RETRACTED ARTICLE: Effects of roller burnishing process parameters on surface roughness of A356/5%SiC composite using response surface methodology
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Abstract
In this study, a simple roller burnishing tool was made to operate burnishing processes on A356/5%SiC metal matrix composite fabricated by electromagnetic stir casting under different parameters. The effects of burnishing speed, burnishing force and number of burnishing passes on the surface roughness and tribological properties were measured. Scanning electron microscopy (SEM) graphs of the machined surface with PCD (insert-10) tool and roller burnished surface with tungsten carbide (WC) roller were taken into consideration to observe the surface finish of metal matrix composites. The mechanical properties (tensile strength, hardness, ductility) of A356/5%SiC metal matrix composites were studied for both unburnished samples and burnished samples. The results revealed that the roller burnished samples of A356/5%SiC led to the improvement in tensile strength, hardness and ductility. In order to find out the effects of roller burnishing process parameters on the surface roughness of A356/5%SiC metal matrix composite, response surface methodology (RSM) (Box–Behnken design) was used and a prediction model was developed relevant to average surface roughness using experimental data. In the range of process parameters, the result shows that roller burnishing speed increases, and surface roughness decreases, but on the other hand roller burnishing force and number of passes increase, and surface roughness increases. Optimum values of burnishing speed (1.5 m/s), burnishing force (50 N) and number of passes (2) during roller burnishing of A356/5%SiC metal matrix composite to minimize the surface roughness (predicted 1.232 µm) have been found out. There was only 5.03% error in the experimental and modeled results of surface roughness.
Keywords
Burnishing speed Burnishing force Response surface methodology (RSM) Box–Behnken design Desirability function1 Introduction
Increasing need for new lightweight materials with good mechanical properties has led to the development of a new generation of composite materials over recent decades, even though these increased mechanical properties after the addition of reinforcement create major challenges for machining with good surface quality. Composite materials with good mechanical properties, such as good strength, toughness and greater hardness, cause serious tool wear when traditional machining is used [1]. Burnishing is a low-cost surface treatment process and can be applied to improve surface quality. During burnishing, the generated pressure exerted by the tool exceeds the yield point of part surface at the point of contact, and causes a small plastic deformation. This plastic deformation created by roll or ball burnishing is a displacement of the material that flows from the peaks into the valleys under pressure, and results in a mirror-like surface finish with a strain-hardened, wear, and corrosion-resistant surface [2]. Both ball burnishing and roller burnishing are cold-working processes that do not involve material removal, and can produce work hardening of the part surface. Roller burnishing is applied to cylindrical workpieces on both external and internal surfaces, and its tools are similar to roller bearings [3].
El-Axir [4] studied the influence of burnishing speed, force, feed, and number of passes on both surface microhardness and roughness. Mathematical models were presented for predicting the surface microhardness and roughness of St-37 caused by roller burnishing under lubricated conditions. Variance analysis was conducted to determine the prominent parameters and the adequacy of the models. From an initial roughness of about surface roughness 4.5 µm, the specimen finished to a roughness of 0.5 µm. It is shown that the spindle speed, burnishing force, burnishing feed and number of passes have the most significant effect on both surface microhardness and surface roughness. El-Khabeery and El-Axir [5] presented an investigation of the effects of roller-burnishing upon surface roughness, surface microhardness and residual stress of 6061-T6 Al alloy. Mathematical models correlating three process parameters including burnishing speed, burnishing depth of penetration and number of passes, were established. It is shown that low burnishing speeds and high depth of penetration produce much smoother surfaces, whereas a combination of high speed with high depth leads to rougher surfaces because of chatter. The optimum number of passes that produces a good surface finish is found to be 3 or 4. Luo et al. [6] conducted the experiments with a simply designed cylindrical surfaced polycrystalline diamond tool. It was found that smaller parameters did not mean lower surface roughness or waviness, and different optimum burnishing parameters could