Session: 03-03 Metals: Path Development

Paper Number: 93937

93937 - Evaluation of Contour Deposition for Various Corner Angles in Lbpf 

Laser powder bed fusion (LPBF) is one of the most important additive manufacturing processes for fabricating complex geometries of metallic components which range from macro to micro size. Very complex and large-size products with various parts can be fabricated by this process as a single product directly without assembling the parts. Even though the complex geometries could be fabricated by LPBF, the fabrication of the component with sharp corners is a great challenge in this process. The difference in size producing sharp features with required features is more as the size of the feature approaches toward the laser spot diameter, and even distorts the geometrical characteristics of micro-size features. Among the process parameters the scanning strategy plays an important role in the dimensional and geometrical accuracy of a part. In LPBF the part is fabricated using laser source by following the scanning strategy which divides into infill (the core of part) and contour (outer boundary of part) exposures. Generally, contour shows the significant influence on dimensional and geometry accuracy of a part as compared to infill. The process parameters of the contour/outer boundary exposure like laser spot diameter, laser power, scanning speed, powder size distribution, etc. are greatly influence the width of the contour formation. 

In this study the only contour is considered, and analyzed the geometrical variation of the contour on various corner angles (α=30°, 60°, 90°, and 120°).  The geometric analysis of contour was carried out using a scanning electron microscope followed by the image analysis software. The contour width at the corner is wider than the contour width at edges more than 10 %.   The numerical model is used to predict the suitable process parameters to produce the contour width with less variation between corners and edges. The temperature field of Ti-6Al-4V powder was performed for various parametric conditions using COMSOL Multiphysics®. The effect of laser power and scanning speed on melt pool characteristics was investigated experimentally and numerical model results were reliable with the experiment results.  A new method is proposed in this study to produce a constant width along the entire contour.

Presenting Author: Kanmani Subbu Subbian Indian Institute of Technology Palakkad.

Presenting Author Biography: Dr. S. Kanmani Subbu, is working as Assistant Professor in the discipline of Mechanical<br/>Engineering IIT Palakkad. After completing his Doctorate from the Indian Institute of Technology<br/>Kanpur, and he worked as Assistant Professor in the National Institute of Technology Warangal (NIT<br/>Warangal) for 4 &#189; years. His area of expertise includes micro manufacturing, laser surface<br/>processing, composite fabrication and machining, Additive Manufacturing. He has published<br/>more than 80 international journal publications and international conferences. He has executed<br/>projects from SERB, DST. He is a member of IEI, Laser Association, and ISME. He has<br/>conducted two GIAN workshops, two STTPs, and one faculty development program. He is the<br/>guest editor for a special issue of the Journal of Micromanufacturing, SAGE Publisher.

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