Effects of deep cryogenic treatment on machinability, hardness and microstructure in dry turning process of tempered steels

2020 ◽  
pp. 095440892097944
Author(s):  
Menderes Kam
Keyword(s):  
Cryogenic Treatment ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Point Of View ◽  
Turning Process ◽  
Deep Cryogenic Treatment ◽  
Dry Turning ◽  
Control Factors ◽  
Heat Treated ◽  
Hardness Values

This study investigated the effects of Deep Cryogenic Treatment (DCT) on machinability, hardness, and microstructure in dry turning process of AISI 4140 (48-51 HRc) tempered steels with ceramic cutting tools on the surface roughness (Ra). DCT process of steels has shown significant improvement in their mechanical properties. In this context, experiments were made with Taguchi L16 method and optimum values were determined. Three different values for each control factors as: different heat treated samples, cutting speeds (160, 200, 240, 280 m/min), feed rates (0.08, 0.12, 0.16, 0.20 mm/rev) were selected. As a result, the lowest Ra value was found to be 0.159 µm for the DCTT36 sample at a cutting speed of 240 m/min, a feed rate of 0.08 mm/rev. The optimum Ra value was the lowest for the DCTT36 sample compared to the other samples as 0.206 µm. The hardness values of the micro and macro were highest for the DCTT36 sample. Microstructural point of view Scanning Electron Microscopy (SEM) point of view, the DCCT36 sample showed that best results owing to its homogeneity. It was concluded that lower Ra values can be obtained with ceramic cutting tool in dry turning experiments according to the studies in the literature review. It is thought to be preferred as an alternative to cylindrical grinding process due to lower cost.

Analysis of tool vibration and surface roughness during turning process of tempered steel samples using Taguchi method

2021 ◽  
pp. 095440892110019
Author(s):  
Menderes Kam ◽  
Mustafa Demirtaş
Keyword(s):  
Surface Roughness ◽  
Taguchi Method ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Machining Parameters ◽  
Turning Process ◽  
Machining Time ◽  
Tool Vibration ◽  
Control Factors ◽  
Tempered Steel

This study analyzed the tool vibration (Vib) and surface roughness (Ra) during turning of AISI 4340 (34CrNiMo6) tempered steel samples using Taguchi Method. In this context, Taguchi design L18 (21 × 32) was used to analyze the experimental results. The vibration amplitude values from cutting tools were recorded for different machining parameters, control factors; two different sample hardness (46 and 53 HRc), three different cutting speeds (180, 220, 260 m.min−1), and feed rates (0.08, 0.14, 0.20 mm.rev−1) were selected. The machining parameters giving optimum Vib and Ra values were determined. Regression analysis is applied to predict values of Vib and Ra. Analysis of variance was used to determine the effects of machining parameters on the Vib and Ra values. The most important machining parameters were found to be the feed rate, sample hardness, and cutting speed for Vib and Ra, respectively. The lowest Vib and Ra values were obtained in 46 HRc sample as 0.0022 gRMS and 0.255 µm, respectively. The surface quality can be improved by reducing the sources of vibration by using appropriate machining parameters. As a result, there is a significant relationship between Ra and Vib. The lower Ra values were found during turning process of tempered steel samples according to the literature studies. It is suggested that the process can be preferred as an alternative process to grinding process due to lower cost and machining time. In application of the turning of experiment samples by ceramic cutting tool, a substantial technological and economical benefit has been observed.

Taguchi optimization of surface roughness in the turning of Hastelloy C22 super alloy using cryogenically treated ceramic inserts

2020 ◽  
Vol 234 (19) ◽  
pp. 3826-3836
Author(s):  
Sıtkı Akincioğlu ◽  
Hasan Gökkaya ◽  
Gülşah Akincioğlu ◽  
Meltem A Karataş
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Cryogenic Treatment ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Deep Cryogenic Treatment ◽  
Taguchi Optimization ◽  
Factors Affecting ◽  
Treatment Type ◽  
Super Alloy

