The demand for the use of nickel-based superalloy such as Inconel 718 is increasing in aerospace industry as it is efficient for energy and has excellent properties. In this paper, the experimental studies of tool wear mechanism and tool life in ball nose end milling of Inconel 718 is presented under minimum quantity lubricant (MQL) condition. The evaluations of the results are focusing on the comparison of up-milling and down-milling operations using physical vapor deposition (PVD) - coated carbide inserts. Machining parameters; depth of cut, feed rate and cutting speed are considered during the evaluation. The experimental results showed that down-milling operation has better results in terms of tool wear than up-milling operation. Chipping on cutting tool edge was the primary reason that responsible to notch wear with prolong machining

The optimization of surface integrity in drilling process using response surface method (RSM) is presented. This paper investigates the effects of drilling parameter such as spindle speed, feed rate and drill diameter on the surface roughness and surface texture of drilled hole by applying RSM. There are three factors (spindle speed, feed rate and drill diameter) under investigation, therefore, by applying RSM there will be 20 experimental observations. The minimum surface roughness measured for the hole was 1.06μm at combination of 2000rpm spindle speed, 78mm/min feed rate and 2.5mm drill diameter. While the maximum surface roughness of 2.59μm was measured at the combination of 250rpm spindle speed, 153mm/min feed rate and 3.5mm drill diameter. One factor plot analysis found that the most significant parameter was spindle speed followed by drill diameter and feed rate. Thus, surface roughness decreased when increasing the spindle speed, feed rate and drill diameter. There were interactions between all the parameter of spindle speed, feed rate and drill diameter in drilling process under investigation

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