scholarly journals Comparison on various machinability aspects between mixed and reinforced ceramics when machining hardened steels

2019 ◽  
Vol 20 (1) ◽  
pp. 109 ◽  
Author(s):  
Hamdi Aouici ◽  
Mohamed Elbah ◽  
Asma Benkhelladi ◽  
Brahim Fnides ◽  
Lakhdar Boulanouar ◽  
...  

The hard turning process has an attracting interest in different industrial sectors for finishing operations of hard materials. However, it still presents disadvantages with respect to process capability and reliability. This paper describes a comparison of surface roughness, specific cutting force and flank wear between mixed ceramic CC650 (Al2O3 (70%) + TiC (30%)) and reinforced ceramic CC670 (Al2O3 (75%) + SiC (25%)) cutting tools when machining in dry hard turning of AISI 4140, treated at 52 HRC using the response surface methodology (RSM). A mathematical prediction model of the machining responses has been developed in terms of cutting speed, feed rate and cutting time parameters. Experimental observations show that the surface roughness obtained with the mixed ceramic insert significantly improved when compared with reinforced ceramic insert with a ratio of 1.44. In the same way, insert CC650 has better performance compared to reinforced ceramic inserts CC670, in terms of the specific cutting force and flank wear.

2013 ◽  
Vol 315 ◽  
pp. 241-245 ◽  
Author(s):  
Ali Davoudinejad ◽  
M.Y. Noordin ◽  
Danial Ghodsiyeh ◽  
Sina Alizadeh Ashrafi ◽  
Mohsen Marani Barzani

Hard turning is a dominant machining operation performed on hardened materials using single-point cutting tools. In recent years, hard turning operation has become more and more capable with respect to various machinability criteria. This work deals with machinability of hardened DF-3 tool steel with 55 ±1 HRC hardness at various cutting conditions in terms of tool life, tool wear mechanism and surface roughness. Continuous dry turning tests were carried out using coated, mixed ceramic insert with honed edge geometry. Two different cutting speeds, 100 and 210 m/min, and feed rate values of 0.05, 0.125 and 0.2 mm/rev were used with a 0.2 mm constant depth of cut for all tests. Additionally scanning electron microscope (SEM) was employed to clarify the different types of wear. As far as tool life was concerned, best result was achieved at lowest cutting condition whereas surface roughness values decreased when operating at higher cutting speed and lower feed rate. Additionally maximum volume of material removed is obtained at low cutting speed and high feed rate. Dominant wear mechanism observed during the experiments were flank and crater wear which is mainly caused by abrasive action of the hard workpiece material with the ceramic cutting tools.


2018 ◽  
Vol 142 ◽  
pp. 03002
Author(s):  
Yunhai Jia ◽  
Lixin Zhu

Ti-6Al-4V components are the most widely used titanium alloy products not only in the aerospace industry, but also for bio-medical applications. The machine-ability of titanium alloys is impaired by their high temperature chemical reactivity, low thermal conductivity and low modulus of elasticity. Polycrystalline cubic boron nitride represents a substitute tool material for turning titanium alloys due to its high hardness, wear resistance, thermal stability and hot red hardness. For determination of suitable cutting parameters in dry turning Ti-6AL-4V alloy by Polycrystalline cubic boron nitride cutting tools, the samples, 300mm in length and 100mm in diameter, were dry machined in a lathe. The turning suitable parameters, such as cutting speed, feed rate and cut depth were determined according to workpieces surface roughness and tools flank wear based on orthogonal experimental design. The experiment showed that the cutting speed in the range of 160~180 m/min, the feed rate is 0.15 mm/rev and the depth of cut is 0.20mm, ideal workpiece surface roughness and little cutting tools flank wear can be obtained.


