Functional Testing of Direct Metal Laser Sintered (DMLS) Components for Automotive Application C. D. Naiju 1,a , M. Adithan 1,b , P. Radhakrishnan 2,c , Y. Upendra Sravan 1,d 1 SMBS, VIT University, Vellore, 632014, India. 2 Institute of Advanced Studies, PSG Tech, Coimbatore, India. a naijucd@gmail.com, b director.asc.vit.ac.in, c rkp_n@yahoo.com, d upendra.sravan@gmail.com Key words: DMLS, Laser processing, Wear, Functional testing Abstract. This work presents the results of a study to determine the wear behavior of components manufactured by direct metal laser sintering (DMLS). Wear is an important issue in using layer manufactured parts for functional application. Two different bushes were selected for the functional testing for wear behavior studies. Specimens (bushes) were manufactured by DMLS technology and was tested for wear behavior and compared with bushes manufactured by conventional manufacturing methods. Components were manufactured by using the process parameters like sintering speed, hatch spacing, post contouring speed, hatch type and infiltration with an optimized value. Testing was carried out for bushes, used for an automobile engine starter motor. A comparative study for the wear behavior was carried out and results are discussed. Introduction Layered manufacturing, over the years have become more and more popular in the field of rapid manufacturing. These technologies were used mainly for prototyping application. Now a days it is gaining popularity in using it for the functional application. Direct Metal Laser Sintering is one of the techniques of layered manufacturing, used to create solid parts with metallic powder directly from CAD data. The physical and mechanical properties of these rapid prototyped parts need to be studied in detail for using it for functional application. The need and importance for research related to rapid prototyping is of great relevance [1]. Wear behavior is one of the issues that have to be considered while using layer-manufactured parts for functional applications such as long-term tooling application for injection molding, die casting, automotive and aerospace parts. The performances of machines or parts are mainly due to the wear of components subjected to rubbing or sliding action. A detailed study is reported for different rapid prototyping process, material used and application in engineering field [2]. Properties of layer-manufactured parts like, tensile strength have been studied exhaustively and experiments carried out using DMLS parts showed better tensile strength at lower sintering speeds [3]. Research undertaken by various researchers reveals an interesting observation that low melting point infiltration of alloy could improve the hardness and a coating using nickel was suggested to improve the hardness and wear resistance [4]. A parameter optimization study was carried out in DMLS to improve strength of layer manufactured components. Sintering speed and infiltration were found to have significant influence on tensile strength and compressive strength of the components [5]. The effect of variation of process parameters like layer thickness and hatching distance on density, hardness and porosity of sintered parts is reported [6]. Duck et.al [7] have forecast the reliability of coated tools in industrial application by measurements of friction coefficient, wear rate of laser sintered and coated parts. The reason for lower values of bending strength, hardness and wear resistance is the porosity of laser-sintered parts by DMLS. A higher density is obtained with higher laser power or lower scan rate [8]. Application of rapid prototyping in manufacture of moulds and other tooling application are studied and presented [9]. A reliability study on fatigue strength is reported for test results [10]. Previous reports reveals that though a number of investigators have studied the physical and mechanical of parts produced by sintering process, the comparative study on behavior of conventionally manufactured parts and DMLS parts under Advanced Materials Research Vols. 383-390 (2012) pp 6242-6246 © (2012) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/AMR.383-390.6242