Zhang Jian-zhong, Huang Qing-feng, Jiang Wei-dong, Li Quan, Yu Jin-xing
Department of Prosthodontics, Ninth People's Hospital, School of Stomatology, Shanghai Second Medical University, Shanghai 200011, China.
Shanghai Kou Qiang Yi Xue. 2004 Oct;13(5):416-20.
To investigate the effect of different irradiation power on the mechanical properties of laser-welded joints.
The standard tensile test and three-point bending test rods made from Co-Cr and Ni-Cr alloy were laser-welded with different irradiation powers. Then the tensile rods were tested for the ultimate tensile strength (UTS), and the bending rods for the ultimate bending strength (UBS). The tensile fracture surface was examined by scanning electron microscopy (SEM). Metallurgical analysis and microhardness test were also performed on polished longitudinal sectioned samples.
For Co-Cr alloy, greater irradiation power resulted in greater UTS, minor UBS. For Ni-Cr alloy, there was no significant difference of UTS and UBS between the four groups. SEM and metallurgical examination showed that the welded zone exhibited more gas pores and cracks as the irradiation power increased. Microhardness test showed that hardness increased toward the center of the welded zone and as the irradiation power increased, the range of hardness increased was expanded.
The optimal laser irradiation power was the key to achieved superior mechanical properties joints.
研究不同辐照功率对激光焊接接头力学性能的影响。
采用不同辐照功率对由钴铬合金和镍铬合金制成的标准拉伸试验棒和三点弯曲试验棒进行激光焊接。然后对拉伸试验棒测试其极限抗拉强度（UTS），对弯曲试验棒测试其极限抗弯强度（UBS）。通过扫描电子显微镜（SEM）检查拉伸断口表面。还对抛光后的纵向切片样品进行了金相分析和显微硬度测试。
对于钴铬合金，辐照功率越大，UTS越大，UBS越小。对于镍铬合金，四组之间的UTS和UBS无显著差异。SEM和金相检查表明，随着辐照功率增加，焊接区出现更多气孔和裂纹。显微硬度测试表明，硬度向焊接区中心增加，且随着辐照功率增加，硬度增加的范围扩大。
最佳激光辐照功率是获得具有优异力学性能接头的关键。