Author(s):  
Arumugam Mahamani

Machinability of the composites and achieving the dimensional accuracy in addition to surface finish at an economic machining rate is still the topic for numerous researchers. The current article describes the variation in machinability characteristics of AA6061-AlN composites under various sizes of reinforcements. Cutting speed, cutting depth and feed rate are preferred to perform the turning test. Cutting force, surface roughness and flank wear are identified to appraise the machinability characteristics. For an identical machining condition, the nano particle reinforced composite has less surface roughness and minimal flank wear and a greater cutting force than the other composites. An increment in cutting speed raises the flank wear and declines the surface roughness and cutting force for all composites. The findings from the experimental investigation help to utilize the turning process for machining the composites with various sizes of reinforcement at the economic rate of machining without compromising the surface quality.


Author(s):  
Chetan Darshan ◽  
Lakhvir Singh ◽  
APS Sethi

Manufacturers around the globe persistently looking for the cheapest and quality manufactured machined components to compete in the market. Good surface quality is desired for the proper functioning of the produced parts. The surface quality is influenced by cutting speed, feed rate and depth of cut and many other parameters. In the present study attempt has been made to evaluate the performance of ceramic inserts during hard turning of EN-31 steel. The analysis of variance is applied to study the effect of cutting speed, feed rate and depth of cut on Flank wear and surface roughness. Model is found to be statically significant using regression model, while feed and depth of cut are the factor affecting Flank wear and feed is dominating factors for surface roughness. The analysis of variance was used to analyze the input parameters and there interactions during machining. The developed model predicted response factor at 95% confidence level.


2019 ◽  
Vol 18 (04) ◽  
pp. 625-655 ◽  
Author(s):  
Asutosh Panda ◽  
Sudhansu Ranjan Das ◽  
Debabrata Dhupal

The present study addresses the machinability investigation in finish dry hard turning of high strength low alloy steel with coated ceramic tool by considering cutting speed, feed and depth of cut as machining parameters. The technological parameters like surface roughness, flank wear, chip morphology and economical feasibility have been considered to investigate the machinability performances. Twenty seven set of trials according to full factorial design of experiments are performed and analysis of variance, multiple regression method, Taguchi method, desirability function approach and finally Gilbert’s approach are subsequently applied for parametric influence study, mathematical modeling, multi-response optimization, tool life estimation and economic analysis. Results indicated that feed and cutting speed are the most significant controlled as well as dominant factors for hard turning operation if the minimization of the machined surface roughness and tool flank wear is considered. Abrasions, adhesion followed by plastic deformation have been observed to be the principal wear mechanism for tool life estimation and observed tool life for coated ceramic insert is 47[Formula: see text]min under optimum cutting conditions. The total machining cost per part is ensued to be lower ($0.29 only) as a consequence of higher tool life, reduction in downtime and enhancement in savings, which finds economical benefits in hard turning. The current work demonstrates the substitution of conventional, expensive and slow cylindrical grinding process, and proposes the most expensive CBN tool alternative using coated ceramic tools in hard turning process considering techno-economical and ecological aspects.


Author(s):  
Abdullah Altin

In this research, we had studied the sensitivity for machining of cobalt-based superalloy Haynes 188 with ceramic cutting tool. The investigation had focused on the effects of the cutting speed, on the cutting forces, and on the surface roughness based on Taguchi’s experimental design. The effects of machining parameters were determined using Taguchi’s L27 orthogonal array. The signal-to-noise ratio was calculated for the average of surface roughness and the cutting forces, and the smaller were used to determine the optimal cutting conditions. The analysis of variance and the signal-to-noise ratio had effects on the parameters on both surface roughness and cutting. Three different types of cutting tools had been used in the experiment, namely KYON 4300, KYS 25, and KYS 30. The cutting force of Fz was considered to be the main cutting force. Depending on the material which had been used as cutting tool, the Fz had the lowest cutting speed and the lowest surface roughness with the KYS25 ceramic tool. The cutting force and the surface roughness of KYON 4300 cutting tool had shown better performance than other cutting tools. The flank wear and notch were found to be more effective in the experiments. The long chips were removed at low and medium cutting speeds, while the sawdust with one edge and narrow pitch at high cutting speeds was obtained.


