Optimization of Machining Parameters for Stress Concentration in Microdrilling of Titanium Alloy

This study employed a Taguchi-based experimental design to determine the experimental layout and optimal machining parameters for stress concentration in the microdrilling of titanium alloy. The finite element method (FEM) was used to analyze the characteristics of stress concentration in microdrilled holes. The signal-to-noise (S/N) ratio and analysis of variance (ANOVA) were employed to determine the optimal levels and the order of significance of the identified critical parameters affecting stress concentration. The critical control parameters in this study included rotational speed (rpm), feed rate (mm/min), cutting fluid, and holding length (mm). Results show that finite element simulation can effectively analyze the stress concentration of microholes. The stress concentration factor in a specimen is related to its microhole quality. The maximum stress concentration factor of the drilled hole was 4.46 times that of an ideal hole.

[1]  Phillip J. Ross,et al.  Taguchi Techniques For Quality Engineering: Loss Function, Orthogonal Experiments, Parameter And Tolerance Design , 1988 .

[2]  M. Niinomi,et al.  Microstructural Modification in a Beta Titanium Alloy for Implant Applications , 2006 .

[3]  D. Kubair,et al.  Stress concentration factor due to a circular hole in functionally graded panels under uniaxial tension , 2008 .

[4]  B. Meenan,et al.  Uniformity analysis of dielectric barrier discharge (DBD) processed polyethylene terephthalate (PET) surface , 2006 .

[5]  P. Arrazola,et al.  Machinability of titanium alloys (Ti6Al4V and Ti555.3) , 2009 .

[6]  E. Rahim,et al.  Performance of coated- and uncoated-carbide tools when drilling titanium alloy—Ti–6Al4V , 2007 .

[7]  Fritz Klocke,et al.  Examples of FEM application in manufacturing technology , 2002 .

[8]  Joseph C. Chen,et al.  Surface Roughness Optimization in a Drilling Operation Using the Taguchi Design Method , 2009 .

[9]  Rudolph Earl Peterson,et al.  Stress concentration design factors : charts and relations useful in making strength calculations for machine parts and structural elements , 1953 .

[10]  N. Jain,et al.  Finite element analysis for stress concentration and deflection in isotropic, orthotropic and laminated composite plates with central circular hole under transverse static loading , 2008 .

[11]  Raymond F. Wegman,et al.  Titanium and Titanium Alloys , 2013 .

[12]  Madhan Shridhar Phadke,et al.  Quality Engineering Using Robust Design , 1989 .

[13]  Suat Tanaydin Robust Design and Analysis for Quality Engineering , 1996 .

[14]  Margaret J. Robertson,et al.  Design and Analysis of Experiments , 2006, Handbook of statistics.

[15]  J. Keith Nisbett,et al.  Shigley's Mechanical Engineering Design , 1983 .

[16]  Albert J. Shih,et al.  High-throughput drilling of titanium alloys , 2007 .

[17]  Chongdu Cho,et al.  The concentration of stress and strain in finite thickness elastic plate containing a circular hole , 2008 .

[18]  Dave Kim,et al.  Drilling process optimization for graphite/bismaleimide–titanium alloy stacks , 2004 .

[19]  Flavio S. Fogliatto,et al.  Robust design and analysis for quality engineering , 1997 .

[20]  C. Leyens,et al.  Titanium and titanium alloys : fundamentals and applications , 2005 .

[21]  J. S. Khamba,et al.  Taguchi technique for modeling material removal rate in ultrasonic machining of titanium , 2007 .

[22]  Chi-Hsiang Lien,et al.  Optimization of the Polishing Parameters for the Glass Substrate of STN-LCD , 2008 .

[23]  B. B. Pradhan,et al.  Improvement in microhole machining accuracy by polarity changing technique for microelectrode discharge machining on Ti—6Al—4V , 2008 .

[24]  Dave Kim,et al.  Hole quality in drilling of graphite/bismalemide-titanium stacks , 2001 .

[25]  James R. Simpson,et al.  Robust Design and Analysis for Quality Engineering , 1998 .