The invention relates to a novel nano metal solder and a preparation method thereof, and belongs to the field of welding materials. The invention utilizes the nano metal micropowder produced by the physical vapor phase method to prepare a novel solder, which can be composed of one or more metal nano-powders, and the metal nano-powder consists of a main additive component and an auxiliary component, wherein the main addition The component is one of nickel or copper or a combination thereof, and the relative content is 65-100 wt%; the auxiliary component is a combination of one or more metals of aluminum, iron, zinc, titanium, chromium, silicon, The relative content is 0-35 wt%. This solder has the characteristics of low soldering temperature, low solder usage (low cost), simple process and high soldering strength.
Welding technology features
Due to the small particle size, large specific surface area and high surface activity, nanomaterials have significantly lower melting point and sintering temperature than conventional materials, hardness and fracture strength, and enhanced atomic diffusion. Using the nano-powder prepared by the company's electric explosion method, we have developed a new generation of high-performance paste, wire, soldering iron and other products. The time results show that this new welding material has the following characteristics:
1. Low welding temperature: nano metal powder, especially nano metal powder prepared by electric explosion method. The surface of the particle contains high surface energy. During the heating process, part of the surface energy will be released, so that the solder and the weldment can be Reliable soldering at lower temperatures;
2. High welding strength: Due to the small particle size of the nanoparticles, the bonding between the solder and the weldment is tighter, and the interfacial bonding strength of the solder layer and the weldment can be improved. Meanwhile, the small size of the metal nanopowder will make the solder layer structure. Refining reduces the critical dimension of the defect, so that the hardness and fracture strength of the solder layer and the bonding strength between the solder layer and the weldment interface are improved. In addition, the small particle size of the metal nanoparticles greatly increases the interface concentration of the solder layer. , which contributes to the atomic diffusion between the weldment and the solder layer, and also improves the welding strength;
3. Small welding deformation: the metal nano-fine powder particles are fine. Compared with the micro-particles, the thermal stress generated during the welding process can be mostly eliminated by metal grain slip or grain plasticity. After welding, the weldment generally does not need to be annealed. Destressing
4. Simple operation process: This solder is still used in a vacuum or inert protective atmosphere using conventional welding equipment. When solder paste is used, the weldment does not need to be pre-positioned and has self-supporting ability.
This technology is mainly suitable for brazing and pressure welding of metal materials, especially spot welding, and is especially suitable for welding of mechanical parts with complex and small deformation. At present, the project has applied for a national patent, and the patent application number is 01127105.
PFALL , https://www.pfallfurniture.com