Surface Roughness Report and 3D Surface Analysis of Hybrid Metal Matrix Composites (MMC) During Abrasive Water Jet (AWJ) Cutting Ashish Kumar Srivastava, Shashi Prakash Dwivedi, Nagendra Kumar Maurya * , Rohit Sahu Department of Mechanical Engineering, G.L. Bajaj Institute of Technology and Management, Greater Noida, GB Nagar 201306, India Corresponding Author Email: nagendra.maurya@glbitm.org https://doi.org/10.18280/rcma.303-407 ABSTRACT Received: 23 November 2019 Accepted: 16 January 2020 The conventional machining of engineering hard materials like composites is a challenging task due to rapid tool wear and high machining cost. In this context, the non-conventional machining such as abrasive waterjet cutting is mostly utilized for the cutting of such hard materials due to its tremendous machining outcomes. Here an attempt is made to cut the previously developed sample of hybrid metal matrix composite A359/B4C/Al2O3 by abrasive waterjet machining process. Three different samples with change proportions of reinforcement from 2% to 4% were used in this study to create the flat machined surfaces. The surface roughness profile and 3D surface detailing are generated through the microprof FRT machine and inbuilt measuring sensor. Result revels that rough cutting with the average surface roughness value ranges from 7 to 9 μm for the selected samples. The machined surface is full of cutting traces with some of macro pores of size 1.2 mm to 1.8 mm observed by 3D profile views. Keywords: hybrid MMC, A359 aluminum alloy, surface roughness, 3D profile view, abbreviations 1. INTRODUCTION The advancement in the technology increases the demand of new class of engineering materials. In this view, the development of metal matrix composites (MMCs) was introduced from last few decades [1]. The excellent properties of MMCs such as improved mechanical, thermal and physical properties as well as its light weight and anti- corrosion eminence makes it suitable for most of the engineering applications [2, 3]. However, the machining results of MMCs are not satisfactory reported by most of the authors [4, 5]. The problem arises with conventional cutting or turning are the rapid tool wear due to occurrence of tough coarse particles in the MMCs and larger machining time, which increases the overall machining cost [6, 7]. Nowadays non-conventional machining is mostly utilized for the machining of such hard materials like composites [8]. The reason behind this selection is the non-physical contact between the tool and workpiece and negligible cutting forces [9]. In the field of non-conventional process, abrasive water jet (AWJ) is most suitable application because it does not require the conductance of the material to be cut [10]. The mechanism of cutting by AWJ process was based on the plastic deformation. A jet of high-pressure water including high velocity abrasive particles strikes the workpiece surface, which removes the required excess materials [11]. The process is controlled with the support of its variable like abrasive mass flow rate, traverse speed, nozzle speed, type of abrasive, work piece rotation etc. [12]. The major advantage of the AWJ process is its cold cutting (there is no heat generated during the cutting operation [13]. The process is also capable for larger material removal rate and improved fatigue strength of the machined surface due to the pinning action on the workpiece surface [14]. Machining with AWJ can be applied for turning, drilling and milling as per requirement of the industry. However, the surface roughness of the AWJ machined surface is high compared to the other machining processes reported by most of the authors [15-17]. This is due the fact that the ploughing nature of cutting was observed with plastic deformation. Another reason for high surface roughness is the creation of long thin grooves on the machined surface and random cutting traces. Several studies have been carried out related to machining of hard material through conventional process. From archival literature it can be concluded that machining of hybrid metal matrix composite is difficult through conventional machining operation. Surface roughness of the machined components through conventional machining is high. To overcome the machining difficulty if hard material an attempt is made to cut the previously developed sample of hybrid metal matrix composite A359/B4C/Al2O3 by abrasive waterjet machining process. The experiments were performed on waterjet machine of model CNC WJ2020B-1Z-D. Three different samples with change proportions of reinforcement from 2% to 4% were used in this study to create the flat machined surfaces. The surface roughness profile and 3D surface detailing are generated through the microprof FRT machine and inbuilt measuring sensor. 2. EXPERIMENTAL PROCEDURE In this investigation A359/B4C/Al2O3 hybrid metal matrix composite material is developed through electromagnetic stir casting process. A359 is used as matrix material whereas B4C and Al2O3 were used as reinforcement martial. Due to the Revue des Composites et des Matériaux Avancés-Journal of Composite and Advanced Materials Vol. 30, No. 3-4, August, 2020, pp. 169-174 Journal homepage: http://iieta.org/journals/rcma 169