishing speed could be neglected. Single-factor experiments were conducted to provide further demonstrations of the influences of burnishing feed and number of passes on the surface properties and the results corresponded well with the orthogonal experiments in general. The single-factor experiments also showed that with the increase of burnishing feed, the surface hardness firstly experienced steady decrease and then decreased dramatically. However, the surface roughness firstly experienced steady increase and then increased dramatically. The surface hardness increased initially, but then followed a decreasing trend with the increase of the number of passes. The distribution of residual stress in the direction at an angle of 45° to the burnishing direction was related with the parity of the number of passes.

Effects of ball burnishing on the surface quality of Al 7075 alloy

Abstract The surface roughness of a part produced plays a critical role in influencing functional properties such as corrosion behavior, fatigue strength, and wear resistance. Therefore, it is very important to improve the surface roughness of Al 7075−T6 material, which is frequently used in the aerospace industry. For this reason, the finishing process, used to improve the surface quality of the parts in an easy, inexpensive and chipless manner, has recently become an interesting research topic. In this study, a ball burnishing apparatus was designed and experiments were carried out at different parameters (force, feed rate and number of passes) for the purpose of improving the surface quality of the parts. For the design of the experiments, the Taguchi method was used, thus saving time and cost savings and reducing the number of experiments required. Variance analysis (ANOVA) was performed and the effect contribution of the parameters on surface quality were obtained. As a result of the experiments, it was found that force, feed rate and the number of passes were important factors.

Surface hardening of 36 NiCrMo 6 steel by ball burnishing process

This work aims to characterize the 36 NiCrMo 6 steel in monotic traction. The tested samples were subjected to mechanical surface treatment (MST) by diamond ball burnishing. This process allow it possible to modify the physical and geometrical properties of the material. The stress-strain diagram obtained were processed and digitalised. The hardening domain was modelled and rational curves were established, taking into account the stresses triaxiality. Thus, the work hardening exponent of material considered was evaluated. The effect of ball burnishing on this exponent has studied in proceeding a comparative manner between burnished and machined surface. The results obtained show that by applying the optimal parameters for burnishing, the work hardening exponent of pre-machined surface layer can be increased by 10%, where nB = 0.407 (nT = 0.312 machined surface).

Experimental investigation on the ball burnishing of carbon fiber reinforced polymer

ABSTRACTThe polymer-based materials are generally used in all industrial applications. Even if polymer bars can be machined easily, they need surface finishing treatment after the machining process. The ductile properties make coarse roughness on the surface that causes the elastic structure of polymer materials. The carbon fiber reinforced composite materials differ from polymer-based materials by high strength and stiffness. Its structure exhibits similar performances such as metallic materials. The effect of ball burnishing on the surface quality of rod workpiece was investigated in this study. To enhance the surface quality of high strength carbon fiber reinforced polymer rod workpiece, burnishing process was performed in three different parameters (force, feed rate, number of passes) and under four different mediums (dry, wet, boron oil, and mineral oil) conditions. The results of the experiments were analyzed, and optimum burnishing parameters were determined and discussed in detail. The best surface roughness value of the CFRP material used in the experiments was obtained as burnishing force: 250 N, feed rate: 0.05 mm/rev, four passes and wet medium. According to the results of variance analysis, it was found that the CFRP workpiece is the important leading factor for surface roughness with a contribution ratio of 62.47%.

Investigation on the effect of ball burnishing on fracture toughness in spiral API X70 pipeline steel

The present work is an investigation on the effect of mechanical surface treatment using ball burnishing technique on fracture toughness in spiral API X70 pipeline steel. The burnishing operation has been carried out on three series of impact API 5L 45 Ed specimens that have been prepared according to the location of the notch towards the weld bed: BM notched specimens, FZ notched specimens, and HAZ notched specimens. In the untreated specimens, the absorbed energy in BM specimens is higher than the energy found in FZ and HAZ through the testing temperature range of 50 to −40 °C. In surface-treated specimens, there has been a significant change in the three curves of absorbed energy versus temperature. This is observed when testing temperature decrease from 20 to −40 °C since the energy in BM specimens dropped drastically reaching values lower than that obtained for FZ and HAZ specimens. At the temperature range 50 to 20 °C, the absorbed energy in ball-burnished specimens is relatively higher. At lower testing temperatures below −40 °C, the absorbed energy converged to the same value. At room temperature, hardness tests indicate that where the absorbed energy is higher, hardness is lower.

Effects of ball burnishing on surface properties of low density polyethylene

We have end milled surfaces and then applied ball burnishing to specimens of low density high molecular mass polyethylene (LDPE). An important objective was roughness minimization. For selected ball diameters, the influence of burnishing parameters such as force F and burnishing speed f on selected surface geometry parameters has been determined: roughness Ra, total height of the profile Rt, and also the two-dimensional roughness change KRa. We find the minimum value of Ra=0.57µm and the maximum value of KRa=5.1, both highly desired results. In the best case, Rt has decreased from 14.5µm to 4.0µm. Microhardness values, ball-on-disc wear values and scratch resistance testing all show property improvement of milled and burnished surfaces as compared to surfaces milled only. Burnishing decreases the wear rate by 58%.

Using specially designed high-stiffness burnishing tool to achieve high-quality surface finish

This paper is focused on the process of ball burnishing. The influence of tool stiffness on surface roughness parameters was considered theoretically, while experimental investigation was conducted to establish the influence of initial surface roughness (previous machining) on the effects of ball burnishing as the finishing process. Experimental investigations were conducted over a wide interval of most influential process parameters (burnishing forces, burnishing feed, and number of burnishing passes). The material used in the experiments was aluminum alloy EN AW-6082 (AlMgSi1) T651. Burnishing was performed using a specially designed tool of high stiffness. Statistical analysis of experimental data revealed strong correlation between roughness, Ra, and burnishing force, burnishing feed, and number of passes for the three surfaces, each with different roughness parameters. Particular combinations of process parameters yielded very low surface roughness, Ra, equivalent to polishing. It is worth noting that high surface quality can be achieved with relatively small burnishing forces, which differs from the investigations published so far. Contrary to conventional approaches, which are based on elastic tool systems, the authors propose the burnishing process to be conducted with high-stiffness tools. Further investigation shall be focused on optimization of burnishing process parameters in order to achieve surface finish equivalent to high polish.

The effect of ball burnishing on heat-treated steel and Inconel 718 milled surfaces

In this paper the use of the ball burnishing process to improve the final quality of Inconel 718 surfaces is studied. This process changes the roughness and residual stresses of the previously end milled surfaces, achieving the finishing requirements for engine components. Both the burnishing system and main parameters are taken into account, considering their influence on finishing. Workpiece surface integrity is ensured due to the compression effect of this surfacef enhancement process and its associated cold working. Results of different tested pieces are discussed in relation to the maximum and mean surface roughness achieved microstructure and surface hardness. Results of heat-treated low carbon mould steel P20 (32 HRC) are compared with those for the nickel alloy Inconel 718 (solution treated and age hardening, 40 HRC). The main conclusions are that using a large radial width of cut in the previous end milling operation, together with a small radial width of cut during burnishing can produce acceptable final roughness. And compression cold working is higher and deeper in the Inconel 718 than in the steel case.