Cryogenic treatment has been used in recent years to improve the performance of cutting tools. This study evaluated the machinability of a nickel–molybdenum-based super alloy using cryogenically treated (–80 ℃ and –145 ℃) ceramic inserts under dry turning conditions. Three cutting speeds (350, 400, and 450 m/min), three feed rates (0.1, 0.2, and 0.3 mm/rev), and a 1-mm fixed cutting depth were used in the turning tests. Experiments were conducted using the Taguchi orthogonal array L27 design. The factors affecting the surface roughness (Ra) were determined via analysis of variance. The effect of cryogenic treatment type (shallow and deep), cutting speed, and feed rate on surface roughness was investigated. Results of the analysis determined that the feed rate was the major parameter that affected surface roughness and that the deep cryogenic treatment was more effective. The regression analysis confirmed that the experimental results and the predicted values were within the 95% confidence interval. The most effective parameter affecting the surface roughness was feed rate at a contribution of 57.9%. The contribution of the cutting tool type to the surface roughness was 28.5%. The results obtained showed that the surface roughness can be optimized for turning the Hastelloy c22 super alloy with the Taguchi method.

scholarly journals Cutting performance of deep cryogenic treated and nitrided HSS cutting tool inserts

2019 ◽  
Vol 13 (3) ◽  
pp. 213-217
Author(s):  
Sanja Šolić ◽  
Zdravko Schauperl ◽  
Vlado Tropša
Keyword(s):  
Wear Resistance ◽  
High Speed ◽  
Cutting Tool ◽  
Cryogenic Treatment ◽  
Single Point ◽  
Cutting Tools ◽  
Cutting Speed ◽  
High Speed Steel ◽  
Cutting Performance ◽  
Deep Cryogenic Treatment

High speed steel (HSS) is a very important industrial tool material and has been constantly improved for different wear resistance applications and cutting tools, i.e. drills, milling cutters, hobs and for the cutting tools in which the economical cutting speed is too low for choosing the carbide tools. The properties of HSS depend significantly on the parameters of the conducted heat treatment. In this paper, the influence of deep cryogenic treatment in combination with nitriding of metallurgical powder metallurgy HSS on the wear resistance was measured. Additionally, the cutting performance in a single point cutting tool machinability test at the configuration of the dry low-speed turning of steel was investigated. The results showed that deep cryogenic treatment itself, and in combination with nitriding, resulted in the reduction of the wear rate. The results of the single point cutting tool machinability test showed that deep cryogenic treated and nitrided HSS inserts performed worse than the classically heat-treated inserts and deep cryogenic treated HSS inserts exhibited approximately the same flank wear as the nitrided ones.

scholarly journals Wear evaluation and microstructure analysis of cryogenically treated AISI 440C Bearing steel

2021 ◽  
Author(s):  
Idayan A ◽  
C. Elanchezhian ◽  
B. Vijaya Ramnath ◽  
Palanikumar K
Keyword(s):  
Wear Resistance ◽  
Cryogenic Treatment ◽  
Research Work ◽  
Bearing Steel ◽  
X Ray Diffraction ◽  
Deep Cryogenic Treatment ◽  
X Ray ◽  
Heat Treated ◽  
Increase Wear Resistance ◽  
Wear Evaluation

In this research work, two types of cryogenic treatment such as deep cryogenic treatment (-196oC) and shallow cryogenic treatment (-80oC) have been adopted for wear resistance to increase in AISI 440C bearing steel. This paper has been focused to increase Wear Resistance (WR) through deep micro structural analyses, and also attention has been made to correlate the microstructure with the wear character of Deep Cryogenic treated (DCT) specimens, Conventional Heat Treated (CHT) specimens and Shallow Cryogenic Treated (SCT) specimens. Micro structural examinations have been carried out in the specimens through Scanning Electron Microscopy (SEM), Energy Dispersive Analysis of X-ray (EDAX) and X-Ray Diffraction (XRD). Wear characteristics of AISI 440C bearing steel has been studied. The outcome of the research disclosed that the DCT specimens have higher wear resistance than SCT and CHT specimens. The effective wear mechanisms recognized were the constitution of white layers and delamination of white layers. The microstructures of the materials have been varied through heat treatment process. The modification of Secondary Carbides (SCs) precipitation characteristics and its reduction of retained austenite in the microstructure have been correlated with wear character and these are the liable mechanism to raise the wear resistance of bearing steels through DCT.

