ANALYSIS AND OPTIMIZATION OF HEAT TREATMENT PARAMETERS USING TAGUCHI S ROBUST DESIGN METHODOLOGY TO A PROCESS A CASE STUDY

Abstract

Different techniques are used by viable manufacturing industries / set ups for the new product or process by production facilities to produce good quality products in less time by creating the novel manufacturing parameters or processes. To innovate the manufacturing process, great efforts are put in by technical manpower which is involved in the production to optimize parameters. It consumes a lot of time as well as effort. It is based on the hit and trial method and results in the wastage of resources to accomplish the desired task. Production setups are continuously working on TQM. Various TQM tools and techniques are available and being implemented on variety of works in different organizations. One of the easy, effective and economic methodology is available in the shape of Taguchi method. This method not only reduces the variability among the processes and products but it also helps in the selection of best parameters which provide the output very close to the ideal goal. Taguchi methods are statistical approaches to the robust design of the products. They are mainly used in parametric and tolerance design. Parametric design is the observation of the effects of parameter values on the performance of the system and the selection of suitable values to be assigned to the parameters. It determines what combination of parameters (dimensions, tolerances, speeds, weights, values, etc.) should be used to optimize system performance with the most consistency, under the influence of difficult to control factors such as ambient conditions. An effort will be made in this work for the clarification of Taguchi methods through a structured approach in literature review. After development of understanding of the Taguchi methods, Aluminum Alloy (Al7075) has been selected to evaluate the influence of various parameters related to the heat treatment that how they effect Al7075 work pieces during experimentation and testing with reference to their mechanical properties. Mechanical properties taken into account in this investigation were UTS, YS and HV of Al7075 as a result of heat treatment. The best parameters were found with the use of OA L9 (34) which has been designed by Taguchi. Values of UTS, YS and HV were checked in the experimental work. Improvement in mechanical properties of Al7075 along with maintaining the product’s quality was the prime focus of this Ultimate Tensile Strength (UTS) of the workpiece was regarded as a quality characteristic research. alongwith YS and HV. The Al7075 specimens were prepared based on the job loaded in batch production. Standard ASTM B918 was used to evaluate the mechanical properties of Al7075. Certain software are present for the implementation of the Taguchi methods. For determination of ratio between noise and signal after putting the variables in the matrix of L9 (34), Minitab15.0 has been utilized. Influence of all factors in terms of percentage was measured by the use of Analysis of Variance feature of Minitab software. Total experimental runs which have been executed were nine. In these nine experimental runs there is no duplication of level settings. After execution of experiments the best combination of levels of factors which have been selected and recommended for best results are Temperature of Pre-aging is 120 oC, Time of Pre-aging is 8 hrs, Temperature of Re-aging is 150 oC and Time of Re-aging is 3 hrs.