连续铸挤无铅焊锡条SnCu0.7的微合金化及性能优化研究

【作者】 吕金梅；

【导师】 王华昆； 刘宝权；

【作者基本信息】 昆明理工大学 ， 材料工程（专业学位）， 2018， 硕士

【摘要】 锡具有质地柔软,熔点低,延展性好,可塑性强和无毒等优良特性,可与很多物质合成性质各异、用途广泛的合金。用于电子制造业中手工浸焊、波峰焊、自动焊接以及表面贴装等工艺中的锡铅焊料和无铅焊料占锡使用量的70%,由于铅及其化合物的剧毒性对环境和人类健康存在不可忽视的影响,使用无铅焊料代替锡铅焊料的需求越来越迫切,然而现有的无铅焊料在高温下使用时易产生氧化锡渣,影响焊接工艺和产品的质量,造成使用成本增高。本论文以SnCu0.7无铅焊料为研究对象,添加Ni?P?Ge元素优化焊料综合性能后,采用脱气-除渣-搅拌-抗氧化调质-连续铸造挤压成型关键工艺技术制备无铅焊锡条,使制备的连续铸挤无铅焊锡条SnCu0.7产品组织均匀、表面光亮、渣率低,综合性能好。研究结果表明:1、试验所加入的微量Ni?P?Ge对SnCu0.7无铅焊料的熔点影响不大;2、当Ni含量为0.05%时,焊料组织明显改进,SnCu0.7无铅焊料晶粒分布更加均匀,润湿性、抗氧化性提高;3、当Ni含量为0.05%?P含量为0.005%,SnCu0.7无铅焊料润湿性、抗氧化最好;4、Ni含量为0.05%?P含量为0.005%?Ge含量为0.009%时,润湿性、抗氧化、力学拉伸性能、金相显微组织最好;5、将合金成分为SnCu0.7Ni0.05P0.005Ge0.009的合金采用脱气-除渣-搅拌-抗氧化调质-连续铸造挤压成型关键工艺技术制备成无铅焊锡条后,与同合金成分的浇铸无铅焊锡条相比,产品组织均匀,一致性好,产品表面成镜面,动态渣率降低。更多还原

【Abstract】 Tin has many excellent characteristics,such as soft texture,low melting point,good ductility,strong plasticity and innocuity.It can be used to synthesize Tin base alloys with different properties and wide applications.About 70% of tin consumption is produced into tin lead solder and lead-free solder for the electronic manufacturing manual welding,wave-soldering,automatic welding and SMT process.Due to a higher toxicity,lead and its compounds have serious harm on the environment and human’s health needs.Lead-free solder become more and more urgent.However,it is easy to produce the oxidation slag when Sn-base lead free solder is used at high temperature.This will affect the quality of the welding process and products,resulting in a higher cost.The paper will focus on SnCu0.7 lead-free solder.The performances of solder are Optimized by adding Ni,P and Ge elements,and then the lead-free solders were prepared by degassing,deslagging,stirring antioxidation quenching,continuous casting and extrusion molding.The prepared SnCu0.7 lead-free solder products have uniform structure,bright surface,low slag rate and good comprehensive performances.The experimental results are shown as follows:1.Ni,P and Ge addition have little influence on the melting point of SnCu0.7lead-free solder.2.Adding 0.05wt%Ni,the microstructure of solder is improved obviously,and the grain distribution of SnCu0.7 lead-free solder is more uniform,and the wettability and oxidation resistance are improved.3.Adding 0.05 wt %Ni and 0.05 wt %P,the wettability and oxidation resistance of SnCu0.7 lead-free solder are the best.4.Adding Ni is 0.05wt%,0.005wt%P and 0.009wt%Ge,the wettability,oxidation resistance,mechanical tensile properties and metallographic microstructure are the best.5.Through degassing,deslagging,stirring antioxidation quenching and continuous casting,the SnCu0.7Ni0.05P0.005Ge0.009 alloy were prepared into lead free bar solder,which were compared with the solder bars prepared by casting products.The former has a uniform microstructure,a good consistency,a mirror surface and a lower dynamic slag rate.更多还原