be got under different burnishing conditions. Luo et al. [7] examined the effects of the burnishing parameters on the burnishing force and the surface microhardness with theoretical analysis and concluded that the burnishing feed and depth were the most significant factors. Luo et al. [8] compared theoretical results with the experiments in which Al alloy LY12 was selected as material for making the specimens. A new cylindrical polycrystalline diamond tool was developed for the burnishing process, and it showed that the theoretical model was basically correct in describing the burnishing process. Yeldose and Ramamoorthy [9] presented an investigation for the comparison of the effects of the uncoated and TiN coating by reactive magnetron sputtering on EN31 rollers in burnishing with varying process parameters. It was observed that the burnishing speed, burnishing force and number of passes had almost equal effect on the performance of the roller in burnishing, particularly with reference to the surface finish of the components produced. El-Taweel and El-Axir [10] showed that the burnishing force with a contribution percent of 39.87% for surface roughness and 42.85% for surface micro-hardness had the dominant effect on both surface roughness and micro-hardness followed by burnishing feed, burnishing speed and then by number of passes. Klocke et al. [11] observed an additional influence on the surface roughness for high roller ball diameters. Franzen et al. [12] showd that the process parameters of the roller burnishing process had a strong influence on the surface topology of the friction elements and their tribological properties. Sagbas [13] developed a quadratic regression model to predict surface roughness using response surface methodology (RSM) with rotatable central composite design (CCD). In the development of predictive models, burnishing force, number of passes, feed rate and burnishing speed were considered as model variables. Korzynski et al. [14] examined the effects of burnishing parameters on surface roughness and obtained the relevant mathematical models, and multinominals of the second order that also allow for the interaction of input factors for burnished 42CrMo4 alloy steel shafts. From the analysis it was concluded that surface microhardness increased by up to 29%. Świrad [15] introduced the new diamond sinter with ceramic bonding phase in the form of Ti_{3}SiC_{2} as the tool material for sliding burnishing to eliminate existing defect of the applied composites. Tadic et al. [16] achieved high surface quality with relatively small burnishing forces for Al alloy EN AW-6082 (AlMgSi1) T651. Balland et al. [17] investigated the mechanics of roller burnishing through finite element simulation and experiments. Balland et al. [18] proposed a finite element modeling of the ball burnishing process and analyzed the effect of the burnishing process on the material.
On the basis of literature review, it was found that no researcher had investigated the mechanical properties and surface roughness of A356/SiC composite (Al/SiC composite) after roller burnishing with tungsten carbide rollers. Hence, in view of the above facts, an investigation was carried out to find the effects of roller burnishing process parameters on the surface roughness of A356/5%SiC metal matrix composite. The roller burnished A356/SiC composite was characterized in terms of the SEM micrograph of surface, tensile strength, ductility, hardness. In order to properly design a burnishing process, roller burnishing process parameters were optimized with respect to surface roughness using a Box–Behnken design RSM.
2 Materials and methods
2.1 Matrix alloy
Chemical composition of A356 alloy [19]
Element | Composition /wt.% |
---|---|
Si | 6.5–7.5 |
Fe | 0.2 |
Cu | 0.2 |
Mn | 0.1 |
Mg | 0.25–0.45 |
Zn | 0.1 |
Ti | 0.1 |
Al | Balance |
Properties of A356 alloy [19]
Properties | Values |
---|---|
Liquidus temperature /°C | 615 |
Solidus temperature /C | 555 |
Density /(g·cm^{-3}) | 2.685 |
2.2 Reinforcement material
Silicon carbide (beta) particle parameters
Properties | Values |
---|---|
Purity /% | 95 |
Average particle size /µm | 25 |
Density /(g·cm^{−3}) | 3.21 |
Morphology | Spherical |
Properties of silicon carbide
Properties | Values |
---|---|
Melting point temperature /°C | 2,200–2,700 |
Hardness (Vickers) | 2,800–3,300 |
Density /(g·cm^{−3}) | 3.2 |
Crystal structure | Hexagonal |
2.3 Roller burnishing tool
2.4 Fabrication of metal matrix composite
2.5 Selection of roller burnishing process parameters and their levels
Process parameters with their ranges
Input parameters | Ranges |
---|---|
Burnishing speed /(m·s^{−1}) | 0.83–1.5 |
Burnishing force /N | 50–150 |
Number of passes | 2–4 |
2.6 RSM
Objective of the present work is to concentrate on the second strategy: statistical modeling to develop an appropriate approximating model between the response y and independent variables, ξ_{1}, ξ_{2}, ··· , ξ_{k}.
