(南昌航空大學(xué) 輕合金加工科學(xué)與技術(shù)國(guó)防重點(diǎn)學(xué)科實(shí)驗(yàn)室，南昌 330063)
摘 要: 采用低功率脈沖激光實(shí)現(xiàn)超薄QBe2.5鈹青銅與20#鋼異種材料的激光點(diǎn)焊，分析工藝參數(shù)對(duì)QBe2.5/20#鋼點(diǎn)焊接頭焊縫成形、力學(xué)性能和元素含量的影響規(guī)律以及顯微組織結(jié)構(gòu)。結(jié)果表明：隨著焊接功率和脈沖寬度的增大，接頭焊縫熔深H和熔寬B逐漸增大，且焊縫凹陷越加嚴(yán)重。當(dāng)焊接脈沖功率為20 W、焊接脈寬為8.0 ms時(shí)，其接頭抗拉強(qiáng)度可以達(dá)到98.36 N。接頭主要由富Cu的ε相和富Fe的α相混合組成，而焊縫中Fe元素含量與焊縫總深度L成正相關(guān)，Cu元素含量與下凹深度h成反相關(guān)。焊接功率和脈寬主要通過(guò)改變實(shí)際焊縫熔深H和凹陷深度h來(lái)改變接頭性能。
關(guān)鍵字: 異種材料；激光點(diǎn)焊；顯微組織；性能
（National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology, Nanchang Hangkong University, Nanchang 330063, China）
Abstract:The laser spot welding of ultra-thin QBe2.5 beryllium bronze and 20# steel dissimilar materials was realized using low power pulse laser, the influence of parameters on weld formation, mechanical properties and element content of QBe2.5/20 steel spot welding joints as well as its microstructure were analyzed. The results show that, with the increase of welding power and pulse width, the weld depth and width gradually increase, and the weld sag is more serious. When the pulse power is 20 W and the pulse width is 8.0 ms, the tensile shear of the joint can reach 98.36 N. The joint is mainly composed of a mixture of ε phase rich in Cu and α phase rich in Fe, however, the proportion of Fe in the weld is positively correlated with the depth of the weld, while the proportion of Cu is inversely correlated with the depth of the concave. Welding power and pulse width mainly change joint performance by changing weld penetration and sag depth.
Key words: dissimilar materials; laser spot welding; microstructure; joint performance
