Study on High Speed Milling of Steam Turbine Blade Materials - Differences in Cutting Characteristics of Titanium Alloy and Stainless Steel

2016 ◽  
Vol 874 ◽  
pp. 445-449
Author(s):  
Tomonori Kimura ◽  
Tatsuyuki Kamijo ◽  
Takekazu Sawa
Keyword(s):  
Stainless Steel ◽  
Titanium Alloy ◽  
Heat Resistance ◽  
Steam Turbine ◽  
High Speed ◽  
Cutting Speed ◽  
High Speed Milling ◽  
Point Temperature ◽  
Steam Turbine Blade ◽  
Cutting Point

Titanium alloy and stainless steel are used as steam turbine blade materials. However, their machining efficiency is low because they are difficult-to-cut materials. In particular, the high cutting point temperature and short tool life are major problems. Highspeed milling can reduce the cutting point temperature and tool wear. In this study, highspeed milling of a titanium alloy and stainless steel was investigated for the high-efficiency cutting of a steam turbine blade. In the experiment, workpieces were made of titanium alloy Ti-6Al-4V and stainless steel 13Cr. The experiment was conducted at cutting speeds from 100 m/min to 600 m/min. The flank wear increased rapidly with increase in the cutting speed. The loss of the coating on the flank of the end mill was confirmed via energy-dispersive Xray spectroscopy analysis. It was demonstrated that the cutting point temperature was higher than the heat resistance temperature of the coating. The cutting point temperature was analyzed using AdvantEdge FEM. It was found that the cutting point temperature at a cutting speed of 350 m/min or more was higher than the heat resistance temperature of the coating. On the other hand, in the case of the stainless steel 13Cr, the flank wear increased in proportion to the cutting speed, and the loss of the coating on the flank of the end mill was also confirmed. However, the loss of the coating was less than that in the case of the titanium alloy. It was found that the high-speed milling of the stainless steel did not reach the heat resistance temperature of the coating. The cutting characteristics of the high-speed milling of the titanium alloy and stainless steel differed, which was mainly attributed to the difference in the thermal conductivity. In the high-speed milling of the titanium alloy Ti-6Al-4V and stainless steel 13Cr, it was not possible to determine the factors that result in a low cutting point temperature. If the cutting point temperature is lower than the heat resistance temperature of the coating, high-speed milling may be possible. Therefore, the ways in which the cutting point temperature can be lowered will be examined in the future.

Study on High Speed Milling of Steam Turbine Blade Materials

2016 ◽  
Vol 1136 ◽  
pp. 251-256
Author(s):  
Tomonori Kimura ◽  
Takekazu Sawa ◽  
Tatsuyuki Kamijyo
Keyword(s):  
Stainless Steel ◽  
Titanium Alloy ◽  
Steam Turbine ◽  
Turbine Blade ◽  
Tool Life ◽  
High Speed ◽  
Cutting Speed ◽  
High Speed Milling ◽  
Steam Turbine Blade ◽  
Cutting Point

A titanium alloy and stainless steel is an excellent material having properties such as high intensity and high corrosion resistance. Therefore, a titanium alloy and a stainless steel are used as material of steam turbine blade. However, the machining efficiency of a titanium alloy and a stainless steel is a low because of difficult-to-cut materials. Especially, it is a major problem that the cutting point temperature is high and the tool life is short. In the conventional study, it is reported that the cutting point temperature is low and the tool life becomes long by cutting at the suitable cutting speed corresponding to material characteristics. This concept is known as high speed milling. In recent years, the high speed milling is actually used for the metal mold machining. In this study, the high speed milling of the titanium alloy and the stainless steel was tried for the purpose of high efficiency cutting of a steam turbine blade. In the experiment, the cutting tool used the TiAlN coating radius solid end mill made of micro grain cemented carbide. The diameter of endmill is 5mm. The corner radius is 0.2mm. And, the work piece is the titanium alloy Ti-6Al-4V and stainless steel 13Cr. The cutting speed carried out at 100m/min~600m/min. As the result, when the tool life and the surface roughness was a valuation basis, the optimum cutting speed of titanium alloy was 300m/min. On the other hand, In the case of the stainless steel, the flank wear becomes large in proportion to cutting speed. The feature of high speed milling was not able to be confirmed in the range of this experimental condition.

