Kazuo Matsuzawa

Comparison between Simple Seam Welding and Adjacent Parallel Seam Welding by Magnetic Pulse Sheet-Welding Method

This paper describes the comparison between simple seam welding and adjacent parallel seam welding by a magnetic pulse welding method for Al-Al sheets. In the case of the parallel seam welding, the sheets collided at high speed in two parallel along a narrow central part of a one-turn flat coil. The central part had two parallel upper parts. The width of the central part was same as that of the simple seam welding. The increase of the parallel seam-weld zones was more than double in total in comparison with the simple seam-weld zones. Two inside parallel seam-weld zones were connected each other with a small cavity.

Special issue "Magnesium and magnesium alloys". Effect of drill's width of margin on drilling of AZ31 magnesium alloy bar.

Effects of drills width of margin and back taper on the deep drilling of AZ31 magnesium alloy bars have been investigated. The reduction of drills width of margin produced remarkable effects such as the improved chip discharge, the reduced cutting resistance, the significantly improved machined surface and the restrained outlet burr creation. These effects enabled the drilling into deeper parts easily. The similar effect was also obtained by giving back taper to a drill. To conclude, the reduction of drills width of margin as well as back taper given to a drill are extremely effective to improve both the safety in drilling and drills tool life.