Development and Testing of High Temperature Silicon Nitride Microturbine Rotors

2008 ◽  
Author(s):  
Vimal Pujari ◽  
Ara Vartabedian ◽  
Gregg Wayman
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Gas Turbine ◽  
Surface Finish ◽  
Systems Approach ◽  
Cutting Tools ◽  
High Yield ◽  
Machining Parameters ◽  
Dimensional Control ◽  
Machined Surface

Development and testing of gas turbine quality high temperature silicon nitride (NT154) components will be described. An advanced CNC green (using pressed powder blanks prior to densification) machining based complex shape forming methodology has been developed and successfully deployed to fabricate gas turbine quality rotor, vane ring and shroud components to net shape with high yield and required dimensional tolerances. Utilizing a systems approach involving green blank properties, type of cutting tools and machining parameters, the process has been optimized to achieve required as machined surface finish, dimensional control and part integrity. Integral bladed micro turbine rotors (IBR) and vane rings have been fabricated with dimensional control within 100 microns, surface finish within 1–2 microns. IBRs so formed have been successfully spin tested at room temperature at 40% above designed speed approaching maximum stress in the vicinity of 400 MPa.

Development and Fabrication of Silicon Nitride Components for Ceramic Gas Turbine

1997 ◽  
Author(s):  
Keisuke Makino ◽  
Ken-Ichi Mizuno ◽  
Toru Shimamori
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Blades ◽  
High Strength ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Spark Plug ◽  
Power Turbine

NGK Spark Plug Co., Ltd. has been developing various silicon nitride materials, and the technology for fabricating components for ceramic gas turbines (CGT) using theses materials. We are supplying silicon nitride material components for the project to develop 300 kW class CGT for co-generation in Japan. EC-152 was developed for components that require high strength at high temperature, such as turbine blades and turbine nozzles. In order to adapt the increasing of the turbine inlet temperature (TIT) up to 1,350 °C in accordance with the project goals, we developed two silicon nitride materials with further unproved properties: ST-1 and ST-2. ST-1 has a higher strength than EC-152 and is suitable for first stage turbine blades and power turbine blades. ST-2 has higher oxidation resistance than EC-152 and is suitable for power turbine nozzles. In this paper, we report on the properties of these materials, and present the results of evaluations of these materials when they are actually used for CGT components such as first stage turbine blades and power turbine nozzles.

Machining Finish of Titanium Alloy Prepared by Additive Manufacturing

2017 ◽  
Vol 872 ◽  
pp. 43-48 ◽  
Author(s):  
Xin Huang ◽  
Qian Bai ◽  
Yong Tao Li ◽  
Bi Zhang
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Additive Manufacturing ◽  
Surface Finish ◽  
Functional Performance ◽  
Critical Role ◽  
Lower Surface ◽  
Machining Parameters ◽  
Machined Surface ◽  
Slot Milling

Surface finish plays a critical role in functional performance of machined components. This study investigates machining finish of Ti-6Al-4V alloy prepared by Additive Manufacturing (AM) with a series of slot-milling experiments. The study compares the machined AMed part with that made of the conventional wrought Ti-6Al-4V. The microstructure of AMed parts is acicular α and Widmanstatten α lath structures compared to lamellar α structure of that in the wrought parts. Due to the unique microstructure from AM process, the AMed parts present higher strength and lower ductility. Therefore, a lower surface roughness is obtained in the milling of AMed parts compared to its counterpart of wrought parts. In addition, the machined surface of AMed parts possesses a topography of discontinued ridges. It is believed that the topography is due to low ductility of AMed part. The results show that the machined AMed part presents better surface finish. The study provides a guidance to optimization of machining parameters for AMed Ti-6Al-4V alloys.

scholarly journals Polishing of Silicon Nitride Ceramic Balls by Clustered Magnetorheological Finish

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 304
Author(s):  
Xiao-lan Xiao ◽  
Guang-xian Li ◽  
Hai-juan Mei ◽  
Qiu-sheng Yan ◽  
Hua-tay Lin ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Analytical Model ◽  
Surface Finish ◽  
Experimental Results ◽  
Machined Surface ◽  
Silicon Nitride Ceramic ◽  
Ceramic Ball ◽  
Contact Points ◽  
Micro Morphology ◽  
Improve Surface Finish

In this study, a novel finishing method, entitled clustered magnetorheological finish (CMRF), was proposed to improve surface finish of the silicon nitride ( Si 3 N 4 ) balls with ultra fine precision. The effects of different polishing parameters including rotation speeds, eccentricities and the machining gaps on surface finish of Si 3 N 4 balls were investigated by analyzing the roughness, sphericity and the micro morphology of the machined surface. The experimental results showed that the polishing parameters significantly influenced the surface finish. The best surface finish was obtained by using the polishing parameters: the machining gap of 0.8 mm, the eccentricity of 10 mm and the rotation ratio of 3/4. To further investigate the influence of the polishing parameters on the surface finish, an analytical model was also developed to analyze the kinematics of the ceramic ball during CMRF process. The resulting surface finish, as a function of different polishing parameters employed, was evaluated by analyzing the visualized finishing trace and the distribution of the contact points. The simulative results showed that the distribution and trace of the contact points changed with different polishing parameters, which was in accordance with the results of experiments.