2.7 Planning of experiments
Design matrix and experimental results
Standard order | Run | Burnishing speed /(m·s^{−1}) | Burnishing force /N | Number of passes | Surface roughness /µm |
---|---|---|---|---|---|
10 | 1 | 1.17 | 150 | 2 | 0.500 |
2 | 2 | 1.50 | 50 | 3 | 0.798 |
3 | 3 | 0.83 | 150 | 3 | 2.700 |
15 | 4 | 1.17 | 100 | 3 | 1.150 |
8 | 5 | 1.50 | 100 | 4 | 1.300 |
1 | 6 | 0.83 | 50 | 3 | 1.700 |
6 | 7 | 1.50 | 100 | 2 | 0.100 |
4 | 8 | 1.50 | 150 | 3 | 1.800 |
7 | 9 | 0.83 | 100 | 4 | 2.200 |
9 | 10 | 1.17 | 50 | 2 | 0.200 |
16 | 11 | 1.17 | 100 | 3 | 1.200 |
17 | 12 | 1.17 | 100 | 3 | 1.290 |
14 | 13 | 1.17 | 100 | 3 | 1.270 |
5 | 14 | 0.83 | 100 | 2 | 1.000 |
13 | 15 | 1.17 | 100 | 3 | 1.250 |
11 | 16 | 1.17 | 50 | 4 | 1.100 |
12 | 17 | 1.17 | 150 | 4 | 2.200 |
3 Results and discussion
3.1 Microstructure of metal matrix composite
3.2 Surface layer of A356/5%SiC composites
3.3 Mechanical properties
Observations of tensile strength, ductility and hardness of composites
Sample No. | Turning with PCD (insert-10) tool | Roller burnishing with WC roller | ||||
---|---|---|---|---|---|---|
Tensile strength /MPa | Percentage elongation (ductility) /% | Hardness /BHN | Tensile strength /MPa | Percentage elongation (ductility) /% | Hardness /BHN | |
1 | 292.60 | 4.50 | 75.60 | 299.45 | 5.50 | 82.00 |
2 | 298.50 | 5.20 | 82.35 | 303.56 | 6.80 | 85.66 |
3 | 304.45 | 6.65 | 86.66 | 307.55 | 7.25 | 92.33 |
4 | 301.22 | 6.40 | 84.80 | 306.45 | 7.11 | 89.66 |
5 | 304.45 | 6.45 | 87.50 | 312.00 | 7.50 | 94.50 |
Average values | 300.24 | 5.84 | 83.38 | 305.80 | 6.83 | 88.83 |
3.4 Analysis of surface roughness of A356/5%SiC roller burnished samples
ANOVA for surface roughness
Source | Sum of square | DF | Mean square | F value | p value Prob. >F | |
---|---|---|---|---|---|---|
Model | 7.63 | 9 | 0.85 | 93.90 | < 0.0001 | Significant |
A (Burnishing speed) | 1.62 | 1 | 1.62 | 179.68 | < 0.0001 | |
B(Burnishing force) | 1.45 | 1 | 1.45 | 160.28 | < 0.0001 | |
C(Number of passes) | 3.13 | 1 | 3.13 | 346.23 | < 0.0001 | |
AB | 1.000 x 10^{−6} | 1 | 1.000 x 10^{−6} | 1.108 x 10^{−4} | 0.9919 | |
AC | 0.000 | 1 | 0.000 | 0.000 | 1.0000 | |
BC | 0.16 | 1 | 0.16 | 17.73 | 0.0040 | |
A ^{2} | 0.47 | 1 | 0.47 | 51.96 | 0.0002 | |
B ^{2} | 0.14 | 1 | 0.14 | 15.75 | 0.0054 | |
C ^{2} | 0.73 | 1 | 0.73 | 80.63 | < 0.0001 | |
Residual | 0.063 | 7 | 9.026 x 10^{−3} | |||
Lack of fit | 0.050 | 3 | 0.017 | 5.21 | 0.0724 | Not significant |
Pure error | 0.013 | 4 | 3.220 x 10^{−3} | |||
Cor total | 7.69 | 16 | ||||
Std. dev. | 0.095 | R-square | 0.9918 | |||
Mean | 1.28 | Adj-R squared | 0.9812 | |||
C.V./% | 7.42 | Pred R-squared | 0.8927 | |||
Press | 0.82 | Adeq precision | 34.993 |
The determination coefficient (R^{2}) was used to check the goodness of fit of the model. The coefficient of determination value (0.9918) was calculated for response. This indicates that 99.18% of experimental data certify the rapport with the data predicted by the model. The R^{2} value is always between 0 and 1, and its value illustrates correctness of the model. Coefficient of determination value (0.9918) should be close to 1.0 for a good statistical model. The adjusted R^{2} value regenerates the phrases with the significant terms. Adj R^{2} (0.9812) is also high to proponent for a high significance of the model. The Pred R^{2} (0.8927) suggests that the model could explain 95% of the changeability in anticipating new observations. Low value of coefficient of variation (7.42) expresses that deviations between experimental values and predicted values are low. Signal to noise ratio measures by Adeq precision. Adeq precision greater than 4 is desirable. In this study, Adeq precision value is 34.993, which reveals adequate signal.
