Wall thickness monitoring method for wax pattern of hollow turbine blade

The wall thickness of hollow turbine blade has emerged as a significant cause of blade retirement. The precision of the final wall thickness of blade is mainly inherited from its corresponding wax pattern. The layout scheme of ceramic locators has a great influence on the wall thickness of wax pattern. A good layout of ceramic locators can significantly reduce the wall thickness shifting. To address this issue, a stable locator layout is needed to reduce the error transferring. The main purpose of this study is to find an optimal localization scheme for ceramic core. Firstly, the mathematical model of ceramic core localization was built based on the fixture design theory. Then, the optimal algorithm of locator layout design was studied. The D-optimality criterion has been chosen as optimal design criterion. Finally, two demonstration cases were presented. A localization scheme for real ceramic core was achieved and verified by using Monte-Carlo method. Moreover, the localization scheme was validated through experiments. Both simulation and experimental results indicated that the optimal localization can significantly reduce the input error.

[1]  Sarika Mishra,et al.  Reverse Solidification Path Methodology for Dewaxing Ceramic Shells in Investment Casting Process , 2010 .

[2]  Dinghua Zhang,et al.  Cavity optimization for investment casting die of turbine blade based on reverse engineering , 2010 .

[3]  D. Benny Karunakar,et al.  A Study on the Blended Wax Patterns in Investment Casting Process , 2011 .

[4]  Fei Li,et al.  Influence of complex structure on the shrinkage of part in investment casting process , 2015 .

[5]  S. Jack Hu,et al.  A Variational Method of Robust Fixture Configuration Design for 3-D Workpieces , 1997 .

[6]  M. Y. Wang,et al.  An optimum design for 3-D fixture synthesis in a point set domain , 2000, IEEE Trans. Robotics Autom..

[7]  Lucy Siu-Bik King,et al.  Theoretical approach for generating optimal fixturing locations for prismatic workparts in automated assembly , 1993 .

[8]  Pradeep Kumar Jha,et al.  Developments in investment casting process—A review , 2012 .

[9]  Syed H. Masood,et al.  An Investigation of Wax Patterns for Accuracy Improvement in Investment Cast Parts , 2001 .

[10]  Michael Yu Wang,et al.  Multi-objective optimal fixture layout design , 2002 .

[11]  Kun Bu,et al.  Geometric parameter-based optimization of the die profile for the investment casting of aerofoil-shaped turbine blades , 2011 .

[12]  Pradeep Kumar Jha,et al.  Multi-characteristic optimization of wax patterns in the investment casting process using grey–fuzzy logic , 2013 .

[13]  Yan Wang,et al.  Optimisation of machining fixture layout under multi-constraints , 2006 .

[14]  Andrew Y. C. Nee,et al.  Robust fixture layout with the multi-objective non-dominated ACO/GA approach , 2011 .

[15]  R Pradyumna,et al.  CERAMIC CORES FOR TURBINE BLADES : A TOOLING PERSPECTIVE , 2012 .

[16]  Adrian S. Sabau,et al.  Material properties for predicting wax pattern dimensions in investment casting , 2003 .

[17]  Supapan Chaiprapat,et al.  Modeling of positional variability of a fixtured workpiece due to locating errors , 2008 .

[18]  Kun Jiang,et al.  A multi-objective optimization and decision algorithm for locator layout continuous searching in checking fixture design , 2012, The International Journal of Advanced Manufacturing Technology.

[19]  H. Harry Asada,et al.  Kinematic analysis of workpart fixturing for flexible assembly with automatically reconfigurable fixtures , 1985, IEEE J. Robotics Autom..

[20]  Prasad K. Yarlagadda,et al.  Statistical Analysis of Accuracy of Wax Patterns Used in Investment Casting Process , 2003 .

[21]  E. C. De Meter,et al.  Tolerance Analysis of Machining Fixture Locators , 1999 .

[22]  Michael Yu Wang,et al.  Characterizations of localization accuracy of fixtures , 2002, IEEE Trans. Robotics Autom..

[23]  J. Zamani,et al.  An Experimental Comparison on Dimensional Accuracy of Wax Patterns of Gas Turbine Blades Produced by Rapid Tooling , 2014 .

[24]  A. Behravesh,et al.  An experimental investigation on dimensional stability of injected wax patterns of gas turbine blades , 2007 .