2010 ◽  
Vol 102-104 ◽  
pp. 653-657 ◽  
Author(s):  
Xu Hong Guo ◽  
Li Jun Teng ◽  
Wei Wang ◽  
Ting Ting Chen

In recent years, the machinability of magnesium alloy is concerned more and more by the public. In this paper, a study on the cutting properties of magnesium alloy AZ91D when dry turning with kentanium cutting tools is presented. It shows the cutting force measured by a data acquisition system which is made up of Kistler9257B piezoelectric crystal sensor dynamometer, Kistler5070A10100 charge amplifier and computer. The effect of cutting parameters on cutting force was studied, and the experimental formula was built. The tool wear and chip characteristics were observed with KYKY-EM3200 electron scanning microscope and EDAX PV9900 alpha ray spectrometer, while the surface roughness of the workpiece was measured with 2205 profilometer. Results showed that the cutting depth was the main influence factor on cutting force, followed by feed rate and cutting speed . The main form of tool wear showed to be diffusive wear and adhesive wear. The feed rate had the main influence on chip form and the workpiece surface roughness, cutting speed was less effective, the cutting depth was the least.


2018 ◽  
Vol 779 ◽  
pp. 153-158
Author(s):  
Phacharadit Paengchit ◽  
Charnnarong Saikaew

This work investigated the influences of cutting speed and feed rate on surface roughness in hard turning of AISI 4140 chromium molybdenum steel bar using mixed ceramic inserts Al2O3+TiC under dry condition for automotive industry applications. Turning experiments were conducted by varying cutting speed ranging from 150 to 220 m/min and feed rate ranging from 0.06 to 1 mm/rev. General factorial design was used to analyze the data set of surface roughness and determine statistically significant process factors based on analysis of variance results. The results showed that average surface roughness was significantly affected by feed rate and interaction between cutting speed and feed rate at the level of significance of 0.05. An optimal operating condition for hard turning of AISI 4140 with the ceramic cutting tool that produced a minimum machined surface roughness was obtained at cutting speed of 220 m/min and 0.06 mm/rev.


Author(s):  
J S Dureja ◽  
V K Gupta ◽  
V S Sharma ◽  
M Dogra

The present study aims to investigate the wear mechanisms of a TiN-coated mixed ceramic tool prevalent under different machining conditions during hard turning of hot tool die steel. The different wear mechanisms observed are abrasion wear at low cutting speed, low feed rate, and highest work piece hardness; formation of protective layer and built-up edge (BUE) resulting from tribochemical reactions between constituents of tool and work piece material at moderate speed. High temperature accompanied by high cutting speed resulted in the removal of the protective layer and suppressed the BUE formation. Hard carbide particles of work material at a higher feed rate severely gouged the tool flank land. Chipping and brittle fractures were observed at very low and high depth of cut. Adhesion of work piece material followed by plastic deformation and notching was clearly visible at low work piece hardness. The influence of cutting speed, feed rate, depth of cut, and work piece hardness on the progressive tool flank wear, and flank wear rate (VBr-μm/km) in the steady wear region was also analysed.


2014 ◽  
Vol 474 ◽  
pp. 333-338
Author(s):  
János Kundrák ◽  
László Ráczkövi ◽  
Károly Gyáni

This article presents the examination of cutting performance of a low CBN content cutting tool in the case of hard turning of 100Cr6 hardened bearing steel. One of the indicators of cutting performance is the wear rate, which can be calculated as a ratio of a measurable geometric parameter of a wear form and some technological parameters (cutting time, cutting length or removed material volume). The wear of CBN cutting tools is characterized by the extent of flank wear hence the wear rates related to cutting time and removed material volume are calculated based on the measured flank wear during the cutting experiments. The alteration of wear rates as a function of flank wear and cutting speed was examined.


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