3.5 Analysis of desirability
3.6 Effect of rolling burnishing process parameters on surface roughness
Burnishing is a superficial plastic deformation process used as a surface smoothing and surface enhancement finishing treatment after some machining processes to generate a compact and wear-resistant surface for longer and efficient component life [29]. In this study, the surface roughness of A356/5%SiC metal matrix composite under roller burnishing with WC oller was established, in which roller burnishing speed, roller burnishing force and numbers of passes are taken into consideration. The mathematical models, in terms of roller burnishing process parameters, were developed for surface roughness prediction using RSM on the basis of experimental results. The significance of these parameters on surface roughness of A356/5%SiC had been established by ANOVA.
3.6.1 Effect of burnishing speed on surface roughness
The outcomes of the roller burnishing speed with respect to surface roughness are shown in Figs. 17 and 18, respectively. It can be noticed that surface roughness decreases with the increase in roller burnishing speed. There are variations in the surface roughness, when the roller burnishing speed varies. Higher roller burnishing speed (1.5 m/s) increases the surface temperature of workpiece. Metallic bond of metal matrix composite materials becomes soft due to increased surface temperature of workpiece, and resistance offered by metal matrix composite material against roller burnishing tool becomes low.
3.6.2 Effect of burnishing force on surface roughness
3.6.3 Effect of number of passes on surface roughness
3.7 Confirmation experiment
Confirmation result
Response | Surface roughness |
---|---|
Prediction /µm | 1.232 |
SD | 0.095 |
SE (n = 1) | 0.104 |
95% PI low | 0.9859 |
95%PI high | 1.4781 |
4 Conclusions
- (i)
SEM micrographs of the surfaces of A356/5%SiC metal matrix composites generated under conditions in roller burnishing with WC roller show much smooth surface as compared to surface generated under condition in turning with PCD (insert-10) tool. Average surface roughness of machined A356/5%SiC composites with PCD (insert-10) tool is observed 3.732 µm, while the average surface roughness of roller burnished samples with WC roller is observed 1.232 µm (predicted). Reduced surface roughness of A356/5%SiC metal matrix composite under roller burnishing is 66.98%. Average tensile strength of machined A356/5%SiC composite with PCD (insert-10) tool is 300.2 MPa. While after the roller burnishing with WC rollers, it is 305.80 MPa. Tensile strength has improved by 1.81%. The average value of percentage elongation (ductility) of machined A356/5%SiC composites with PCD (insert-10) tool is 5.84. On the other hand average percentage of elongation of composite under roller burnishing was found to be 6.83. Improved ductility of A356/5%SiC metal matrix composite under roller burnishing is found 14.49%. From the results, average hardness of machined A356/5%SiC composite with PCD (insert-10) tool is 83.38 BHN, after the roller burnishing with WC roller 6.13% hardness improves. Within the chosen roller burnishing process parameters range, higher roller burnishing speed (1.5 m/s), lower roller burnishing force (50 N), and lower number of passes (2) are preferred for good surface finish of A356/5%SiC metal matrix composite under roller burnishing with WC roller.
