Laser Guided Nano-Brazing Method for Reinforced Aluminum Composite Material having High Volume Fraction Silicon Carbide Particles

摘要

A laser guided nano-brazing method for a reinforced aluminum composite material having high volume fraction silicon carbide particles, comprising 4 steps: nanocrystallizing the surface of the reinforced aluminum composite material having high volume fraction silicon carbide particles, preparing solder material, assembling pieces to be soldered, and dual-beam laser brazing. The use of nano-technology for the brazing of reinforced aluminum composite material having high volume fraction silicon carbide particles, and the use of dual-beam laser technology for brazing temperature field control enhance the humidity during the brazing process of said material and filling ability of the solder material, and satisfy the strict requirements of electronic packaging.

主权项

1. A laser-induced nano-brazing method for reinforced aluminum matrix composite with high volume fraction of silicon carbide particulates, characterized in that, said laser-induced nano-brazing method for reinforced aluminum matrix composite with high volume fraction of silicon carbide particulates comprises the steps of:
(1) carrying out nanocrystallization for a brazing surface of a substrate of reinforced aluminum matrix composite with high volume fraction of silicon carbide particulates through which a nanocrystalline layer on the brazing surface of an upper substrate and a nanocrystalline layer on the brazing surface of a lower substrate are formed, wherein the upper substrate and the lower substrate are reinforced aluminum matrix composite with high volume fraction of silicon carbide particulates; (2) preparing a brazing filler in which the brazing filler is a silver-based brazing filler, an aluminum-based brazing filler or a zinc-based brazing filler, wherein the silver-based brazing filler comprises 40˜50 parts of Ag, 20˜25 parts of Cu, 9˜12 parts of In, 16˜20 parts of Sn and 2˜5 parts of Mg by weight; wherein the aluminum-based brazing filler comprises 20˜25 parts of Cu, 3˜8 parts of Si, 1˜3 parts of Mg 0.5˜2 parts of Ni and 65˜80 parts of Al by weight; wherein the zinc-based brazing filler comprises 55˜60 parts of Zn, 12˜18 parts of Cd, 10˜15 parts of Ag and 13˜18 parts of Cu by weight; (3) assembling an object for brazing in which the brazing filler prepared by the step (2) is placed between the brazing surface of the upper substrate and the brazing surface of the lower substrate prepared by the step (1) to form the object for brazing; (4) carrying out dual beam laser brazing of which under protection of argon atmosphere, converging the focus of two laser beams onto the object for brazing at a position which is 1˜2 mm below a surface of the object for brazing, wherein a beam diameter of the laser beam is 0.5˜1.5 mm and a distance between the beam center of the two laser beams is 2˜5 mm; welding by the two laser beams simultaneously in which the welding speed is 15 mm/s˜20 mms, wherein a power density of the laser beam at a front side is 102 w/cm2˜104 w/cm2 and a power density of the laser beam at a rear side is 105 w/cm2˜107 w/cm2, thereby achieving the laser-induced nano-brazing method for reinforced aluminum matrix composite with high volume fraction of silicon carbide particulates.