다파장 레이저빔을 이용한 알루미늄 합금의 용접특성

Abstract

Aluminum and aluminum alloys have high rate of lightness, recycling property and excellent specific strength. Fields using them have been widening because they could satisfy both energy reduction and high efficiency in manufactures production. But they have many problems on welding due to high thermal conductivity and reflectivity, so the study to solve these problems are proceeding actively around the world. This study was purposed to improve weldability and spread application range for aluminium alloys by using the unique property of aluminium which absorb high energy around 800㎛ wavelength and the higher temperature, the more absorbtion of laser beam on preheating by multi-wavelength laser beam(pulsed Nd:YAG laser + diode laser with 808㎛ wavelength). The favorable mechanical properties were acquired by the test results of strength, hardness and leak of weld metal which had reduced its defect like crack and so on.