- (ii)
Within the roller burnishing process parameters range, surface roughness of A356/5%SiC decreases. By increasing the roller burnishing speed while increasing the roller burnishing force and number of passes from minimum to maximum limits, the surface roughness of A356/5%SiC composite increases. Based on ANOVA, roller burnishing speed, roller burnishing force, and number of passes are found to be suitable for surface roughness with regression p-value less than 0.05 and lack of fit more than 0.05. Within the roller burnishing process parameters range, it is found that the parameters which affect the surface roughness in descending order are as follows: number of passes, roller burnishing speed and roller burnishing force. The minimum value of surface roughness with desirability 1 is obtained to be 0.086 µm at roller burnishing speed of 1.28 m/s, burnishing force of 61.30 N and number of passes of 2.06. An empirical relationship has been developed to predict the surface roughness incorporating roller burnishing process parameters at 95% confidence level. The predicted value for surface roughness is found 1.232 µm. There is only 5.032% error in the experimental and modeled results.
References
- 1.Yan BH, Wang CC, Chow HM et al (2000) Feasibility study of rotary electrical discharge machining with ball burnishing for Al_{2}O_{3}/6061Al composite. Int J Machine Tools Manuf 40(10):1403–1421CrossRefGoogle Scholar
- 2.Gharbi F, Sghaier S, Hamdi H et al (2012) Ductility improvement of Al 1050A rolled sheet by a newly designed ball burnishing tool device. Int J Adv Manuf Technol 60:87–99CrossRefGoogle Scholar
- 3.Lopez de Lacalle LN, Lamikiz A, Sanchez JA et al (2007) The effect of ball burnishing on heat-treated steel and Inconel 718 milled surfaces. Int J Adv Manuf Technol 32:958–968CrossRefGoogle Scholar
- 4.El-Axir MH (2000) An investigation into roller burnishing. Int J Machine Tools Manuf 40(11):1603–1617CrossRefGoogle Scholar
- 5.El-Khabeery MM, El-Axir MH (2001) Experimental techniques for studying the effects of milling roller-burnishing parameters on surface integrity. Int J Machine Tools Manuf 41(12):1705–1719CrossRefGoogle Scholar
- 6.Luo H, Liu J, Wang L, Zhong Q (2005) Investigation of the burnishing process with PCD tool on non-ferrous metals. Int J Adv Manuf Technol 25:454–459CrossRefGoogle Scholar
- 7.Luo H, Liu J, Wang L, Wang Q (2006) The effect of burnishing parameters on burnishing force and surface microhardness. Int J Adv Manuf Technol 28:707–713CrossRefGoogle Scholar
- 8.Luoa H, Liu J, Wang L, Zhong Q (2006) Study of the mechanism of the burnishing process with cylindrical polycrystalline diamond tools. J Mater Process Technol 180:9–16CrossRefGoogle Scholar
- 9.Yeldose BC, Ramamoorthy B (2008) An investigation into the high performance of TiN-coated rollers in burnishing process. J Mater Process Technol 207:350–355CrossRefGoogle Scholar
- 10.El-Taweel TA, El-Axir MH (2009) Analysis and optimization of the ball burnishing process through the Taguchi technique. Int J Adv Manuf Technol 41:301–310CrossRefGoogle Scholar
- 11.Klocke F, Backer V, Wegner H et al (2009) Influence of process and geometry parameters on the surface layer state after roller burnishing of IN718. Prod Eng Res Dev 3:391–399CrossRefGoogle Scholar