Study on High Speed Milling of Steam Turbine Blade Materials - Difference in Cutting Characteristics by Alloying Elements of Stainless Steel

2016 ◽  
Vol 874 ◽  
pp. 439-444
Author(s):  
Tomonori Kimura ◽  
Takekazu Sawa ◽  
Tatsuyuki Kamijyo
Keyword(s):  
Stainless Steel ◽  
Steam Turbine ◽  
Tool Life ◽  
High Speed ◽  
Cutting Speed ◽  
End Mill ◽  
High Speed Milling ◽  
Point Temperature ◽  
Steam Turbine Blade ◽  
Cutting Point

In this study, high speed milling of stainless steel was tried for purpose of high efficiency cutting of a steam turbine blade. In the experiment, cutting tool used TiAlN coating radius solid end mill made of cemented carbide. Diameter of end mill is 5mm. Corner radius is 0.2mm. Cutting speed carried out at 100m/s~600m/s. Work pieces was used in the experiment are four kinds of stainless steel which alloy elements differ. Mainly, content of chromium and nickel is different. There are many researches about high speed milling [1, 2].However, the researches which examined relationship between alloy elements of stainless steel and cutting characteristics on high speed milling using small diameter endmill are few.As the results, in the case of stainless steel containing much nickel, tool life becomes short in high speed cutting area. This reason is nickel has low thermal conductivity. Because the cutting point temperature becomes higher. If the coating removes, wear becomes large rapidly. In other words, maximum limit value of cutting speed was found to be dependent on heat resistance temperature of the coating.On the other hand, Chromium has the effect of improving the abrasion resistant of the workpiece. However, Flank wear was not increased in a low cutting speed area. In the range of this experimental condition, chromium didn't influence tool life. When cutting point temperature is below heat resistant temperature of the coating, it is thought that effect of the coating is maintained. Namely, it was found that appropriate cutting speed followed heat resistant temperature of the coating.

Study on High-Speed Milling of Steam Turbine Blade Materials - Differences in Cutting Characteristics of an Unforged Ingot and a Forged Part of Stainless Steel

2017 ◽  
Vol 749 ◽  
pp. 3-8
Author(s):  
Tomonori Kimura ◽  
Takekazu Sawa ◽  
Tatsuyuki Kamijyo
Keyword(s):  
Stainless Steel ◽  
Tool Wear ◽  
Steam Turbine ◽  
High Speed ◽  
Flank Wear ◽  
Turbine Blades ◽  
Cutting Speed ◽  
High Speed Milling ◽  
Finished Surface ◽  
Steam Turbine Blade

Stainless steel is an excellent material that has properties such as heat and corrosion resistance. Thus, stainless steel is used as a material in steam turbine blades. Steam turbine blades are mainly manufactured using two methods. One is the cutting of unforged metal ingots. Another is the cutting of forged parts. Small blades are made by cutting metal ingots. Large blades are made by cutting forged parts. The mechanical characteristics of a metal ingot and a forged part, such as hardness and toughness, are almost the same. There were not researches related to a relationship between “an unforged ingot and a forged part of stainless steel” and “the differences of the tool wear and the finished surface by high-speed milling”.In this study, the high-speed milling of stainless steel was attempted for high-efficiency cutting of a steam turbine blade. The differences of the tool wear and the finished surface in the cuttings of an unforged ingot and a forged part were investigated. In the experiment, the cutting tool was a TiAlN coating radius solid end mill made of cemented carbide. The diameter of the end mill was 5 mm, and the corner radius was 0.2 mm. The cutting speed were 100 m/min-600 m/min. The workpieces used were a metal ingot and a forged part of stainless steel. In the results, it was found that the differences of the tool wear and the finished surface in the cuttings of an unforged ingot and a forged part. In the case of the unforged ingot, the flank wear became large with increasing cutting speed. On the other hand, in the case of forged part, the flank wear rapidly increased at a cutting speed of 100 m/min. In addition, the flank wear became smaller than the cutting speed 100 m/min at the cutting speed 200 m/min. Further, the flank wear became large with increasing cutting speed at cutting speeds higher than 200 m/min. That is, the flank wear was at a minimum at a cutting speed of 200 m/min. Although it could not be confirmed the characteristic of high speed milling at an unforged ingot, it has been identified at a forged part.

High Speed Milling of Titanium Alloy

2011 ◽  
Vol 325 ◽  
pp. 387-392 ◽  
Author(s):  
Junsuke Fujiwara ◽  
Takaaki Arimoto ◽  
Kazuya Tanaka
Keyword(s):  
Titanium Alloy ◽  
Tool Wear ◽  
High Speed ◽  
Elevated Temperatures ◽  
Cutting Speed ◽  
Cemented Carbide ◽  
Carbide Tool ◽  
High Speed Milling ◽  
Cemented Carbide Tool ◽  
Coated Cemented Carbide

