Manufacturing Technology Today

G. Kibria ¹, B. Doloi ², B. Bhattacharyya ²

Affiliations
1 Mechanical Engineering Department, Aliah University, Kolkata, IN
2 Production Engineering Department, Jadavpur University, Kolkata, IN

Abstract

The present paper addresses the laser micro-turning process of aluminium oxide (Al₂O₃) ceramics of size 10 mm in diameter and 40 mm in length. The experiments have been conducted using response surface methodology design of experiments. The targeted depth was set at 100 μm. Laser average power, pulse frequency, workpiece rotating speed, air pressure and Y feed rate were considered as process variables. After each experiment, surface roughness (Ra) and micro-turning depth deviation have been measured. Multi-objective optimization has been done to obtain optimal values of responses i.e. surface roughness and depth deviation. To achieve further high quality machined surface, machining was done at various defocusing conditions of laser beam and also by varying the number of laser scan passes. Other parameters were kept constant at optimal parametric combination obtained in multi-objective optimization. From the experimental results, it was revealed that surface roughness decreases with increase in defocusing positions. With increase in number of passes up to a certain limit, surface roughness decreases. However, depth deviation increases with number of laser scan passes at all levels of defocus planes.

Keywords

Pulsed Nd:YAG Laser, Laser Micro-Turning, Surface Roughness, Advanced Ceramics, Aluminium Oxide (Al₂O₃), Defocusing Positions.

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G. Kibria ¹, B. Doloi ¹, B. Bhattacharyya ¹

Affiliations
1 Prod. Engg. Dept., Jadavpur University, Kolkata, IN

Abstract

Laser beam machining (LBM) is a non-contact type of material removal process and this advanced thermal machining process is extensively used worldwide in material processing field in modern industries. The high density focused laser beam melts and vaporizes the unnecessary portion of parent material very efficiently. During the last decades, a number of researchers have explored experimentally and theoretically this Nd:YAG laser beam machining technique with different materials like metals, alloys, ceramics and composites through a number of ways to improve the machining performances. The paper reviews the research works performed in the area of Nd:YAG laser micromachining operations such as micro-drilling, microgrooving, micro-cutting, micro-milling, micro-turning and marking etc. on aduanced engineering ceramics for searching out the various micro-machining process parameters and their effects on laser machining performance characteristics.

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