• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.2
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• pp.73-78
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• 2001

In this study, the friction weldability and properties of inconel alloy(IN738LC) to stainless steel (STS304) was investigat-ed. Upset length increased according to increment of friction pressure and time. The tensile strength of the friction weld-ing reached 85% of the STS304 base metal strength under the conditions of 8 sec friction time, 50MPa friction pressure and 150 MPa upset pressure. From the result of fracture surface analysis, IN738LC section can be joined with STS 304 materials in shape of a convex lens. Also, the temperature of welded interface was measured with k-type thermocouple. Finally the plastic flow confirmed at the welded interface STS304 by micro test.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.6
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• pp.75-81
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• 2012

Dissimilar material friction welding such as STD11 and SCM440, we are considering of such things as strength and tenacity of welding interface, which consist of friction welding rotation frequency, friction heating pressure, upset forging-pressure, friction heating time, and upset forging-pressure time. From the study, obtaining the interrelationship between welding condition and quality(toughness, tenacity), we can set the best range of welding condition. while performing acoustic emission examination for the nondestructive evaluation, we can deduce the interrelationship among total acoustic emission counts, friction welding variable, and quality during friction welding, which can solve the manufacturing difficulty and enhance the economic value.

• Proceedings of the KWS Conference
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• 1995.10a
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• pp.165-169
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• 1995

This paper deals with determining the proper friction welding condition and analyzing mechanical in of friction welded joints of sintered carbide tool materials (SKNM50 for the blade part of press punch) to alloy steel (SCM440 for the shank part of press punch), the alloy steel to aluminum(A6061 for the interlayer material between the blade part and the shank) and sintered carbide tool materials to aluminum. And also acoustic emission test will be carried out during fiction welding to evaluate the weld quality.

• Proceedings of the KWS Conference
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• 1995.10a
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• pp.101-104
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• 1995

This paper deals with the development of fundamental design and manufacturing technique of hydraulic valve spool by optimizing of friction welding, the development of in-process real-time weld quality evaluation technique by acoustic emission and the evaluation of the mechanical properties and the fatigue life about the bar-to-bar dissimilar friction welded hydraulic valve spool steels.

• Journal of Ocean Engineering and Technology
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• v.23 no.6
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• pp.105-110
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• 2009

The objective of this paper is to investigate the statistical properties of Vickers hardness (HV) for friction welded parts in a Ni-based super alloy (Alloy718). In the case of post weld heat treatment (PWHT) parts, hardness tests were repeated for three different applied loads, 100, 200, and 300 g, with a duration time of 10 seconds. The arithmetic means of the Vickers hardness in heat affected zone (HAZ) materials were smaller than those of the base metal (BM) in all of the applied loads. The coefficient of variation (COV) for the BM and HAZ decreased by increasing the applied load. The probability distribution of the Vickers hardness followed the Weibull distribution well. The distribution of the Vickers hardness was not found to be symmetric. The shape parameter and scale parameter increased by increasing the applied load at both the BM and HAZ.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1747-1751
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• 2003

The paper shows properties such as vickers hardness, yielding and ultimate stresses for the weld zone of the butt and the lap jointed specimens, and compare maximum loads, stress-strain curves, deformation appearance after guided bending test and fracture appearance for butt and lap jointed specimens. The research in this experiment also shows the weldability of the butt joint specimen is better than that of the lap joint specimen using FSW with $2mm^{t}$ aluminum alloy sheet in milling machine.

• Proceedings of the KWS Conference
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• 2007.11a
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• pp.328-331
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• 2007

It was carried out to evaluate microstructure and mechanical properties of friction stir welded(FSW) on magnesium alloys. Two types magnesium alloy was used in this work, AZ31 wrought and AZ91 cast magnesium alloy. Microstructure near the weld zone showed general weld structures such as stir zone(SZ), thermo-mechanically affected zone(TMAZ) and heat affected zone(HAZ). In the AZ91 alloy, the SZ had a fine grain size and $\beta$ phase particles which were well distributed in matrix. It was characterized to redistribute by partial or full re-solution of the $\beta$ phase which is coarse in base metal during FSW processing. The hardness of the SZ slightly increase than the base metal in AZ31 Mg alloy.

• Journal of Welding and Joining
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• v.4 no.3
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• pp.32-42
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• 1986

In this study, the influence of carbon equivalents on friction welds of dissimilar steels was investigated. Four types of carbon steels with 10mm diameter were welded to a high-speed tool steel SKH 9. Main experimental results could be summarized as follows (1) Under constant friction pressure, the friction time increased almost linearly with the increasing burn-off length, while the forge length decreased almost linearly. (2) The maximum hardness in carbon steels increased almost linearly with the increasing carbon equivalent, but was much lower than that in the high speed steel. (3) After quenching and tempering of dissimilar steel friction welds, the hardness in carbon steel weldments became similar as that in the base metal, while the hardness in SKH 9 weld was still higher that of the base metal. (4) Relative movement in the friction phae occurred not at the interface of the weldments, but in the high speed steed steel near the interface. (5) For considered material combinations and welding parameters, most of fractures in tension and twisting tests occurred in the base metal. And welds with so high strength could produced in a wide range of welding parameters.

• Journal of Power System Engineering
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• v.4 no.4
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• pp.54-58
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• 2000

The complete joining method for dissimilar hot die punch materials and its real-time evaluation method are not available at present. Brazing method has been used for joining them, but it is known that the welded joint by the brazing has the lower bonding efficiency and reliability than the diffusion welding. The friction welding with a diffusion mechanism in bonding was applied in this study. So, this work was carried out to determine the optimal friction welding conditions and to analyze mechanical properties of friction welded joints of hot die punch materials (STD61 for the blade part of hot die punch) to alloy steel (SCM440 for the shank part of hot die punch) such as plunger. In addition, acoustic emission test was carried out during friction welding to evaluate the weld quality.

• Journal of the Korean Society of Safety
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• v.16 no.3
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• pp.19-25
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• 2001

The friction-welding SM25C is a substitute for the suing steel that is utilized in the machinery, airplane, and automobile, ok. This substitution would provide reduction of material and weight of welding parts. From the result we found that the strength of the friction welded joint was 529-617MPa and the toughness 1.2 times higher than that of the base metal. The optimal condition of friction welding was found as follows : n=2000rpm, $P_1$=68㎫, $P_2$=137MPa, $t_2$=2sec, $t_1$=2-4sec, Considering the strength, the hardness, and the reduction of area in the friction welding, the fiction welding using SUP9A and SM25C was found to cause no problem in on-the-job application.