Titanium alloys have high strength to weight ratio, corrosion resistance, retention of strength at elevated temperatures and low thermal conductivity. In cutting of the titanium alloy, these characteristics have bad influence on tool wear. Therefore, the titanium alloy is generally machined in the milling at low cutting speed. Recently, the demand of the titanium industrial products is increasing and the high speed milling of the titanium alloy is desired. In this study, the Ti-6Al-4V alloy was machined at high cutting speed, and the tool wear progress and the cutting mechanics were experimentally investigated in order to clarify an effective tool material and cooling method for the cutting of the titanium alloy. The results obtained are as follows: In the cutting with a cemented carbide tool and coated cemented carbide tools of TiAlN, TiCN, DLC at the cutting speed 200 m/min, the wear progress of the coated tools were slower than that of the cemented carbide tool. The titanium alloy was cut in the dry and mist methods in order to avoid the thermal effect of the inserts, the wear progress in mist cutting was longer than that in dry cutting.

Cutting Temperature and Cutting Forces Investigation Based on the Taguchi Design Method when High-Speed Milling of Titanium Matrix Composites with PCD Tool

2016 ◽  
Vol 836-837 ◽  
pp. 168-174 ◽  
Author(s):  
Ying Fei Ge ◽  
Hai Xiang Huan ◽  
Jiu Hua Xu
Keyword(s):  
Cutting Force ◽  
Feed Rate ◽  
Cutting Forces ◽  
High Speed ◽  
Volume Fraction ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
High Speed Milling ◽  
Radial Depth

High-speed milling tests were performed on vol. (5%-8%) TiCp/TC4 composite in the speed range of 50-250 m/min using PCD tools to nvestigate the cutting temperature and the cutting forces. The results showed that radial depth of cut and cutting speed were the two significant influences that affected the cutting forces based on the Taguchi prediction. Increasing radial depth of cut and feed rate will increase the cutting force while increasing cutting speed will decrease the cutting force. Cutting force increased less than 5% when the reinforcement volume fraction in the composites increased from 0% to 8%. Radial depth of cut was the only significant influence factor on the cutting temperature. Cutting temperature increased with the increasing radial depth of cut, feed rate or cutting speed. The cutting temperature for the titanium composites was 40-90 °C higher than that for the TC4 matrix. However, the cutting temperature decreased by 4% when the reinforcement's volume fraction increased from 5% to 8%.

Effects of Cutting Parameters on Residual Stresses in High-Speed Milling of Ti-17

2013 ◽  
Vol 834-836 ◽  
pp. 861-865 ◽  
Author(s):  
Yong Shou Liang ◽  
Jun Xue Ren ◽  
Yuan Feng Luo ◽  
Ding Hua Zhang
Keyword(s):  
Experimental Study ◽  
Residual Stresses ◽  
High Speed ◽  
Experimental Parameter ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Single Factor ◽  
Cutting Depth ◽  
High Speed Milling ◽  
Parameter Ranges

An experimental study was conducted to determine cutting parameters of high-speed milling of Ti-17 according to their effects on residual stresses. First, three groups of single factor experiments were carried out to reveal the effects of cutting parameters on residual stresses. Then sensitivity models were established to evaluate the influence degrees of cutting parameters on residual stresses. After that, three criteria were proposed to determine cutting parameters from experimental parameter ranges. In the experiments, the cutting parameter ranges are recommended as [371.8, 406.8] m/min, [0.363, 0.412] mm and [0, 0.018] mm/z for cutting speed, cutting depth and feed per tooth, respectively.

Discrete Element Simulation of the Stress Wave in High Speed Milling

2017 ◽  
Author(s):  
Yifei Jiang ◽  
Jun Zhang ◽  
Yong He ◽  
Hongguang Liu ◽  
Afaque Rafique Memon ◽  
...  
Keyword(s):  
High Speed ◽  
Cutting Tool ◽  
Cutting Speed ◽  
Discrete Element ◽  
Rake Angle ◽  
Stress Waves ◽  
High Speed Milling ◽  
Element Simulation ◽  
Chip Size ◽  
Distribution Of Stress

As cutting tool penetrates into workpiece, stress waves is induced and propagates in the workpiece. This paper aims to propose a two-dimensional discrete element method to analyze the stress waves effects during high speed milling. The dependence of the stress waves propagation characteristics on rake angle and cutting speed was studied. The simulation results show that the energy distribution of stress waves is more concentrated near the tool tip as the rake angle or the cutting speed increases. In addition, the density of initial cracks in the workpiece near the cutting tool increases when the cutting speed is higher. The high speed milling experiments indicate that the chip size decreases as the cutting speed increases, which is just qualitatively consistent with the simulation.

