P元素对Sn-0.3Ag-0.7Cu钎料抗氧化性、润湿性以及显微组织的影响

Effect of P element on oxidation resistance,wettability and microstructure of Sn-0.3Ag-0.7Cu solder

为改善Sn-0.3Ag-0.7Cu钎料抗氧化性和润湿性差的问题,在钎料中添加了P元素,研究了微量P元素对Sn-0.3Ag-0.7Cu钎料抗氧化性、润湿性以及显微组织的影响。制备了含不同质量分数P元素的Sn-0.3Ag-0.7Cu-xP(x=0%,0.005%,0.010%,0.015%,0.020%)钎料。以实验的方式测试了钎料的抗氧化性以及润湿性,并使用扫描电镜(SEM)和能谱仪(EDS)观察了显微组织。结果表明:随着P含量的增加,钎料的抗氧化性和润湿性显著提高。当P含量达到0.020%时,与不添加P元素的钎料相比,在250℃保温30 min后的氧化渣质量由2.25 g减少到0.79 g。此时,钎料的铺展面积和润湿力也达到最大,分别为65.74 mm^(2)和5.04 mN,润湿时间为0.96 s。添加微量P元素未改变钎料的相组成,其显微组织主要由β-Sn、Ag_(3)Sn与Cu_(6)Sn_(5)三种相构成。随着P含量的增加,Ag_(3)Sn的形态由粒状向片状转变。

In order to improve the oxidation resistance and wettability of Sn-0.3Ag-0.7Cu solder,P element was introduced into the solder alloy.The effect of P addition on the oxidation resistance,wettability and microstructure of Sn-0.3Ag-0.7Cu solder were investigated in detail.Firstly Sn-0.3Ag-0.7Cu-xP(x=0%,0.005%,0.010%,0.015%,0.020%,mass fraction)solder alloys with different P addition were prepared.The oxidation resistance and wettability of solder alloy were both tested.The microstructures of the solder alloy were characterized by both scanning electron microscope(SEM)and energy dispersive spectrometer(EDS).The results show that with the increasing of P content,the oxidation resistance and wettability of the solder can be improved obviously.Compared with 2.25 g of the solder without P,the oxidized slag is 0.79 g after 30 min dwelling at 250℃ in air when P content reached 0.020%.The spreading area and wetting force of the solder is 65.74 mm^(2) and 5.04 mN,respectively,the wetting time is 0.96 s.It is shown that the addition of P element does not change the phase composition.With the addition of P element,the microstructure of the solder is mainly composed of β-Sn,Ag_(3)Sn and Cu_(6)Sn_(5).With the increasing of P content,the morphology of Ag_(3)Sn changes from granular to sheet.