- 12.Franzen V, Trompeter M, Brosius A et al (2010) Finishing of thermally sprayed tool coatings for sheet metal forming operations by roller burnishing. Int J Mater Form 3(1):147–150CrossRefGoogle Scholar
- 13.Aysun S (2011) Analysis and optimization of surface roughness in the ball burnishing process using response surface methodology and desirabilty function. Adv Eng Softw 42:992–998CrossRefGoogle Scholar
- 14.Korzynski M, Lubas J, Swirad S et al (2011) Surface layer characteristics due to slide diamond burnishing with a cylindrical-ended tool. J Mater Process Technol 211:84–94CrossRefGoogle Scholar
- 15.Swirad S (2011) The surface texture analysis after sliding burnishing with cylindrical elements. Wear 271:576–581CrossRefGoogle Scholar
- 16.Tadic B, Todorovic PM, Luzanin O et al (2013) Using specially designed high-stiffness burnishing tool to achieve high-quality surface finish. Int J Adv Manuf Technol 67:601–611CrossRefGoogle Scholar
- 17.Balland P, Tabourot L, Degre F et al (2013) An investigation of the mechanics of roller burnishing through finite element simulation and experiments. Int J Machine Tools Manuf 65:29–36CrossRefGoogle Scholar
- 18.Balland P, Tabourot L, Degre F et al (2013) Mechanics of the burnishing process. Precis Eng 37:129–134CrossRefGoogle Scholar
- 19.Dwivedi SP, Kumar S, Kumar A (2012) Effect of turning parameters on surface roughness of A356/5% SiC composite produced by electromagnetic stir casting. J Mech Sci Technol 26(12):3973–3979CrossRefGoogle Scholar
- 20.Muralidharan R, Ramana GR (2013) Thermal plasma synthesis of SiC. Adv Manuf 1:50–61CrossRefGoogle Scholar
- 21.Rao TB, Gopala Krishna A (2013) Simultaneous optimization of multiple performance characteristics in WEDM for machining ZC63/SiCp MMC. Adv Manuf 1:265–275CrossRefGoogle Scholar
- 22.El-Tayeb NSM, Low KO, Brevern PV (2007) Influence of roller burnishing contact width and burnishing orientation on surface quality and tribological behaviour of Aluminium 6061. J Mater Process Technol 186:272–278CrossRefGoogle Scholar
- 23.Dwivedi SP, Sharma S, Mishra K (2014) Microstructure and mechanical behavior of A356/SiC/Fly-ash hybrid composites produced by electromagnetic stir casting. J Braz Soc Mech Sci Eng 1–11Google Scholar
- 24.Wang G, Rong YM (2013) Advances of physics-based precision modeling and simulation for manufacturing processes. Adv Manuf 1:75–81CrossRefGoogle Scholar
- 25.Chen SL, Cao WS, Zhang F et al (2013) Development of a computational tool for materials design. Adv Manuf 1:123–129CrossRefGoogle Scholar
- 26.Kosaraju S, Anne VG (2013) Optimal machining conditions for turning Ti–6Al–4V using response surface methodology. Adv Manuf 1:329–339CrossRefGoogle Scholar
- 27.Xu Y, Gao F, Zhang B et al (2013) Technology of self-repairing and reinforcement of metal worn surface. Adv Manuf 1:102–105CrossRefGoogle Scholar
- 28.Lu WC, Ji XB, Li MJ et al (2013) Using support vector machine for materials design. Adv Manuf 1:151–159CrossRefGoogle Scholar
- 29.Li FL, Xia W, Zhou ZY et al (2013) Analytical prediction and experimental verification of surface roughness during the burnishing process. Int J Machine Tools Manuf 62:67–75CrossRefGoogle Scholar