Manufacturing Technology Today

S. B. Mahagaonkar ¹, P. K. Brahmankar ², C. Y. Seemikeri ¹

Affiliations
1 Dr. BATU, Lonere (MS), IN
2 Mech. Engg. Dept., Dr. BATU, Lonere (MS), IN

Abstract

An engineered shot peened surface has potential surface applications. Peaks of the shot peening dimples helps to lower coefficient of friction and in some applications "valleys" of the peening dimples offer lubricant retentions that are not present in a smooth surface. Wear resistance of the component can be increased by controlling surface roughness, whereas by controlling surface hardness the fatigue life will increase due to the increase in cold work. Depending on the applicability of the component for fatigue or wear condition, the shot peened textured surface can be controlled, by setting the peening parameters based on the effect of individual, as well as interaction effect of the parameters. In this paper, full factorial Taguchi's 2^k DOE technique was used to analyze surface roughness and micro hardness, on the specimens made of medium carbon steel En8, using air blast type shot peening machine. This investigation examines the respective effects of influencing parameters such as pressure, shot size and the exposure time at their two different levels on surface roughness and hardness. After going through confirmation test the analysis reveals the right combination of the parameters for better process control. This technique sets an example for the other applications in the industries to reduce the performance variation and to improve quality, performance, reliability and profits.

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C. Y. Seemikeri ¹, P. K. Brahmankar ¹, S. B. Mahagaonkar ¹

Affiliations
1 Dr. Babasaheb Ambedkar Technological University [Dr. B.A.T.U.], Lonere-402103 (M.S.), IN

Abstract

Results of the latest research indicate that the life and the reliability of machine components are affected greatly by the varieties of surface enhancement technologies applied and also by the sequence and conditions of their application. Low Plasticity Burnishing (LPB) is a new method of surface enhancement, which can provide deep stable surface compression for improved surface integrity characteristics. The present study focuses only on the surface roughness and surface micro-hardness aspects using full factorial design of experiments. After studying the effects of various parameters of the LPB process on AISI 316, favourable and optimum conditions could be predicted and tailored for different requirements. The parameters that have greater influence on the surface roughness in the decreasing order of importance are number of passes, ball diameter, pressure, and speed, whereas ball diameter, speed, pressure, and number of passes is the order for the surface hardness. In order to minimize the roughness of the surface it is advisable to set the speed, pressure, number of passes at high level and ball diameter at low level looking into the strong interaction that pressure is involved with speed and number of passes. After analysing the interaction effects of parameters on the surface hardness, it is advisable to set the speed, number of passes at lower level and ball diameter, burnishing pressure at higher level to maximize the surface hardness.

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C. Y. Seemikeri ¹, P. K. Brahmankar ², S. B. Mahagaonkar ¹

Affiliations
1 Dr B.A.T.U., Lonere, IN
2 Mechanical Engg. Dept., Dr. Babasaheb Ambedkar Technological University [Dr B.A.T.U.] Lonere - 402103 (M.S), IN

Abstract

A new field 'engineered surfaces' would be more effective and economic route to successful manufacture. There are a number of methods of surface treatment or enhancement that can produce required surface roughness, surface hardness, and residual compressive stresses into the surface of components. Low Plasticity Burnishing (LPB) is a novel method of surface enhancement, which raises the burnishing to next level of sophistication and that can provide deep stable surface compression for improved surface Integrity characteristics. LPB smoothes surface asperities leaving an improved surface finish apart from inducing surface hardness. This technology could be very useful to Defence applications since it has the potential to improve many surface characteristics such as ultimate tensile strength, low and high cycle fatigue strength and, foreign object damage tolerance, corrosion resistance, out of roundness and straightness, wear resistance etc. However, the present study was concentrated only on the surface roughness and surface micro hardness aspects. After studying the various parameters of the Low plasticity burnishing process, which affect considerably the surface roughness and surface hardness of AISI1045, the favourable and optimum conditions could be predicted and tailored for different materials for different requirements of finish/surface hardness and economy of process. Surface roughness up to 0.5 microns and surface hardness of 421HV was achieved forAISI1045, by this process. The process can be applied to critical components effectively, as the LPB process today has significant process cycle time advantages. This cycle time advantage and lower capital cost translate to substantially lower cost for LPB. Additional cost reduction will be realized by introducing proven high speed machining concepts into the LPB process.

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