【作者】 党波；

【导师】 徐锦锋；

【作者基本信息】 西安理工大学 ， 材料科学与工程， 2010， 硕士

【摘要】 本文针对B-Ag72Cu28钎料银含量高,不利于资源的可持续发展,设计出一种高性能低银钎料应用于电真空器件中,力图取代B-Ag72Cu28。采用急冷快速凝固技术制备出厚度为15-60μm、宽为3-5mm的Ag (40-45wt%)-Cu-Sn-Ni钎料合金箔,分析钎料合金的熔点、润湿性、电学、力学性能和钎焊工艺,研究合金元素Sn、Ni对钎料性能的影响规律,并对钎接接头力学性能进行表征。结果表明：常规凝固Ag-Cu-Sn钎料合金微观组织均由面心立方的(Ag)、α-Cu和少量的Cu13.7Sn三相组成；凝固组织中,粗大枝晶为先析相α-Cu,在枝晶间弥散分布着白、灰相间的((Ag)+α-Cu)共晶；急冷Ag-Cu-Sn-Ni钎料合金微观组织由面心立方的(Ag)、α-Cu和少量的Cu13.7Sn、Ni17Sn3四相组成,急冷钎料合金组织细小均匀,以等轴晶为特征。随着Sn含量的增加,(Ag-Cu) 100-xSnx钎料合金箔的固、液相线温度降低,Ts=590-616℃、T1=615-622℃,熔化温度区间△T增大；合金箔的电阻升高,抗拉强度增高,σb=280-360MPa,伸长率减小,δ=2.8-5%。随着Ni含量的增加,(Ag-Cu-Sn)100-xNix钎料合金箔的固、液相线温度增加,Ts=690-718℃、T1=715-727℃,温度区间△T减小；合金箔的抗拉强度增高,σb=345-515MPa,伸长率减小,δ=3-6%。在800℃保温30s条件下,急冷(Ag-Cu-Sn)100-xNix钎料合金对可伐合金的润湿效果良好,且随着Ni含量的增加,铺展面积减小,S=0.8634-1.4033cm2,润湿角增大,θ=9.4-23.3°；对比试验结果表明,急冷合金箔在可伐合金上的润湿性明显优于常规凝固合金。采用Ag42CuSn10Ni0.4钎料合金箔真空高频感应钎焊0Cr18Ni9Nb,获得接头组织主要以(Ag)和α-Cu固溶体为主相,少量Cu13.7Sn相、Ni17Sn3相和γ-Fe相分布其中。在加热电流为25A,升温时间15s,保温时间10s工艺条件下,钎接接头的抗拉强度高达σb=189.29MPa。更多还原

【Abstract】 In this paper, for the more silver content in B-Ag72Cu28 brazing filler used to the vacuum devices have confined sustainable development of noble metal resources. It’s worthy of designing a new silver based filler with lower silver content to substitute B-Ag72Cu28 in order to save product cost. Ag(40-45wt%)-Cu-Sn-Ni alloy foil with the size of 15-60μm thickness and 3-5mm width were prepared by rapid solidified technology. The solidus and liquidus temperature, wettability, electrical resistivity performance, mechanical properties of brazing alloys and brazing process were analysed, and the stannum and nickel elements influence on properties of brazing filler were studied, meanwhile, the mechanical properties of joint were also tested and measured. The results indicated as follows:The microstructure of regular solidified Ag-Cu-Sn alloy are composed of face-centered cubic (Ag)、α-Cu and little Cu13.7Sn; in the structure of regular solidified alloy, rough dendrite isα-Cu phase appearing first, and the white and gray alternate ((Ag)+α-Cu) eutectic distribute in the interdendritic space. Ag-Cu-Sn-Ni alloy foil is constituted of face-centered cubic (Ag)、α-Cu and little Cu13.7Sn、Ni17Sn3, the microstructure of rapid solidifying alloy is fine and homogeneous equiaxed crystal.With stannum content in(Ag-Cu)100-xSnx(x=12.23,12.94,13.65)increasing, temperature of solidus and liquidus of alloy foil becomes lower, the value range of which are Ts=590-616℃and Tl=615-622℃respectively, temperature interval△T is bigger; Electric resistivity and tensile strength of alloy foil are larger, but elongation ratio is smaller, the value range of which areσb=280-360MPa andδ=2.8-5% respectively. With nickel content in (Ag-Cu-Sn)100-xNix (x=0.4,0.6,0.8,1.0) increasing, temperature of solidus and liquidus of alloy foil becomes higher, the value of which are Ts=690-718℃and Tl=715-727℃respectively, but temperature interval△T is smaller; the tensile strength of alloy foils becomes stronger but elongation ratio is smaller, the value range of which areσb=345-515MPa andδ=3-6% respectively. In the conditions of heating up to 800℃and holding for 30s, (Ag-Cu-Sn)100-xNix brazing alloy foil displays good wettability on Kovar alloy, and with the nickel content increasing, spread areas are smaller gradually but the wetting angle is bigger, the value ranges are S=0.8634-1.4033cm2 andθ=9.4-23.3°respectively; otherwise, the brazing alloy have better wettability on Kovar by rapid solidified technology than regular solidified technology.Using Ag42CuSn10Ni0.4 brazing alloy foil brazed the stainless steel by high-frequency induction brazing technology, the microstructure of brazing seam is mainly made up of (Ag)、α-Cu, and, little Cu13.7Sn、Ni17Sn13 andγ-Fe phases distributed into them; the value of tensile strength of joint is up to 189.29MPa, under the conditions of heating time for 15s and holding for 10s and the heating current is 25A during experimental process.更多还原