Detecting the key geometrical features and grades of carbide inserts for the turning of nickel-based alloys concerning surface integrity

2016 ◽  
Vol 230 (20) ◽  
pp. 3725-3742 ◽  
Author(s):  
A Fernández-Valdivielso ◽  
LN López de Lacalle ◽  
G Urbikain ◽  
A Rodriguez
Keyword(s):  
Surface Integrity ◽  
Inconel 718 ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Rake Angle ◽  
Point Of View ◽  
Basic Operation ◽  
Workpiece Surface ◽  
Common Features ◽  
Feasible Solutions

Machining science is aimed at defining both cutting tools and machining conditions based on economic performance and to maintain workpiece surface integrity. Currently, machinists face a wide offer of turning, milling, drilling, and threading tools. Tools present a lot of similarities and light differences between them, being the latter the concealed reasons for a better or worse performance on difficult-to-cut alloys machining. However machinists had not useful methods for detecting which key tool aspects implies the best performance. The classic and expensive 'test-trial' method results non-viable due to the market exponential increase, both in size and specialization. This paper brings up an indirect method for seeking common features in the group of those tools with the best performance on machining Inconel 718. The method is divided into five stages, namely: (a) raw testing of a basic operation with a lot of commercial solutions for the same operation; (b) filtering of results to reduce the feasible solutions to a few ones, studying the common features of successful cases; (c) testing of these feasible solutions aimed at choosing the best insert or tool (d); and finally (e) full testing concerning all workpiece surface integrity issues. The proposed method provides knowledge based on the distilling of results, identifying carbide grades, chipbreakers shapes, and other features for having the best tool performance. All surface integrity effects are checked for the best solution. This new point of view is the only way for improving the difficult-to-cut alloys machining, reaching technical conclusions with industrial interest. This paper shows the method applied on Inconel 718 turning, resulting in a carbide grade with 10% cobalt, submicron grain size (0.5–0.8 µm) and hardness around 1760 HV, coating TiAlN monolayer with 3.5 µm thickness, chipbreaker giving 19° of rake angle that becomes 13° real one after insert is clamped on toolholder. Cutting edge radius after coating was 48 µm approximately. Cutting speed was 70 m/min higher in comparison with that recommended in handbooks.

Effect of Deep Cryogenic Treatment on the Microstructure of an Aerospace Aluminum Alloy

2012 ◽  
Vol 445 ◽  
pp. 965-970 ◽  
Author(s):  
F. Bouzada ◽  
M. Cabeza ◽  
P. Merino ◽  
S. Trillo
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Grain Boundaries ◽  
Cryogenic Treatment ◽  
Deep Cryogenic Treatment ◽  
Heat Treated ◽  
Static Mechanical ◽  
Compressive Residual Stresses ◽  
Static Mechanical Properties

This paper describes how deep cryogenic treatment at 98K produces changes in the microstructure of a heat-treated aluminum alloy. It was observed how the sub-micrometric particles increased near and at the grain boundaries. This slight precipitation did not produce any modification in static mechanical properties. However, the compressive residual stresses of the material were higher after compared to before the treatment. Both these effects can enhance the life of this alloy through cryogenic treatment.

Improvement of Tool Life of a Commercial Drill Bits by Cryogenic Treatment While Machining Widmanstatten Ti-6Al-4V.

