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OPTIMIZATION OF PROCESS PARAMETERS FOR POCKET MILLING
OF AL7075 USING RESPONSE SURFACE METHODOLOGY
M. RAJYALAKSHMI
1*
& Dr. P. SURESH BABU
2
1
Department of Mechanical Engineering, PVP Siddhartha Institute of Technology, Vijayawada, Andhra Pradesh, India
2
Department of Mechanical Engineering, AAR Mahaveer Engineering College, Hyderabad, Telangana, India
ABSTRACT
Nowadays, the high quality of surface finish is in demandto meet the market requirements. Manufacturing
industry has many complex processes that vary in nature. The current paper describes the development of a model for
pocket milling on Al7075 using Response Surface Methodology (RSM). This model gives mathematical relationships in
terms of Cutting speed, Feed and Step Over for Follow periphery and Zigzag tool path strategies. The Surface Roughness
(SR) is predicted with these relationships and compared with the measured surface roughness of the machined
components. The error observed is less than 5% between predicted and measured values.
KEYWORDS: Pocket Milling, Aluminium, RSM, Tool Path Strategy & Optimization
Received: May 13, 2019; Accepted: Jun05, 2019; Published: Jul 06, 2019; Paper Id.: IJMPERDAUG201965
INTRODUCTION
Surface integrity is one of the most influencing factors to accept the quality of a product in many
manufacturing components. In modern manufacturing world with computer numerical control machines, achieving
surface quality is not a much difficult task. But with trial and error methods, much of the valuable production time
and material are wasted. To overcome this problem, optimization of machining parameters is necessary.
Even though, there are several factors that affect the surface finish of a product, Speed, Feed, and Depth of cut are
found to be the most influencing factors on surface roughness. Alauddin et al. [1] have developed a surface
roughness model for milling 190BHN steel with Response Surface Methodology. In their study, the feed was
found to be the most dominating factor for surface roughness. Proper selection of cutter path strategies in pocket
milling saves machining time and cost. It also helps in improving surface quality [2]. In pocket milling, step over
and tool path strategy also play important roles in obtaining the required surface finish [3]. Aluminium and its
alloys are the commonly used materials in many fields of engineering. Their properties such as light weight, ease
of machinability, corrosion resistance etc., make them qualify for diversified applications. In molding industry,
surface finish is considered as one of the important parameters for manufacturing plastic components [4].
G1-continuous spiral path is employed by Held and Spielbergr[5], by using “POWERAPX” Package for the
generation of tool path in 2D pocket milling. Michel Bouard etal. [6] explained a new method for tool path
computation. In the current study, uniform cubic B-spline curves are applied to model surface roughness with an
optimization algorithm. Ali et al. [10] experimented on hardened material AISI H13 tool steel to predict surface
machined quality. Response Surface Methodology (RSM) Model was used to design the prediction model with
parameters generated using Central Composite Face (CCF) methods. Evolutionary algorithms also applied to
optimize the cutting conditions for better surface finish [6-8]. Effect of tool path strategies and pocket geometry on
Original Article
International Journal of Mechanical and Production
Engineering Research and Development IJMPERD)
ISSN (P): 2249-6890; ISSN (E): 2249-8001
Vol. 9, Issue 4, Aug 2019, 649-658
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