Roller burnishing process was carried out on free cutting brass materials in the presence of fine silicon carbide abrasives in the form of paste on a pre-machined surface. The results of ‘without-paste’ burnishing (plain burnishing, PB) and ‘with-paste’ burnishing (abrasive assisted burnishing, AAB) processes are compared to examine the effect of abrasive particles in the burnishing process. A 24 full factorial design is adopted to develop the mathematical model for surface roughness regarding four process parameters like burnishing force, burnishing speed, burnishing feed and number of passes for both the cases, i.e. PB and AAB. Analysis of variance (ANOVA) was carried out to find the effect of process parameters and to check the adequacy of the models. The results show that the parameters have a significant effect on the response in PB to improve the surface roughness by 75 % than the turned components. Whereas in AAB, fine abrasive particles as a single entity controlling the response and making other parameter effects as non-significant. Surface roughness further improved by 15 % in AAB process.

Burnishing is becoming a promising surface finishing process to enhance materials surface properties.  The control of the various process parameters yields the desired surface characteristics in brass materials. In the current work, free machining brass specimens were burnished by Abrasive Assisted Burnishing(AAB) process and Plain Burnishing (PB) process using ball burnishing tool.  Response Surface Methodology was used to design the experiments in which Burnishing Force, Speed, Feed and Number of Passes were chosen as the process parameters. The minimum surface roughness achieved by PB and AAB was 0.1451 µm and 0.1041 µm respectively. The maximum surface hardness achieved using PB and AAB on the brass specimen was 207 HV and 248 HV respectively. The ball burnishing of free machining brass by AAB resulted in better surface characteristics as compared to the PB process.

Abstract:Burnishing is essentially a cold-working process used to improve properties of the machined surfaces. In present work, an attempt is made to investigate the effect of fine silicon carbide abrasive particles (in the form of a paste) in between roller burnishing tool and cylindrical components of EN24 steel. The mathematical models were developed using 2 4 full factorial design of experiments (DoE) for micro hardness in terms of four variables namely burnishing force, burnishing speed, feed and a number of passes for dry burnishing case and 'with-paste' (where burnishing is done using paste) burnishing case. Analysis of variance (ANOVA) is carried out to check the adequacy of the derived models. The results showed that micro hardness of the untreated EN24 steel can be improved by 11% and 18% for dry burnishing case and 'with-paste' burnishing case respectively compared to turned components.

The burnishing process is becoming an attractive way among post-machining, metal finishing techniques due to its excellent features. The burnishing process carried out with ball or roller, smooth out the protrusions due to the plastic deformation and increases the surface texture. This paper presents the results of three ball burnishing conditions carried out on cylindrical free machining brass components. Influence of abrasive particles (abrasive assisted burnishing, AAB) during burnishing is investigated and compared with the burnishing carried out without (plain burnishing, PB) and with-coolant (lubricated burnishing, LB) conditions. The response surface methodology (RSM) is used to optimize the microhardness in terms of four process parameters. Result obtained indicates that the microhardness of the pre-machined surfaces increases by 12-29 percent. The AAB results in 141.67 percent higher microhardness than the PB and 41 percent more than the LB condition.

Burnishing is becoming popular post-machining surface finishing technique due to its excellent features. The use of high finish and hard, ball or roller on pre-machined surface with pressure smooths out protrusions to fill the valleys and thus, resulting in lower surface roughness. In present work, ball burnishing has been carried out on free cutting brass in different burnishing conditions such as dry (Plain Burnishing, PB), lubricated (LB) and with abrasives (Abrasive Assisted Burnishing, AAB) to establish the relationship between surface roughness and the four process parameters like burnishing force, burnishing feed, burnishing speed and number of passes. The effect of using lubricants and abrasive particles is compared over PB. Design of Experiments based on Response Surface Methodology (RSM) is adopted to develop the mathematical models of second order for each above said conditions. Analysis of Variance (ANOVA) is carried out to study the effect of burnishing parameters on response and to check the adequacy of the models developed. The results showed significant reduction in the surface roughness with all cases. Surface roughness of level 0.1043 µm can be achieved from the burnishing of the turned surface having roughness level of 2.7838 µm.