2021 ◽  
Author(s):  
Abdullah Sert ◽  
Fatih Hayati ÇAKIR
Keyword(s):  
Tool Wear ◽  
Tool Life ◽  
Cutting Forces ◽  
Cutting Tool ◽  
Cryogenic Treatment ◽  
Cutting Tools ◽  
Drill Bit ◽  
Deep Cryogenic Treatment ◽  
Drill Bits ◽  
Stereo Microscope

Abstract In this study, the performance of Ø 8 mm WC-Co (10%) drill bits with a TiAlN coating was tested for machining of Ti6Al4V alloy with a Widmanstatten structure. In order to improve the tool life, cutting tools were subjected to deep cryogenic treatment. In total, three groups of tools were prepared for this study. The first group was used for reference as the supplied state; the second group was subjected to 24 hours deep cryogenic treatment at -196 ° C, and the third group was subjected to 24 hours deep cryogenic at -196 ° C, additionally was tempered 2 hours at 200 ° C. Machining experiments were done by drilling and a set of 60 holes were drilled with each drill bit, and tool wear were observed and recorded with a stereo microscope. Additionally, Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) analyses were carried on to understand the tool wear better. The microhardness of Cryo-treated and tempered cutting tools hardness increased up to 20 Hv (about 1%), and the toughness value did not change significantly. Cutting performance was observed by measuring the cutting forces during drilling experiments. According to these results, deep cryogenic treatment on WC-Co-based inserts decreased cutting forces by approximately 7% compared to the reference drill bit, which affected the cutting tool life. The dominant wear mechanism was Built-up edge (BUE) formation, and cryo-treatment lowered the BUE amount 8% and cryo-treated and tempered drill bit 45% compared to the reference drill bit.

Study on the Cutting Properties about Magnesium Alloy when Dry Turning with Kentanium Cutting Tools

2010 ◽  
Vol 102-104 ◽  
pp. 653-657 ◽  
Author(s):  
Xu Hong Guo ◽  
Li Jun Teng ◽  
Wei Wang ◽  
Ting Ting Chen
Keyword(s):  
Surface Roughness ◽  
Magnesium Alloy ◽  
Tool Wear ◽  
Cutting Force ◽  
Feed Rate ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Depth ◽  
Dry Turning ◽  
Main Influence

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.

Prediction of the Cutting Forces on Stainless Steels When Using a Turning Process

2003 ◽  
Author(s):  
Zulay Cassier ◽  
Patricia Mun˜oz-Escalona ◽  
Jannelly Moreno
Keyword(s):  
Stainless Steels ◽  
Cutting Forces ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Machining Process ◽  
Depth Of Cut ◽  
Turning Process ◽  
High Corrosion Resistance ◽  
Aisi 304 ◽  
Heat Treated

Stainless steels have a great application in the manufacturing process especially due to their characteristic high corrosion resistance. The machining of these materials, the study of the cutting forces, and the power required for the cutting are important parameters to be evaluated. Their relationship with other cutting variables process is crucial for the optimization of the machining process. The results of this research are empirical expressions relating cutting parameters (cutting speed, feed rate and depth of cut) to cutting forces for each stainless steel studied, AISI 304, AISI 420 and AISI 420HT (HT: Heat treated). A general expression was also developed which includes the mechanical properties of these stainless steels. These results enable the user to predict cutting forces when using a turning process.

Techanics Experiment Study on PcBN Cutting Tool Dry Turning Austenitic Stainless Steel AISI 304

2011 ◽  
Vol 341-342 ◽  
pp. 256-260
Author(s):  
Yun Hai Jia
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Feed Rate ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Aisi 304 ◽  
Dry Turning ◽  
Steel Aisi ◽  
Cut Depth ◽  
Stainless Steel Aisi

High deformation hardening, low thermal conductivity, high built-up edge tendency of austenitic stainless steels were the main factors that make their machinablity difficult. For determination of the suitable cutting parameters in machining austenitic stainless steel AISI 304 by PcBN cutting tools, the samples which were prepared to be used in the experiment, 300 mm in length and 60 mm in diameter, were dry machined in a numerical control lathe. During experiments, dry turning parameters, such as feed rate, cutting speed and cut depth were investigated. The suitable cutting speed and feed rate were determined according to workpieces surface roughness, cutting tools flank wear. Finally, cutting speed of 180 to 200 m/min, feed rate of 0.05 to 0.06 mm/rev and cut depth of 0.10 mm gave the satisfied results.

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