• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.7
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• pp.1581-1589
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• 1995

The feasibility of using AE for detecting contact and slip between a workpiece and an end effector has been tested. Specifically, the relationship between the contact and slip motion and the characteristics of the AE signal is theoretically and experimentally investigated. The experimental results manifest that the high sensitivity of AE signal to the contact and slip makes it a good alternative as a robot tactile sensor.

• Journal of Welding and Joining
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• v.13 no.4
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• pp.103-112
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• 1995

This study was performed to optimize friction welding conditions of Cr-Mo steel bars used for hydraulic of pneumatic valve spools and to realize the real-time evaluation of weld quality by acoustic emission method. SNCM220, SCM435, SCAM645, and SCM415 steel bars were tested to find optimum conditions of friction welding. Auantitative equations which exhibit the relations of tensile strength, elongation, reduction of area and energy absorption with friction heating time were obtained by the experiment. Acoustic emission was also performed in the friction weldig process, and the real-time evaluation was enabled to find the optimum range of weld strength. Finally, the strength and toughness of welded joints were interpreted by the sem analysis of tensile fracture surfaces.

• Proceedings of the KWS Conference
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• 1995.10a
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• pp.3-20
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• 1995

Development of Real-Time Quality Evaluation of Friction Welding by Acousitc Emission : Report 1 ABSTRACT : According as the friction welding has been increasingly applied in manufacturing various machine components because of its significant economic and technical advantages, one of the important concerns is the reliable quality monitoring method for a good weld quality with both joint strength and toughness in the process of its production. However no reliable nondestructive test method is available at present to determine the weld quality particularly in process of production. So this paper presents an experimental examination and quantitative analysis for the real-time evaluation of friction weld quality by acoustic emission, as a new approach which attempts finally to develop an on-line quality monitoring system design for friction welds using AE techniques. As one of the important results, it was confirmed, through this study, that AE techniques can be reliably applied to evaluating the friction weld qualify with 100% joint strength, as the cumulative AE counts occurring during welding period were quantitatively correlated with reliability at 95% confidence level to the joint strength of welds. Real-Time Evaluation of Automatic Production Quality Control for Friction Welding Machine : Report 2 Abstract : Both in-process quality control and high reliability of the weld is one of the major concerns in applying friction welding to the economical and qualified mass-production. No reliable nondestructive monitoring method is available at present to determine the real-time evaluation of automatic production quality control for friction welding machine. This paper, so that, presents the experimental examinations and statistical quantitative analysis of the correlation between the initial cumulative counts of acoustic emission(AE) occurring during plastic deformation period of the welding and the tensile strength of the welded joints as well as the various welding variables, as a new approach which attempts finally to develop an on-line (or real-time) quality monitoring system and a program for the process of real-time friction welding quality evaluation by initial AE cumulative counts. As one of the important results, it was well confirmed that the initial AE cumulative counts were quantitatively and cubically correlated with reliability of 95% confidence level to the joint strength of the welds, bar-to-bar (SCM4 to SUM31, SCM4 to SUM24L) and that an AE technique using initial AE counts can be reliably applied to real-time strength evaluation of the welded joints, and that such a program of the system was well developed resulting in practical possibility of real-time quality control more than 100% joint efficiency showing good weld with no micro-structural defects.