American Journal of Mechanical Engineering, 2017, Vol. 5, No. 3, 94-109 Available online at http://pubs.sciepub.com/ajme/5/3/5 ©Science and Education Publishing DOI:10.12691/ajme-5-3-5 Grey Relational Analysis of Chemical Assisted USM of Polycarbonate Bullet Proof (UL-752) & Acrylic Heat Resistant (BS-476) Glass Kanwal Jeet Singh 1,* , Inderpreet Singh Ahuja 2 , Jatinder Kapoor 3 1 Department of Mechanical Engineering, Giani Zail Singh Campus College of Engineering & Technology, Bathinda, Punjab, India 2 Department of Mechanical Engineering, University College of Engineering, Punjabi University, Patiala, Punjab, India 3 Department of Production Engineering, Guru Nanak Dev Engineering College, Ludhiana, Punjab, India *Corresponding author: khalsa.kanwal@yahoo.com Abstract This paper is developed an innovative process of chemical assisted ultrasonic machining of polycarbonate bullet proof UL-752 and acrylic heat resistant BG-476 glass and conduct an investigation for optimize the machining parameters associated with multiple performance characteristics using Grey relational analysis. Machining of polycarbonate bullet proof UL-752 and acrylic heat resistant BS-476 glass are difficult process via conventional machining, however, it can be easily machined by Ultrasonic machining. Carefully selected parameters gives the optimum results. In this experimental work input parameters abrasive slurry concentration, type of abrasive, power rate, grit size of abrasive particles, hydro-fluoride acid concentration and tool material are selected. The effect of input parameters viz material removal rate, tool wear rate and surface roughness are investigate. Grey relational analysis and analysis of variance are performed to optimize the input parameters and better output results. In PBPG UL-752, increment in material removal rate by 75.58%, tool wear rate by 45.34% and surface roughness by 34.18%. In other hand, in AHRG BS-476, increment in material removal rate by 61.24%, tool wear rate by 31.46% and surface roughness by 23.85%. The surface topography is investigate through SEM images. It also observed that HF acid have the significant role in surface roughness. It also reduce the micro cracks on machined zone. Harder tool and harder abrasive slutty gives the higher material removal rate, but it also enhance the tool wear rate. Keywords: USM, polycarbonate, acrylic, bullet proof, heat resistant, glass, HF acid, grey relational analysis Cite This Article: Kanwal Jeet Singh, Inderpreet Singh Ahuja, and Jatinder Kapoor, “Grey Relational Analysis of Chemical Assisted USM of Polycarbonate Bullet Proof (UL-752) & Acrylic Heat Resistant (BS-476) Glass.” American Journal of Mechanical Engineering, vol. 5, no. 3 (2017): 94-109. doi: 10.12691/ajme-5-3-5. 1. Introduction Ultrasonic machining (USM) is generally preferred for amorphous, hard and brittle materials. Glass, ceramics, titanium, titanium alloys and many more materials are easily machined with USM [1,2,3]. If the hardness of material is more than 40 HRC then USM is effectively performed. Micro holes as small as 76 µm diameter can be easily drilled by USM. The ratio of depth to diameter is limited to 3:1. During USM neither chemical nor thermal changes occur [5]. Moreover, no any metallurgical variations arise on work surface [4]. The history of USM started since 1927 with a research paper reported by A.L. Loomis and R.W. Wood [8]. American engineer Lewis Balamuth in 1945 was granted first patent [9]. USM process have been classified as ultrasonic drilling, ultrasonic cutting, ultrasonic abrasive and ultrasonic dimensional machining [10,30]. In early 1950’s ultrasonic grinding was modified into ultrasonic impact machining. It was significant machining process and capable to machine toughest materials [11]. In USM process, power supply have an important role. It convert low frequency electrical signals into high frequency electrical signals [11,12]. After that these signals are transmitted to transducer. Two type of transducer are generally used, magnetostatic and piezoelectric transducer [14,31]. The transducer converts high frequency electrical signals into mechanical vibrations. Through horn, the effect of vibrations are amplified and concentrate on tool assembly. USM tool vibrates along its longitudinal axis with ultrasonic frequency between 20 kHz to 40 kHz [3,14,15]. The amplitude of vibrations are measured in few hundredth of millimeters along longitudinal axis of tool. Horn and tool must be designed with mass and shape considerations, so that the resonance effect can be achieved with in the frequency range [15,16]. Power rating of USM varies in between 50 W to 4000 W. Along longitudinal axis controlled static load is applied on the USM tool. Mixture of abrasive and carrier medium is known as slurry. The concentration of slurry varies from 30% to 50% by volume [17,29]. It is pumped in between the gap of tool and work surface. The optimum pumping speed of slurry is 30 litter/ min [15,18]. Water is commonly used as a