Interfacial Control and Optimization for Friction Stir Spot Welding between Non-combustible Magnesium Alloy Sheet and Zinc-coated Steel Sheet

2014 Fiscal Year Final Research Report

• Project/Area Number: 23560865
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Material processing/treatments
• Research Institution: Okinawa National College of Technology (2012-2014); Osaka University (2011)
• Principal Investigator: TSUMURA Takuya 沖縄工業高等専門学校, 機械システム工学科, 准教授 (00283812)
• Research Collaborator: NAKATA Kazuhiro ; GUSHI Takashi ; SHINYA Nobuhide ; NASHIRO Yuki
• Project Period (FY): 2011-04-28 – 2015-03-31
• Keywords: 母材添加元素 / 三元共晶融解 / 金属間化合物

Outline of Final Research Achievements

Joints for metallographic observation and strength test were obtained by Friction Stir Spot Welding on certain conditions. Cross sections of the joint were observed, tensile shear test and cross tension test of the joint were evaluated, and fractured surface on the steel sheets were observed after the strength test.
Tensile shear strength of the non-combustible magnesium alloy and hot dip galvanizing steel sheet joint was higher than any other joints. Fracture was start at periphery of the joiningn area, and was progressed along with aluminum-iron intermetallic compound layer. Ternary eutectic of magnesium, aluminum and zinc was producted by the frictional heat, and the eutectic melt was discharged out of the joint interface, aluminum-iron intermetallic compound layer was formed. This compound layer help the tight-jointed.
It is made clear that change of tool shape and fixing plate produce an increased potential for improvement of tensile shear and cross tenslle strength.

Free Research Field

溶接・接合工学