FRACTAL-BASED ANALYSIS OF THE EFFECT OF MACHINING PARAMETERS ON SURFACE FINISH OF WORKPIECE IN TURNING OPERATION

Fractals ◽  
2019 ◽  
Vol 27 (04) ◽  
pp. 1950043 ◽  
Author(s):  
GEEVIN JITHMAL PATHIRANAGAMA ◽  
HAMIDREZA NAMAZI
Keyword(s):  
Surface Quality ◽  
Surface Finish ◽  
Feed Rate ◽  
Fractal Theory ◽  
Complex Structure ◽  
Spindle Speed ◽  
Machining Parameters ◽  
Cutting Depth ◽  
Machined Surface ◽  
Turning Operation

Analysis of workpiece surface quality is one of the major issues in manufacturing engineering. Turning operation is a famous machining operation that is widely used in machining of materials. In this research, we investigate the surface finish of machined workpiece from turning operation. For this purpose, we employ fractal theory to study the complex structure of machined workpiece’s surface in different conditions. The applied parameters include the variations of cutting depth, feed rate and spindle speed in wet and dry machining conditions. Based on the obtained results, we found the correlation between the increment of fractal dimension of machined surface and the increment of cutting depth, feed rate and spindle speed in wet machining condition. The obtained results will be discussed in relation with the complexity of machined surface. The employed method of analysis in this research can be widely applied to the analysis of the effect of different machining parameters and conditions on the surface quality of machined workpiece in case of different machining operations.

The Effect of the Cutting Parameters on the Machined Surface Roughness

2017 ◽  
Vol 260 ◽  
pp. 219-226 ◽  
Author(s):  
Viktors Gutakovskis ◽  
Eriks Gerins ◽  
Janis Rudzitis ◽  
Artis Kromanis
Keyword(s):  
Surface Roughness ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Cutting Parameters ◽  
Cutting Process ◽  
Tool Geometry ◽  
Machining Parameters ◽  
Machined Surface ◽  
Machined Surface Roughness

From the invention of turning machine or lathe, some engineers are trying to increase the turning productivity. The increase of productivity is following after the breakout in instrumental area, such as the hard alloy instrument and resistance to wear cutting surfaces. The potential of cutting speed has a certain limit. New steel marks and cutting surfaces types allow significantly increase cutting and turning speeds. For the most operation types the productivity increase begins from the feeding increase. But the increase of feeding goes together with machined surface result decreasement. Metal cutting with high feeding is one of the most actual problems in the increasing of manufacturing volume but there are some problems one of them is the cutting forces increasement and larger metal removal rate, which decrease the cutting tool life significantly. Increasing of manufacturing volume, going together with the cutting instrument technology and material evolution, such as the invention of the carbide cutting materials and wear resistant coatings such as TiC and Ti(C,N). Each of these coating have its own properties and functions in the metal cutting process. Together with this evolution the cutting tool geometry and machining parameters dependencies are researched. Traditionally for the decreasing the machining time of one part, the cutting parameters were increased, decreasing by this way the machining operation quantity. In our days the wear resistance of the cutting tools increasing and it is mostly used one or two machining operations (medium and fine finishing). The purpose of the topic is to represent the experimental results of the stainless steel turning process, using increased cutting speeds and feeding values, to develop advanced processing technology, using new modern coated cutting tools by CVD and PVD methods. After investigation of the machined surface roughness results, develop the mathematical model of the cutting process using higher values of the cutting parameters.

Development and Evaluation of Ceramic Components for Gas Turbine

2002 ◽  
Author(s):  
Takero Fukudome ◽  
Sazo Tsuruzono ◽  
Wataru Karasawa ◽  
Yoshihiro Ichikawa
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Technology Development ◽  
Inlet Temperature ◽  
Combustion Gas ◽  
Development Organization ◽  
Nitride Material ◽  
Ceramic Components

