CAJ | 학술논문

通过添加稀土元素Ce对0.2mm厚的GH4169高温合金进行微激光对接焊接，利用光学显微镜、扫描电镜、电子精密拉伸仪测试等分析方法，对比研究稀土元素对焊缝表面成形、接头显微组织及力学性能的影响。结果表明：在添加稀土元素的条件下焊接时，对焊接工艺参数进行正交试验优化，得出焊接最优工艺参数为脉冲功率17%、脉冲频率4.0Hz、脉冲宽度3.1 ms，此时焊接接头断裂在母材。焊接过程中，液态金属流动使稀土在熔池中均匀混合，获得了组织均匀的焊缝。稀土元素能够改变焊缝温度梯度，形成“梯形”状焊缝；同时，稀土元素能够降低接头的显微硬度，增强接头的韧性和塑性。
통과첨가희토원소Ce대0.2mm후적GH4169고온합금진행미격광대접한접，이용광학현미경、소묘전경、전자정밀랍신의측시등분석방법，대비연구희토원소대한봉표면성형、접두현미조직급역학성능적영향。결과표명：재첨가희토원소적조건하한접시，대한접공예삼수진행정교시험우화，득출한접최우공예삼수위맥충공솔17%、맥충빈솔4.0Hz、맥충관도3.1 ms，차시한접접두단렬재모재。한접과정중，액태금속류동사희토재용지중균균혼합，획득료조직균균적한봉。희토원소능구개변한봉온도제도，형성“제형”상한봉；동시，희토원소능구강저접두적현미경도，증강접두적인성화소성。
GH4169 superalloys with 0.2mm thickness are jointed by micro-laser welding with adding rare earth elements, and the influences of rare earth ele-ments on weld formation, the microstructure and mechani-cal properties of joints are studied by making use of optical microscopy, micro hardness tester, electronic precision stretching machine, and other analysis and detection meth-ods. The results show that the optimized processing param-eters with rare earth elements added is that the percentage of pulse power is 17%, pulse width is 3.1ms, and pulse frequency is 4.0Hz, at this moment the fracture of welded joint is at the base metal. During the welding process, the melted rare earth is fully uniformly mixed with the melted pool, and distributed weld zone structure is formed. Rare earth elements can change the temperature gradient of the weld zone, which induced to form trapezoidal shape weld zone. At the same time, welding joints with low hardness and good ductility and toughness welds are obtained attrib-uted to the rare earth elements.