Journal of the Korean Society of Manufacturing Technology Engineers (한국생산제조학회지)

The Korean Society of Manufacturing Technology Engineers (한국생산제조학회)
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Temperature and Mechanical Properties of Welded Joints Under Friction Stir Welding Conditions of Mg Alloy (AZ61)

Mg Alloy(AZ61) 마찰교반용접 조건에 따른 용접부의 온도와 기계적 특성변화

  • Lee, Woo Geun (New Transportation Systems Research Center, Korea Railroad Research Institute) ;
  • Kim, Jung Seok (New Transportation Systems Research Center, Korea Railroad Research Institute) ;
  • Sun, Seung-Ju (New Transportation Systems Research Center, Korea Railroad Research Institute)
  • Received : 2017.06.07
  • Accepted : 2017.08.01
  • Published : 2017.08.15
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Abstract

Friction stir welding was performed using six welding conditions to evaluate the mechanical properties and microstructure of the welded zone based on its temperature change in the extruded plate of magnesium alloy AZ61. The welded zone temperature was measured using a thermocouple, and the maximum temperature ranges for the advancing and retreating sides were approximately $210-315^{\circ}C$ and $254-339^{\circ}C$, respectively. Depending on the welding conditions, a temperature difference of more than $100^{\circ}C$ was observed. In addition, the maximum yield strength and maximum tensile strength of the welded component was 84.4% and 96.9%, respectively, of those of the base material. For the temperatures exceeding $300^{\circ}C$, oxidation defects occurred in the weld zone, which decreased the mechanical strength of the weld zone. The microstructure and texture confirmed that fracture occurred because of the grain size deviation of the welding tool and the severe anisotropy of the texture of the welded joints.

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References

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