Optimization of High Speed Milling Cutter Based on Critical Cutting Speed

2008 ◽  
Vol 392-394 ◽  
pp. 793-797
Author(s):  
Bin Jiang ◽  
Min Li Zheng ◽  
Fang Xu
Keyword(s):  
High Speed ◽  
Influencing Factor ◽  
Cutting Speed ◽  
Optimization Method ◽  
Face Milling ◽  
Cutting Performance ◽  
Feed Speed ◽  
Milling Cutter ◽  
High Speed Milling ◽  
Cutting Heat

Based on analyses of cutting heat and temperature in high speed milling, to construct a model of critical cutting speed for high speed milling cutter, find out influencing factor of critical cutting speed, and put forward optimization method of high speed milling cutter based on critical cutting speed. The results indicate that chip conducts a majority of cutting heat along with increase of cutting speed, feed speed and the rake of cutter. Cutting heat which workpiece conducts gradually diminishes when heat source accelerates. When cutting performance of cutter satisfies requirements of high speed milling, the proportion of cutting heat which workpiece conducts approaches its maximum as cutting speed comes to critical cutting speed. To optimize high speed face milling cutter for machining aluminum alloy according to critical cutting speed, the cutter takes on better cutting performance when cutting speed is 2040m/min~2350m/min.

scholarly journals Experimental study on machining deformation of large scale slender beam with weak stiffness  of Ti6Al4V

2021 ◽  
Author(s):  
Qimeng Liu ◽  
Jinkai Xu ◽  
Huadong Yu
Keyword(s):  
Titanium Alloy ◽  
Tool Wear ◽  
High Speed ◽  
Large Scale ◽  
Machining Accuracy ◽  
Beam Structure ◽  
High Speed Milling ◽  
Deformation Problem ◽  
Machining Deformation ◽  
Slender Beams

Abstract Large-scale slender beam structures with weak stiffness are widely used in the aviation field. There will be a great deformation problem in machining because the overall stiffness of slender beam parts is lower. Firstly, the cutting mechanism and stability theory of the Ti6Al4V material are analyzed, and then the auxiliary support is carried out according to the machining characteristics of the slender beam structure. The feasibility of the deformation suppression measures for the slender beam is verified by experiments. The experimental analysis shows that on the basis of fulcrum auxiliary support, the filling of paraffin melt material is capable of increasing the damping of the whole system, improving the overall stiffness of the machining system, and inhibiting the chatter effect of machining. This method is effective to greatly improve the accuracy and efficiency during machining of slender beam parts. On the premise of the method of processing support with the combination of fulcrum and paraffin, if the tool wear is effectively controlled, the high precision machining of large-scale slender beams can be realized effectively, and the machining deformation of slender beams can be reduced. Although high speed milling has excellent machining effect on the machining accuracy of titanium alloy materials, severe tool wear is observed during high-speed milling of titanium alloy materials. Therefore, high-speed milling of titanium alloy slender beam is suitable to be carried out in the finishing process, which can effectively control tool wear and improve the machining accuracy of parts. Finally, the process verification of typical weak stiffness slender beam skeleton parts is carried out. Through the theoretical and technical support of the experimental scheme, the machining of large-scale slender beam structure parts with weak stiffness is realized.

Tool Wear Characteristics in High Speed Milling of Ti-6Al-4V Alloy with Nitrogen Gas Medium

2006 ◽  
Vol 315-316 ◽  
pp. 588-592 ◽  
Author(s):  
Wei Zhao ◽  
Ning He ◽  
Liang Li ◽  
Z.L. Man
Keyword(s):  
Tool Wear ◽  
High Speed ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
High Speed Milling ◽  
Radial Depth ◽  
Oil Mist ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

High speed milling experiments using nitrogen-oil-mist as cutting medium were undertaken to investigate the characteristics of tool wear for Ti-6Al-4V Alloy, a kind of important and commonly used titanium alloy in the aerospace and automobile industries. Uncoated carbide tools have been applied in the experiments. The cutting speed was 300 m/min. The axial depth of cut and the radial depth of cut were kept constant at 5.0 mm and 1.0 mm, respectively. The feed per tooth was 0.1 mm/z. Optical and scanning electron microscopes have been utilized to determine the wear mechanisms of the cutting tools, and energy spectrum analysis has been carried out to measure the elements distribution at the worn areas. Meanwhile, comparisons were made to discuss the influence of different cutting media such as nitrogen-oil-mist and air-oil–mist upon the tool wear. The results of this investigation indicate that the tool life in nitrogen-oil-mist is significantly longer than that in air-oil-mist, and nitrogen-oil-mist is more suitable for high speed milling of Ti-6Al-4V alloy than air-oil-mist.

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