An 8000 kW class Hybrid Gas Turbine (HGT) project, administered by the New Energy and Industrial Technology Development Organization (NEDO), has been ongoing since July of 1999 in Japan. Targets of this project are improvement in thermal efficiency and output power by using ceramic components, and early commercialization of the gas turbine system. The ceramic components are used for stationary parts subjected to high temperature, such as combustor liners, transition ducts, and first stage turbine nozzles. Development of the gas turbine is conducted by Kawasaki Heavy Industries, Ltd. (KHI), to achieve the Turbine Inlet Temperature (TIT) of 1250°C, thermal efficiency of 34%, NOx emission less than standard regulation values, and 4,000 h engine durability. Kyocera is in charge of the development and evaluation of the ceramic components. Recently, recession of the Si based ceramic materials under the combustion gas is the focus of attention to improve the reliability of ceramic components for gas turbine. For the HGT project, the silicon nitride material (SN282 : silicon nitride material produced by Kyocera Corporation) is used for the components subjected to high temperature. The SN282 was evaluated under the combustion gas, and clear recession was observed. Our technology of the Environmental Barrier Coating (EBC) is under development to obtain reliable heat resistive SN282 components, against the recession by combustion gas. Reliability of the SN282 with EBC has been evaluated by exposure and hydrothermal corrosion test. Ceramic components made of SN282 with EBC will be also evaluated by a proof engine test of 4,000 h, which starts in the spring of 2002.

scholarly journals Development of Advanced Surface Engineering Technologies for the Benefit of Multipoint Cutting Tools

2009 ◽  
Vol 83-86 ◽  
pp. 1043-1050
Author(s):  
Mohammed Sarwar ◽  
Julfikar Haider
Keyword(s):  
High Speed ◽  
Surface Engineering ◽  
Cutting Tool ◽  
Systems Approach ◽  
Single Point ◽  
Cutting Tools ◽  
Substrate Material ◽  
End Users ◽  
Machined Surface ◽  
Edge Conditions

The benefits of applying advanced coatings on both single point and multipoint cutting tools such as improvement of productivity, tool life, machined surface quality etc. have been realised by the surface engineering researchers [1], commercial coaters [2-4] and end users [5]. The demand for advanced coatings in cutting tool industries is continually growing to meet the challenges of high speed machining, dry machining, near net-shape machining, machining of hard-to-cut materials etc.. Advanced coatings with excellent properties on flat coupon in a laboratory deposited by modern deposition technologies should not be taken for granted in improving the performance of complex shaped cutting tools [6] in aggressive cutting environments. This is because the end performance of coated cutting tools is not only dependant on the coating itself but also on the tool substrate material, geometry, surface finish and cutting edge conditions prior to coating deposition. The paper presents case studies with examples of successes and failures of advanced coatings on different multipoint cutting tools (e.g., milling cutters, bandsaws, circular saws, holesaws etc.). The future strategy for developing successful coating technology for cutting tools should be directed towards adopting a systems approach to bridge the communication gap amongst the cutting tool manufactures, tool coaters and end users.

scholarly journals Experience in the Manufacture of Gas Turbine Vanes of Hot Pressed Silicon Nitride and Silicon Carbide

1975 ◽  
Author(s):  
R. K. Bart ◽  
E. W. Hauck ◽  
M. L. Torti
Keyword(s):  
Silicon Carbide ◽  
Silicon Nitride ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Diamond Wheel ◽  
Machining Parameters ◽  
Development Programs ◽  
Materials Development ◽  
Turbine Vanes ◽  
Engineering Materials

The introduction of ceramic vanes into gas turbines has required simultaneous materials and manufacturing development programs. A review of the materials development programs is presented to show that hot pressed silicon nitride and silicon carbide are consistent engineering materials. A discussion of general machining parameters including diamond wheel specifications is presented to provide guidance in the preparation of turbine components from hot pressed silicon nitride and silicon carbide.

Advanced Machining Technology for Gas Turbine and Heat Engine Components

2006 ◽  
Vol 45 ◽  
pp. 1765-1770
Author(s):  
Vimal K. Pujari ◽  
Ara Vartabedian ◽  
William T. Collins
Keyword(s):  
Systems Approach ◽  
Heat Engine ◽  
Cutting Tools ◽  
Cost Effective ◽  
Machining Parameters ◽  
Forming Technology ◽  
Fabrication Procedure ◽  
Advanced Machining ◽  
Ceramic Manufacturing ◽  
Engine Components

Cost effective ceramic manufacturing with green and dense machining perspectives has been described. An advanced CNC green machining based complex shape forming technology developed at Saint-Gobain is described which has been shown to be robust and capable of rapid prototyping. Utilizing a systems approach involving green blank properties, type of cutting tools and machining parameters the procedure has been optimized. Integral Bladed Rotors (IBR) for microturbine applications have been fabricated with dimensional controls within 0.15% and successfully spin tested at 143330 rpm without failure. Following this approach, a cost effective machining and prototype fabrication procedure is under development for IBR and Vane rings for various civilian and military applications.

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