CMT电弧增材制造Cu-Ni-Al-Mn-Fe铝青铜合金微观组织性能研究  

Microstructure of Cu-Ni-Al-Mn-Fe Copper Alloy Made by of CMT Arc Additive Manufacturing Technology

作　　者：陈伟[1] 黄龙彪 陈玉华[1] 朱嘉文 陈超[1] 孙松伟 CHEN Wei;HUANG Long-biao;CHEN Yu-hua;ZHU Jia-wen;CHEN Chao;SUN Song-wei(Department of Welding Engineering,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学焊接工程系,南昌330036

出　　处：《精密成形工程》2018年第5期81-87,共7页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(51565040)

摘　　要：目的研究冷金属过渡技术(Cold metal transfer,简称CMT)增材制造Cu-Ni-Al-Mn-Fe铝青铜合金的微观组织成形规律。方法采用CMT电弧增材的方式制备了Cu-Ni-Al-Mn-Fe铝青铜合金的薄壁试样件,研究了试样件在不同位置、不同方向的微观组织。结果 CMT电弧增材制造Cu-Ni-Al-Mn-Fe铝青铜合金的微观组织分为3个区域,前3层的不稳定区域主要是由基材树枝晶到柱状晶的转变区域;第3层到最后一层的稳定区域主要是外延生长的柱状晶区;在最后一层靠近空气侧约360μm厚度范围内,出现转向枝晶。交替往复电弧增材的Cu-Ni-Al-Mn-Fe铝青铜合金,在每层顶部均会形成转向枝晶,但随后新一层电弧增材的熔池会熔化顶部形成的转向枝晶,最终在微观组织形貌上表现出柱状晶外延生长的形式。结论通过控制合适工艺参数,可以获得致密无缺陷的CMT电弧增材制造Cu-Ni-Al-Mn-Fe铝青铜合金薄壁试样,在试样的稳定区域,微观组织是外延生长的柱状晶,柱状晶的晶界上Al,Ni,Mn元素产生富集现象,质量分数高于平均值。在柱状晶的晶内,Cu元素高于均值,而Al,Ni,Mn元素质量分数均低于均值,这与柱状晶的形核顺序有关。The paper aims to study the microstructure evolution of Cu-Ni-Al-Mn-Fe aluminum bronze alloys produced by arc additive manufacturing technology based on cold metal transfer(CMT).Thin-walled specimens of Cu-Ni-Al-Mn-Fe aluminum bronze alloy were fabricated by CMT arc additive manufacturing technology.The microstructures of specimens in different positions and different directions were studied.The microstructure of Cu-Ni-Al-Mn-Fe aluminum bronze alloy produced by CMT additive manufacturing was divided into three regions,the first three layers of unstable region,mainly from the transition zone of dendrite to columnar crystal.The stable area from the third layer to the last layer was mainly an epitaxially grown columnar crystal region.Turning dendrites occurred within a thickness of about 360μm in the final layer near the air side.Cu-Ni-Al-Mn-Fe aluminum bronze alloys with alternating reciprocating additive manufacturing would form diverted dendrites at the top of each layer,but then a new layer of melt pool would re-melt the turning dendrites formed at the top.The morphology of the columnar crystal epitaxial growth was finally manifested in the microstructure.Dense and defect-free Cu-Ni-Al-Mn-Fe aluminum bronze alloy thin-walled specimens could be fabricated by CMT arc additive manufacturing technology through controlling appropriate process parameters.In the stable region of the prepared specimens,the morphology of the columnar crystal microstructure shows epitaxial growth.On columnar crystal grain boundaries,Al,Ni and Mn show element enrichment.The mass fraction is higher than the average.In columnar crystals,Cu is above the mean and Al,Ni and Mn are all lower than the mean,which is related to the nucleation order of columnar crystals.

关 键 词：Cu-Ni-Al-Mn-Fe铝青铜合金 CMT 增材制造 微观组织 

分 类 号：TG146.11[一般工业技术—材料科学与工程]