Papers by Keyword: Tool Wear

Abstract: This paper embarks the machining parameters of Turning by optimization using Taguchi’s approach. The optimization is very essential in order to obtain the expected surface quality. The results of cutting parameters of optimization is seen in the Surface Roughness, Tool wear and MRR of the material. The L18 Orthogonal array has been chosen for the optimization of Valve Steel SUH03.The uncoated carbide inserts were used and the four parameters Speed, Feed, Depth of Cut and Nose Radius has been taken as input parameters. The Signal to Noise ratio and Analysis of Variance software has been analyzed using Minitab software through which the optimal cutting parameters of the best surface roughness, tool wear and MRR has been obtained. The final results have been compared by the Gray relational analysis to find the optimum machining conditions of all the parameters.

Abstract: This research proposed an in-process tool wear prediction during the ball-end milling process by utilizing the cutting force ratio. The dimensionless cutting force ratio is proposed to cut off the effects of the work material and the combination of cutting conditions. The in-process tool wear prediction model is developed by employing the exponential function, which consists of the spindle speed, the feed rate, the depth of cut, the tool diameter, and the cutting force ratio. The experimentally obtained results showed that the cutting force ratio can be utilized to predict the tool wear of ball-end milling tool. The new cutting tests have been employed to verify the model and the results run satisfaction. It has been proved that the in-process tool wear prediction model can be used to predict the tool wear regardless of the cutting conditions with the highly acceptable prediction accuracy.

Abstract: Cutting fluid is a well-known as one of an important element in machining process. However, the consumption of mineral oils as cutting fluid has been raising concern due to worldwide interest in environmental and health matters. The application of vegetable-oil based lubricant is seen can overcome the problem but requires a research study about the machinability. This research paper represents the machinability of using several possible vegetable oils as cutting fluid in term of chip formation and tool wear during drilling operation on stainless steel, AISI 316. In particular, the performance of the vegetable oils; palm, sesame, olive and coconut oils were compared under minimum quantity lubrication (MQL) technique. The result reported that the coconut oil indicates the best machinability in term of highest and uniform chip thickness and least wear on the drill bit under same condition with others. These performances are followed by palm, olive and sesame oil. In additional, the viscosity measurement indicates that coconut oil has the lowest value which can possesses better fluidity and faster cooling capacity than other oils. Overall, coconut oil is recommended as viable alternative lubricants during drilling of stainless steel.

Abstract: An internal cooling system inside a toolholder was developed aiming to eliminate the need of using cutting fluid without compromising machining efficiency. A phase change coolant (R141-b), with boiling point of 32oC around 101.3 kPa (atmosphere pressure), was used to improve heat dissipation in the cutting tool. Turning tests on SAE XEV-F were carried out using coated cemented carbide inserts. The results showed that the cutting tools lives were greater with internally cooled method than in dry cutting conditions. Nevertheless, the results were limited due to the low thermal conductivity of the steel (14.5 W.m/K) that is similar to Inconel^®, its abrasivity, and absence of lubricant effect of the internal cooling method. On the other hand, the cutting tool geometry was not modified as was done in others solutions found in literature and the cooling system operated in a closed loop. It has a great possibility of use by the industry because is an environmentally friendly technology.

Abstract: An aluminum/chromium based coating film, called (Al,Cr)N coating film, has been developed. This coating film has a slightly more inferior critical scratch load and micro-hardness. Therefore, to improve both the scratch strength and micro-hardness of the (Al,Cr)N coating film, the cathode material of an alumi-num/chromium/tungsten target was used in adding the tungsten (W) to the cathode material of the alumi-num/chromium target. To clarify the effectiveness of the aluminum/chromium/tungsten-based coating film, we measured the thickness, micro-hardness and critical scratch strength of aluminum/chromium/tungsten-based coating film formed on the surface of a substrate of cemented carbide ISO K10 formed by the arc ion plating process. The hardened steel ASTM D2 was turned with the (Al,Cr,W)N, (Al,Cr,W)(C,N), (Al,Cr)N and the (Ti,Al)N coated cemented carbide tools. The tool wear of the coated cemented carbide tools was ex-perimentally investigated. The following results were obtained: (1) The micro-hardness of the (Al,Cr,W)N or (Al,Cr,W)(C,N), (Al,Cr)N coating film was 3110 HV_0.25N or 3080 HV_0.25N, respectively. (2) The critical scratch load of the (Al,Cr,W)(C,N) coating film was 123 N, which was much higher than that of the (Al,Cr)N or (Ti,Al)N coating film. (3) In cutting the hardened steel using (Al,Cr,W)(C,N) and (Ti,Al)N coated carbide tools, the wear progress of the (Al,Cr,W)(C,N) coated carbide tool was almost equivalent to that of the (Ti,Al)N coated carbide tool. The above results clarify that the aluminum/chromium/tungsten-based coating film, which is a new type of coating film, has both high hardness and good adhesive strength, and can be used as a coating film of WC-Co cemented carbide cutting tools.

