Polyetheretherketones (PEEK) have been increasingly employed as biomaterials for trauma, orthoped... more Polyetheretherketones (PEEK) have been increasingly employed as biomaterials for trauma, orthopedic, and spinal implants. These implants are commonly fabricated by extrusion and injection molding, and for this fact, additional machining operations are required. Surface roughness is a vital factor for medical implants since the cells of the surrounding tissue interact with the underlying substrate on the micro and nanometer scales. For some application, such as self-mating articulation cervical disc implants smooth surface finish is critical so as to minimize the contact friction and wear. The requirement for a fine surface roughness poses a major concern in machining of polymeric base materials due to its low thermal conductivity. Machining performance such as surface roughness is directly affected by the milling parameter and should be methodically analyzed. Thus, this paper aims to study the effect of milling parameter on surface roughness of PEEK plastic under dry machining condition. Response Surface Methodology (RSM) technique was used to evaluate the influence of milling parameter namely cutting speed, feed rate and depth of cut on machined surface. From the conducted study, based on the statistical analysis result it is found that feed rate is the main factor that influence the surface roughness followed by milling speed and depth of cut. In addition, optical observation on the machined surface indicated that the mechanisms of the surface finish obtained from machining of polymeric based composites are different from those obtained from machining of the metals. It shows that there is some form of polymeric softening taking place when the cutting speed exceeded a critical cutting speed.
The paper presents a studyof the effect of operating variable parameter; cutting speed, feed rate... more The paper presents a studyof the effect of operating variable parameter; cutting speed, feed rate, depth of cut and width of cut on heat being generated when end milling under MQL condition. The response surface methodology (RSM) was employed in the experiment, and a Box–Behnken design was used to determine the cause and effect of the relationship between the input variables and response. The investigated milling parameters were cutting speed (100 - 140 m/min), feed rate (0.1 - 0.2 mm/tooth), depth of cut (0.5-1.0 mm) and width of cut (0.2 -1.8 mm). Result of this study show ball nose end milling generates low temperature ranging from 69°C to 359°C. Experimental data and statistical analysis showed that heat generation was dominated by radial depth of cut, followed by axial depth of cut. Feed rate and cutting speed were found statistically not significant. The linear models were developed with a 92% confidence level. The optimum condition required for minimum heat generated include cutting speed of 117 m/min, feed rate of 0.11 mm/rev, axial depth of cut of 0.57 mm, and radial depth of cut of 0.21 mm. With this optimum condition, a minimum heat generated of 68°C was obtained.
Polyetheretherketones (PEEK) have been increasingly employed as biomaterials for trauma, orthoped... more Polyetheretherketones (PEEK) have been increasingly employed as biomaterials for trauma, orthopedic, and spinal implants. These implants are commonly fabricated by extrusion and injection molding, and for this fact, additional machining operations are required. Surface roughness is a vital factor for medical implants since the cells of the surrounding tissue interact with the underlying substrate on the micro and nanometer scales. For some application, such as self-mating articulation cervical disc implants smooth surface finish is critical so as to minimize the contact friction and wear. The requirement for a fine surface roughness poses a major concern in machining of polymeric base materials due to its low thermal conductivity. Machining performance such as surface roughness is directly affected by the milling parameter and should be methodically analyzed. Thus, this paper aims to study the effect of milling parameter on surface roughness of PEEK plastic under dry machining condition. Response Surface Methodology (RSM) technique was used to evaluate the influence of milling parameter namely cutting speed, feed rate and depth of cut on machined surface. From the conducted study, based on the statistical analysis result it is found that feed rate is the main factor that influence the surface roughness followed by milling speed and depth of cut. In addition, optical observation on the machined surface indicated that the mechanisms of the surface finish obtained from machining of polymeric based composites are different from those obtained from machining of the metals. It shows that there is some form of polymeric softening taking place when the cutting speed exceeded a critical cutting speed.
The paper presents a studyof the effect of operating variable parameter; cutting speed, feed rate... more The paper presents a studyof the effect of operating variable parameter; cutting speed, feed rate, depth of cut and width of cut on heat being generated when end milling under MQL condition. The response surface methodology (RSM) was employed in the experiment, and a Box–Behnken design was used to determine the cause and effect of the relationship between the input variables and response. The investigated milling parameters were cutting speed (100 - 140 m/min), feed rate (0.1 - 0.2 mm/tooth), depth of cut (0.5-1.0 mm) and width of cut (0.2 -1.8 mm). Result of this study show ball nose end milling generates low temperature ranging from 69°C to 359°C. Experimental data and statistical analysis showed that heat generation was dominated by radial depth of cut, followed by axial depth of cut. Feed rate and cutting speed were found statistically not significant. The linear models were developed with a 92% confidence level. The optimum condition required for minimum heat generated include cutting speed of 117 m/min, feed rate of 0.11 mm/rev, axial depth of cut of 0.57 mm, and radial depth of cut of 0.21 mm. With this optimum condition, a minimum heat generated of 68°C was obtained.
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