scholarly journals High-Efficiency Milling of Steam Turbine Blade

2016 ◽  
Vol 10 (6) ◽  
pp. 993-999 ◽  
Author(s):  
Xin Yuan ◽  
◽  
Takanori Yazawa ◽  
Hideo Ito ◽  
Tatsuki Otsubo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Steam Turbine ◽  
Turbine Blade ◽  
High Efficiency ◽  
Small Diameter ◽  
Surface Profile ◽  
End Mill ◽  
End Mills ◽  
Steam Turbine Blade

Conventional methods often use ball end mills with a small diameter to finish machining of a steam turbine blade to satisfy accuracy requirements by using a small pick feed value. Thus, the cutting length increases, resulting in increased wear and a lower milling efficiency. Therefore, a new method using a tilt-taper end mill is proposed. This paper presents the validity of the proposed method used for milling planes by comparing the ball and square end mills through tool wear experiments. Factors including removal degree, surface roughness, tool wear, and machined surfaces are investigated with respect to the plane model. The experimental results show that tilt end mill can retard the tool wear remarkably to obtain a steady surface profile, and the maximum surface roughness value, using the tilt-taper end mill, is less than 6μm until process completion.

Tool Wear and Surface Roughness in Milling of Die Steel Using Binderless CBN End Mill

2017 ◽  
Vol 11 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Kazuya Hamaguchi ◽  
◽  
Hiroyuki Kodama ◽  
Koichi Okuda ◽  
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
High Speed ◽  
Wear Volume ◽  
End Mill ◽  
Die Steel ◽  
Heat Treated ◽  
Finished Surface ◽  
End Mills ◽  
Heat Treated Steel

In this study, the authors describe the cutting characteristics of binderless CBN end mills in milling of die steel. A single flute radius end mill having a diameter of 0.5 mm and corner radius of 0.02 mm was in the experiment. Heat-treated steel, stainless steel, and high-speed tool steel were cut using a high-speed spindle, allowing for the analyses of tool wear and surface roughness. The results revealed that the wear volume increased with an increase in the hardness of the work material although the edge retreat amount after cutting 25 m was less than 5 μm. The average surface roughness of the finished surface was less than 15 nm in all the work materials. A mirror-finished surface was also obtained. This result contributes to the automation of the polishing process of metal molds and to the more efficient use of labor.

A Study of the Micro-End Milling of Titanium Alloy

2011 ◽  
Vol 325 ◽  
pp. 588-593 ◽  
Author(s):  
Koji Tsuda ◽  
Koichi Okuda ◽  
Hiroo Shizuka ◽  
Masayuki Nunobiki
Keyword(s):  
Surface Roughness ◽  
Experimental Investigation ◽  
Tool Wear ◽  
End Milling ◽  
Cutting Speed ◽  
Small Diameter ◽  
End Mill ◽  
High Speeds ◽  
Micro End Mill ◽  
Micro End Milling

This study deals with the cutting characteristics of titanium materials when milled by a small-diameter end mill, or a micro end mill. It is well known that titanium is difficult to cut by conventional means. However, its cutting characteristics have not yet been made sufficiently clear in cases where a micro end mill less than 1 mm in diameter is used. This study chiefly involves the experimental investigation of tool wear and surface roughness of micro-end milling of Ti-6Al-4V. The findings were that tool wear did not increase much when the cutting speed was increased from 50 m/min to 200 m/min. Furthermore, the cutting force required to cut decreased at high speeds and during wet cutting. In wet cutting, the surface had a roughness (Rz) of only 0.3 μm at 200 m/min in contrast to 0.6 μm at 50 m/min.

scholarly journals Study on high efficiency milling of steam turbine blade

2012 ◽  
Author(s):  
Xin Yuan ◽  
Takanori Yazawa ◽  
Nobutoshi Baba ◽  
Yukio Maeda ◽  
Yasuhiko Ougiya ◽  
...  
Keyword(s):  
Steam Turbine ◽  
Turbine Blade ◽  
High Efficiency ◽  
Steam Turbine Blade

scholarly journals Failure Analysis in Lacing Wire Of Last Stage Low Pressure Steam Turbine Blade

2021 ◽  
Vol 1096 (1) ◽  
pp. 012097
Author(s):  
A M Kongkong ◽  
H Setiawan ◽  
J Miftahul ◽  
A R Laksana ◽  
I Djunaedi ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Steam Turbine ◽  
Turbine Blade ◽  
Low Pressure ◽  
Pressure Steam ◽  
Steam Turbine Blade ◽  
Last Stage

Studies on Determination of Natural Frequencies of Industrial Turbine Blades

1995 ◽  
Author(s):  
Mahesh M. Bhat ◽  
V. Ramamurti ◽  
C. Sujatha
Keyword(s):  
Steam Turbine ◽  
Dynamic Behavior ◽  
Turbine Blade ◽  
Natural Frequencies ◽  
Complex Structure ◽  
Turbine Blades ◽  
Blade Root ◽  
Steam Turbine Blade ◽  
Manufacturing Tolerances

Abstract Steam turbine blade is a very complex structure. It has geometric complexities like variation of twist, taper, width and thickness along its length. Most of the time these variations are not uniform. Apart from these geometric complexities, the blades are coupled by means of lacing wire, lacing rod or shroud. Blades are attached to a flexible disc which contributes to the dynamic behavior of the blade. Root fixity also plays an important role in this behavior. There is a considerable variation in the frequencies of blades of newly assembled turbine and frequencies after some hours of running. Again because of manufacturing tolerances there can be some variation in the blade to blade frequencies. Determination of natural frequencies of the blade is therefore a very critical job. Problems associated with typical industrial turbine bladed discs of a 235 MW steam turbine are highlighted in this paper.

scholarly journals Cutting Performance of Different Coated Micro End Mills in Machining of Ti-6Al-4V

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 568 ◽  
Author(s):  
Zhiqiang Liang ◽  
Peng Gao ◽  
Xibin Wang ◽  
Shidi Li ◽  
Tianfeng Zhou ◽  
...  
Keyword(s):  
Tool Wear ◽  
Cutting Edge ◽  
Micro Milling ◽  
End Mill ◽  
Coating Materials ◽  
Edge Chipping ◽  
Workpiece Surface ◽  
Micro End Mill ◽  
End Mills ◽  
Flank Surface

Tool wear is a significant issue for the application of micro end mills. This can be significantly improved by coating materials on tool surfaces. This paper investigates the effects of different coating materials on tool wear in the micro milling of Ti-6Al-4V. A series of cutting experiments were conducted. The tool wear and workpiece surface morphology were investigated by analyzing the wear of the end flank surface and the total cutting edge. It was found that, without coating, serious tool wear and breakage occurred easily during milling. However, AlTiN-based and AlCrN-based coatings could highly reduce cutting edge chipping and flank wear. Specifically, The AlCrN-based coated mill presented less fracture resistance. For TiN coated micro end mill, only slight cutting edge chipping occurred. Compared with other types of tools, the AlTiN-based coated micro end mill could maximize tool life, bringing about an integrated cutting edges with the smallest surface roughness. In short, the AlTiN-based coating material is recommended for the micro end mill in the machining of Ti-6Al-4V.

Failure analysis of the 350MW steam turbine blade root

2009 ◽  
Vol 16 (4) ◽  
pp. 1270-1281 ◽  
Author(s):  
J. Kubiak Sz ◽  
J.A. Segura ◽  
G. Gonzalez R ◽  
J.C. García ◽  
F. Sierra E ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Steam Turbine ◽  
Turbine Blade ◽  
Blade Root ◽  
Steam Turbine Blade
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