Comparison on various machinability aspects between mixed and reinforced ceramics when machining hardened steels (original) (raw)
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Performance of coated and uncoated mixed ceramic tools in hard turning process
Measurement, 2016
The present contribution deals with the study of the effects of cutting speed, feed rate and depth of cut on the performance of machining which traditionally named ''machinability". The focus is made on the effect of the pre-cited cutting parameters on the evolution of surface roughness and cutting force components during hard turning of AISI D3 cold work tool steel with CC6050 and CC650 ceramic inserts. Also, for both ceramics a comparison of their wear evolution with time and its impact on the surface equality was proposed. The planning of experiments was based on Taguchi's L 16 orthogonal array. The analysis of variance (ANOVA), the signal-to-noise ratio and response surface methodology (RSM) were adopted. Consequently, the validity of proposed linear regression model was checked and the most important parameter affecting the surface roughness and cutting force components were determined. Furthermore, in order to determine the levels of the cutting regime that lead to minimum surface roughness and minimum machining force the relationship between cutting factors was analyzed. The results revealed that the surface quality obtained with the coated CC6050 ceramic insert is 1.6 times better than the one obtained with uncoated CC650 ceramic insert. However, the uncoated ceramic insert was useful in reducing the machining force.
Mechanics & Industry, 2015
This paper describes a comparison between mixed ceramic [Al2O3 (70%) + TiC (30%)] and reinforced ceramic [Al2O3 (75%) + SiC (25%)] tools in terms of cutting force components when machining in dry hard turning AISI 4140 steel, hardened to 60 HRC. The response surface methodology (RSM) and the analysis of variance (ANOVA) are applied to investigate effects of cutting speed, feed rate and depth of cut on cutting force components in order to model and optimize these technological parameters. Results of this study indicate that the machining with the mixed ceramic insert generates lower values of cutting force components than reinforced ceramic insert. Consequently, the mixed ceramic CC650 is the most powerful tool. The developed models can be used in the metal machining industries and would be helpful in selecting cutting variables for optimization of hard cutting process.
Journal of Physics: Conference Series, 2019
In the present work, the effects of machining factors and cutting fluid flow conditions on tool wear and surface roughness were studied. Response surface methodology technique with Face centered composite design was employed to minimize the number of experiments. The experiments were performed on a hardened AISI D2 rod using mixed ceramic (Al 2 O 3 /TiC) inserts in turning process. The effect of machining time was found to be the most influential parameter affecting tool wear, followed by cutting speed. However, machining time followed by feed rate were the most significant parameters on surface roughness. Moreover, cutting fluid condition showed substantial contribution towards decreasing tool wear rate and increasing surface finish.
The International Journal of Advanced Manufacturing Technology, 2014
The hard turning process has been attracting interest in different industrial sectors for finishing operations of hard materials. In this paper, the effects of cutting speed, feed rate, and depth of cut on surface roughness, cutting force, specific cutting force, and power in the hard turning were experimentally investigated. An experimental investigation was carried out using ceramic cutting tools, composed approximately with (70 %) of Al 2 O 3 and (30 %) of TiC, in surface finish operations on cold work tool steel AISI D3 heat-treated to a hardness of 60 HRC. Based on 3 3 full factorial designs, a total of 27 tests were carried out. The range of each parameter is set at three different levels, namely, low, medium, and high. Analysis of variance is used to check the validity of the model. Experimental observations show that higher cutting forces are required for machining harder work material. This cutting force gets affected mostly by feed rate followed by depth of cut. Feed rate is the most influencing factor on surface roughness. Feed rate followed by depth of cut become the most influencing factors on power; especially in case of harder workpiece. Optimum cutting conditions are determined using response surface methodology (RSM) and the desirability function approach. It was found that, the use of lower depth of cut value, higher cutting speed, and by limiting the feed rate to 0.12 and 0.13 mm/rev, while hard turning of AISI D3 hardened steel, respectively, ensures minimum cutting forces and better surface roughness. Higher values of depth of cut are necessary to minimize the specific cutting force.
