Low-melting-point In-Bi-Sn-Ag alloy brazing filler metal and preparation method and application thereof

• Main Authors: GU YIBING, REN JING, HUANG MINGLIANG, HUANG FEIFEI, YANG HAOQI, LAN JIANI
• Format: Patent
• Language: Chinese; English
• Published: 09.04.2024
• Subjects: ALLOYS; CHEMISTRY; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; FERROUS OR NON-FERROUS ALLOYS; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; PERFORMING OPERATIONS; SOLDERING OR UNSOLDERING; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WELDING; WORKING BY LASER BEAM

The invention discloses low-melting-point In-Bi-Sn-Ag alloy brazing filler metal as well as a preparation method and application thereof. The In-Bi-Sn-Ag alloy brazing filler metal comprises the following components in percentage by mass: 15%-25% of Sn, 10%-30% of In, 1%-12% of Ag and 40%-60% of Bi. The ratio of the sum of the atomic percent of In and Ag to the atomic percent of Bi and Sn is 35.7: 39.3: 25. Based on a (cluster) connecting atom theoretical model, in combination with a phase diagram, mixing enthalpy and a strong interaction principle, combined with compound addition of an Ag element and an In element on the basis of Sn-Bi, and strict control of the composition proportion of all alloy elements, the low-melting-point lead-free solder has the advantages of being low in melting point, good in wettability of Cu and Ni substrates, high in welding strength, moderate in cost, free of lead, more environmentally friendly and the like, and has a wide application prospect. The method is especially suitable