Abstract: This paper aimed to investigate the machining factors influencing surface roughness and to obtain the appropriate turning operation of aluminum. The Shainin design of experiment method was used to investigate the effect of the four turning factors on surface roughness. Moreover, analysis of variance and multiple comparisons were used to obtain the appropriate turning operation of the significant factors. The results showed that spindle speed was the only significant factor affecting the average surface roughness with the appropriate turning operation of 1000 rpm used for reducing surface roughness of the machined part and tool wear.

Abstract: Due to its relatively low mass density, low cost, high strength, the aluminum alloy is an ideal optical material to fabricate the large metal mirror of infrared band optical systems. The diamond ultra-precision cutting can produce ultra smooth machined surfaces without other finishing processes. Consequently, it can be used as a effective method to fabricate the large metal mirror. However, the tool wear is severe during the ultra-precision processes, which will ruduces the surface error of the large metal mirror. In this work, the ultra-precision cutting tests were performed to investigate the tool wear. The tool wear was examined by using a scanning electron microscope (SEM), and the chip was examined by using x-ray energy dispersive spectrdmeter (EDS). The tool wear mechanism and the influence of the chutting parameters on the tool wear were investigated. The results show that the daimond tool occurred abrasive wear and diffusing wear in the diamond ultra-precision cutting of aluminum alloy. The average clearance wear width increases with an increase of the cutting speed and the feed rate. There is a slight rise in the average clearance wear width as the depth of the cut increases in the range of 5μm-15μm. The average clearance wear width obviously increases when the depth of the cut reaches to 20μm.

Abstract: Carbon fiber-reinforced plastics (CFRP) are typical difficult-to-machine materials, which is easy to produce many defects such as burrs, dilacerations, layering in milling process. And selecting the appropriate cutting tool has become the key to machining CFRP with high quality and efficiency. In the paper, the machining principle of milling CFRP with new type end mill was analyzed. The diamond coating of general right-hand end mill, cross-flute router and fine-cross-nick router were used to cutting CFRP under the same cutting condition. Through the comparative analysis of the workpiece’s surface quality and tool wear, it concluded that: compared with right-hand diamond coated end mill, cross-flute diamond coated router or fine-cross-nick diamond coated router could effectively suppress the appearance of burrs and dilacerations; abnormal coating peeling appeared in the flank face of right-hand diamond coated end mill, forming the boundary wear, which accelerated wear failure; the flank wear of diamond coated cross-flute router and fine-cross-nick router were both abrasive wear. Due to having more cutting edge than cross-flute router in cutting process, the flank wear of fine-cross-nick router was slower, and the tool life was longer. So it was more suitable for cutting CFRP.

Abstract: This paper presents workpiece surface integrity of micromilling hardened tool steel AISI D2. These include 3D mapping of surface texture, analysis of microstructure and microhardness variation. The results indicate no evidence of major surface damage such as microcracks, un-tempered/over-tempered martensite, phase transformations or white layer formation was detected in any of the specimens analysed. No discernible deformation of the material grain structure beneath the machined surface was observed. This was mainly attributed to the comparatively low levels of mechanical force and temperatures generated during the micro milling operation.

Abstract: Metal matrix composites (MMC) are the combination of base metal matrix and reinforcing materials like SiC, Al₂O₃, etc. The present research is focused on the machinability studies of Al 6061 reinforced with 10% wtof Al₂O₃ particles using multi layered coated carbide inserts. Fabricated samples by stir casting route were turned by the most variable factors, cutting speed, depth of cutand by a constant feed rate of 0.206 mm/rev. Surface roughness and tool wear are considered asoutput. Experiments are conducted by varying the cutting speed while keeping feed rate and depth of cut as constant. After the optimum cutting speed was determined, the depth of cut is varied by keeping the cutting speedand feed rateas constant.Based on the optimum cutting speed (150 m/min), depth of cut (1.2 mm) and feed rate (0.206 mm/rev), a long run test was carried out to find out the tool life and surface finish. But due to the softness nature built up edge formation is obtained. At the optimal parametric combination, the built up edge obtained is less than 2 mm for a machining time of 425 s