Multidiscipline Modeling in Materials and Structures, 2008
This paper presents a study of the development of surface roughness model when turning the mild steel hardened up to 484 HV with mixed alumina ceramic (KY1615) and coated alumina ceramic cutting tools (KY4400). The model was developed in terms of main cutting parameters such as cutting speed, feed rate and depth of cut, using response surface methodology. The established equation indicated that the feed rate affected the surface roughness the most, but other parametres remined stable for arithmetic average height parametre (Ra). However, it decreased with increasing the cutting speed, and with the starting and finishing point of cut for ten point height parametre (Rz). The cutting speed and the depth of cut had a slight effect on surface roughness values of Ra, Rz when using KY4400 cutting tools. Furthermore, the average surface roughness value of Ra was about 0.926 um, 1.089 um for KY1615, KY4400 cutting tools, respectively. The predicted surface roughness was found to be very clos...
Tehnicki vjesnik - Technical Gazette, 2019
In this study, the performance and the useful life of a mixed ceramic tool with S-type edge microgeometry are evaluated for the case of dry turning of AISI 4140 steel hardened to 55 HRC. The influence of the cutting speed and feed rate of the cutting parameters on the tool failure was investigated. The experiments were designed and analysed using the complete factorial design technique. Our results indicate that the cutting speed and feed rate values exert significant influence on the tool lifespan. Crater and flank wear occur in all cutting conditions. The predominant tool wear mechanisms are diffusion, abrasion, and adhesion, which are also known as attrition. The tool life curve and equation were established for the machining conditions of this investigation to achieve the subsequent optimisation of this process.
Sādhanā
This study investigated the cutting performance of coated CC6050 and uncoated CC650 mixed ceramics in hard turning of hardened steel. The cutting performance was mainly evaluated by cutting force components and tool wear. The planning of experiments was based on Taguchi's L 36 orthogonal array. The response surface methodology and analysis of variance were used to check the validity of multiple linear regression models and to determine the significant parameter affecting the cutting force components. Tool wear progressions and, hence, tool life, different tool wear forms and wear mechanisms observed for tools coated with TiN and uncoated mixed ceramics are presented along with the images captured by digital and electron microscope. Experimental observations indicate higher tool life with uncoated ceramic tools, which shows encouraging potential of these tools to hard turning of AISI H11 (50 HRC). Finally, tool performance indices are based on units which characterise machined cutting force components and wear when hard turning.
International Journal of Precision Engineering and Manufacturing, 2012
Composite Fiber Reinforced Plastics (CFRP) are characterized by their outstanding mechanical properties combined with reduced density and good resistance to corrosion and fatigue which make them suitable for aerospace components. During assembly procedures, one shoot drilling operations, usually including countersinking cycle, are required to minimize positional errors, enhance tight tolerances and reduce process time. Countersink drill bits were tested on CFRP test specimens, representative of aircraft components. Along testing, tool wear was monitored with an optical microscope to track its evolution and determine the dominant wear mechanism. On the other hand, hole quality was evaluated since tool life criterion is based on the assessment of machined surface quality. The influence of cutting speed and feed was analyzed with the objective of looking for extended tool life and more productive cutting parameters. The information gathered from monitoring tool wear and inspecting hole quality can be used for the enhancement of CFRP drilling and the improvement of the manufacturing process competitiveness, in terms of production cost and time.
2018
Wear investigation has been conducted on mixed ceramic cutting tool (70% Al2O3 + 30% TiC) when machining hardened AISI 52100 steel (66 HRC). Experimental planning method has been used to assess the relationship between radial cutting vibrations and surface roughness as a function of the machining conditions. First, wear results show that when the cutting speed is increased 3.78 times, tool life drops of 8.75 times. When increasing the feed rate by a factor of 2.75 tool life decreases by a factor of 1.4. Then, the effect of cutting parameters (speed, feed and depth) on one hand surface roughness (Ra) and in the other hand radial tool vibrations has been determined using the multiple regression models with a coefficient of determination R2 equal to respectively 95.5% and 89.3%. With regards to surface roughness, ANOVA analyses reveal that feed rate contributes of about 84% in the surface roughness. Meanwhile, looking at the vibration phenomena, the cutting speed has the most significa...
Nomenclature a p -depth of cut, mm; f -feed rate, mm/rev; F -resulting cutting force, N; Fa -feed force, N; Fr -thrust force, N ; Fv -tangential cutting force, N ; HRC -Rockwell hardness; R² -coefficient of determination; Ra -arithmetic mean roughness, μm; Rt -total roughness, μm; Rz -mean depth of roughness, μm; r ε -tool nose radius, mm ; VBflank wear, mm ; Vc -cutting speed, m/min ; α -relief angle, degree ; γ -rake angle, degree ; λ -inclination angle, degree ; χ -major cutting edge angle, degree.