Quarterly Journal of The Japan Welding Society 

About: Quarterly Journal of The Japan Welding Society is an academic journal published by Japan Welding Society. The journal publishes majorly in the area(s): Welding & Heat-affected zone. It has an ISSN identifier of 0288-4771. It is also open access. Over the lifetime, 3257 publications have been published receiving 11303 citations. The journal is also known as: Quarterly journal of the Japan Welding Society.

Friction stir welding

Abstract: PROBLEM TO BE SOLVED: To provide a joining method by which a joint part excellent in fatigue properties is formed when joining materials to be joined by a friction stir welding method. SOLUTION: The friction stir welding method enables the joint of two or more materials to be joined, by inserting a tool 6, which is provided with a columnar member having a pin-like probe projected from the end surface of the member, into materials 1, 2 to be joined while rotating the tool 6 and by moving the tool 6 while rotating it. In this friction stir welding method, a hollow part 7 is formed in parts of the materials to be joined, a member 5 is embeded in the hollow part, and the materials are welded by friction stirring. Since non-joint parts are not formed in the vicinity of the hollow part, notch effect is reduced so that a joint part excellent in fatigue properties is formed. COPYRIGHT: (C)2007,JPO&INPIT

Microstructure of Dissimilar Joint Interface of Magnesium Alloy and Aluminum Alloy by Friction Stir Welding

Abstract: Friction stir welding (FSW) shows significant advantages in the joining of aluminum alloys in recent years. In this paper, the feasibility of FSW for magnesium joints and magnesium to aluminum dissimilar joints was studied. Specimens were joined by FSW at the feed rate of 3.33-13.3 mm•s—1 and the tool rotational speed of 25 or 50 s—1. In the case of the butt welded magnesium alloy(AZ31), the average grain size in the stir zone is about 10μm that is smaller than that of in the parent metal. In the case of the dissimilar weld of magnesium alloy to aluminum alloy, mixing is limited and a more mechanical interlocking joint forms. However, the intermediate layer of about 2μm thickness is observed by TEM. Two kinds of phases are observed in the intermediate layer by the electron diffraction pattern. The electron diffraction suggests that one phase is Al12Mg17 intermetallic compound, while the other phase can not be defined. The mechanical properties of the dissimilar joint are inferior to those of the parent metals especially in the elongation because of the intermediate layer.

Friction-Stir-Welded Lap Joint of Aluminum to Zinc-Coated Steel

Abstract: This paper has dealt with the feasibility of friction-stir welding a zinc-coated steel plate to a pure aluminum plate in a lap joint configuration (the aluminum plate was top and the steel bottom). The friction stir welding was carried out at rotation speeds of 16.7-41.7 s-1 and travel speeds of 3.3-5 mm/s. It was found that the performance of the joint depended strongly on the depth of the pin tip of the FSW tool relative to the steel surface; when the pin depth did not reach the steel surface the joint showed quite weak fracture loads, while the penetration of the pin tip to a depth of 0.1 mm under the steel surface significantly increased the joint strength. The joint strength tended to increase with rotation speed and slightly decrease with the increase in the traveling speed. As compared with the similar joints of an aluminum to a steel without Zn-coating, joints of aluminum to the Zn-coated steel exhibited high strength at all bonding parameters employed in this investigation, which suggested the beneficial effect of the Zn coating on the bond strength.

Transient Thermal Stresses of Weld Heat-Affected Zone by Both-Ends-Fixed Bar Analogy

Abstract: Transient thermal stresses of weld heat-affected zones were evaluated by a rigid frame apparatus as shown in Fig. 1. Round bar specimens set into the rigid frame were put to thermal cycles by induction heating and transient thermal stresses were recorded on the oscillograph connected to the loadcell. Four kinds of steel of different mechanical and metallurgical properties were used. The types of applied thermal cycle were single thermal cycle, multi thermal cycles of constant peak temperature type, increasing- or decreasing- peak temperature type (see Figs. 11 a, b).Test results of the transient thermal stress as a function of temperature are shown in Figs. 6 thru 9, Figs. 12 thru 16, Figs. 18 and 19. Residual stresses as a function of peak temperature applied are shown in Fig. 10 for single thermal cycles and in Fig. 17 for multi thermal cycles. The transient thermal stresses and residual stresses are influenced by the mechanical and metallurgical properties of steels used.Analysis of mechanical strains during thermal cycles was made using a connected bar-spring model as illustrated in Fig.2 b and a long rectangular plate as in Fig. 23 on they-axis of which an instantaneous plane heat source was applied. The analysis revealed the difference in mechanical strains between the model and the rectangular plate. The transient thermal stresses or elastic strains in plastic zones of the rectangular plate were approximately estimated by both-ends-fixed bar analogy.

Behavior of Oxide during Friction Stir Welding of Aluminum Alloy and Its Influence on Mechanical Properties.

Abstract: In the stirred zone of friction-stir welds of an aluminum alloy 6N01 plate (formed through extrusion), a zigzag bond line was observed after etching by an aqueous solution of 10% NaOH, when the revolution pitch (tool traveling speed/rotation rate) was greater than a critical value. SEM and TEM observations revealed that the bond line consisted mainly of particular inclusions 0.01-0.2 ƒÊm in size. The inclusion was identified as complex oxide involving Al, Mg, and Si based on EDX analyses. The inclusion can be considered to originate from the oxide film that was formed on the plate surface during the extrusion