World Applied Sciences Journal 21(Special Issue of Engineering and Technology): 23-30, 2013 ISSN 1818-4952 © IDOSI Publications, 2013 DOI: 10.5829/idosi.wasj.2013.21.1003 Corresponding Author: S. Thiru, Faculty of Mechanical Engineering, Universiti Teknikal Malaysia Melaka (UteM), Hang Tuah Jaya, 76100, Durian Tunggal, Melaka, Malaysia. Tel: +606-2346739, E-mail: thiru@utem.edu.my. 23 Prediction and Measurement of Weld Dilution in Robotic CO Arc Welding 2 S.Thiru, Chew Lai Huat, Kamaruzaman Jusoff, S. Hemavathi, 1 1 2 3 Phang Boo Onn, Febrian bin Idral and Md Radzai Said 1 1 1 Faculty of Mechanical Engineering, Universiti Teknikal Malaysia Melaka (UteM), 1 Hang Tuah Jaya, 76100, Durian Tunggal, Melaka, Malaysia Department of Forest Production, Faculty of Forestry, 2 Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia School of Civil Engineering, Linton University College, 71700, Mantin, Negeri Sembilan, Malaysia 3 Abstract: Weld dilution is an important feature of weld bead geometry that determines the mechanical and chemical properties of a welded joint. For robotic CO arc welding, several welding process parameters are 2 reported to be controlling the dilution.This paper investigates the relationship between four of these process parameters and dilution by depositing ‘bead on plate’ robotic CO arc welds over mild steel plates. 2 Two level four factor full factorial design method was used for conducting the experimental runs and linear regression models were developed accordingly. The adequacy of the models were tested by applying students ‘t’ test and the predicted values from the models were plotted against the observed values through scatter diagram. Results showed that the proposed two level full factorial empirical models could predict the weld dilution with reasonable accuracy and ensure uniform weld quality. It can be concluded that robotic CO arc welding is a very simple and effective tool for quantifying the main and interactive effects of 2 welding parameters on dilution. Future works should focus in analyzing the influence of variable pure gasses as well as the gas mixture on dilution percentage in robotic arc welding. Key words: Robotic CO Arc Welding %Process Control Parameters %Weld Dilution %Mathematical Modeling 2 INTRODUCTION industrial applications. These applications include from Weld surfacing is a metal deposition process in the petrochemical,cement,fertilizer and nuclear power plants form of a single or multiple layers over a basemetal, [2]. Although most of the conventional welding generally named as substrate. Based on the function, processes viz., shielded metal arc welding (SMAW), there are several classifications in surfacing process, submerged arc welding (SAW), gas tungsten arc welding namely a) hardfacing - the deposition to produce high (GTAW), plasma arc welding (PAW), flux cored arc wear resistance surfaces over a ductile base metal; b) welding (FCAW), electroslag welding (ESW), oxy- cladding-to produce high corrosion resistant surfaces acetylene welding (OAW) and explosive welding are through deposition; c) buttering - a process of making extensively employed by the industry [3], however gas chemically or metallurgically compatible surfaces; and d) metal arc welding (GMAW) is one of the most the metal deposition to reconstruct and reuse the worn recognised and widely used process for all types of weld out parts [1]. surfacing mainly due to its high productivity and ease of Surfacing by fusion welding process has been automization. increasingly becoming popular as it substantially saves In general, the automized/robotic arc welding some of the most imperative costs that involve men, process has several means to sense and regulate the machines, materials and manufacturing and has been various,interdependant process control variables so as to evolved rapidly in recent years for a wide range of ensure the process-product quality, productivity and relatively smaller food processing plants to much bigger