OCTOBER 19-20, 2012 - YMCA University of Science & Technology

Proceedings of the National Conference on
Trends and Advances in Mechanical Engineering,
YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012
OPTIMIZING SURFACE ROUGHNESS OF HIGH DIE STEEL H13 IN
CNC MILLING USING TAGUCHI TECHNIQUE:
Mandeep Chahal 1 , Vikram Singh 2 , Rohit Garg 3 , Sudhir Kumar 4
1
Asstt. Professor, Deptt. of Mech. Engg., HCTM, Kaithal (Haryana), India. email: mandeepchahal17@yahoo.in
2 Associate Professor, Deptt. of Mech. Engg., YMCAUST, Faridabad, India. email: singhvikram77@gmail.com
3 Principal, Indus Institute of Engineering& Technology, Jind (Haryana), India email: rohit_garg123@yahoo.com
4 Professor, Deptt. of Mech. Engg., NIET, Greater Noida(U.P), India email: s_k_tomar02@yahoo.com
Abstract
This experiment gives the effect of different machining parameters (cutting speed, feed, and depth of cut) on
Surface Roughness in end milling. Taguchi technique is being used for the various calculations. The study was
conducted in machining operation for hardened die steel H-13. The processing of the job was done by solid
carbide four flute end-mill tool under finishing conditions. L-9 standard orthogonal array is used for calculation
of no. of variables and no. of levels. Signal to Noise Ratio and ANOVA techniques are used to draw the graphs
and come to the results.
Keywords: CNC Milling, Surface Roughness (SR), ANOVA, S/N Ratio
1. Introduction & Literature Review
With the more precise demands of modern engineering products, the control of surface texture together with
dimensional accuracy has become more important. This experimental investigation outlines the Taguchi
optimization methodology, which is applied to optimize machining parameters in end milling operation. The
experiment is conducted on hot die steel H 13. The processing of the job is done by solid carbide four flute endmill
tools under finishing conditions. The machining parameters evaluated are cutting speed, feed rate and depth
of cut. The experiments are conducted by using L-9 orthogonal array as suggested by Taguchi. Signal-to-Noise
(S/N) ratio and Analysis of Variance (ANOVA) is employed to analyze the effect of milling parameters on
surface roughness.Milling is a process of producing flat and complex shapes with the use of multi-tooth cutting
tool, which is called a milling cutter and the cutting edges are called teeth.
2. Experimental Methodology
Dr. Genichi Taguchi gives three philosophies to improve the product quality.
1. Quality should be designed into a product, not inspected into it. Quality is designed into a process through
system design, parameter design, and tolerance design. Parameter design, which will be the focus of this article,
is performed by determining what process parameters most affect the product and then designing them to give a
specified target quality of product. Quality "inspected into" a product means that the product is produced at
random quality levels and those too far from the mean are simply thrown out.
2. Quality is best achieved by minimizing the deviation from a target. The product should be designed so that it
is immune to uncontrollable environmental factors. In other words, the signal (product quality) to noise
(uncontrollable factors) ratio should be high.
3. The cost of quality should be measured as a function of deviation from the standard and the losses should be
measured system wide. This is the concept of the loss function, or the overall loss incurred upon the customer
and society from a product of poor quality. Because the producer is also a member of society and because
customer dissatisfaction will discourage future patronage, this cost to customer and society will come back to the
producer.
3. Experimental Setup and Process Parameters Selected
Work piece material
Hot die steel H13 in the plate form of size 280x200x32 mm 3 have been used to carry out experiments. H13 die
steel have been chosen because of high hardness, excellent wear resistance, hot toughness and good thermal
shock resistance properties. The chemical composition of H13 die steel is given in table-1.
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