Aluminum alloy die casting defect mending agent and preparation method thereof

Abstract

The invention provides an aluminum alloy die casting defect mending agent. The aluminum alloy die casting defect mending agent comprises a first component and a second component; the first component comprises polypropylene glycol diglycidyl ether, a fluorescent brighting agent, an antioxidant, silver coated copper powder and nonleafing aluminum powder; the second component comprises methylcyclohexanediamine, spirocyclic diamine, bisphenol A epoxy resin, liquid petroleum resin and a coupling agent; a mass ratio of the first component to the second component is (7-8):1; and the first component also comprises nano-silica modified bisphenol F epoxy resin and bisphenol A epoxy resin. The mending agent can be used for filling casting pores, shrinkage cavities, sand holes and cracks with different sizes, can work at -60-210 DEG C, has no color change or blackening phenomenon under high temperature conditions, has consistent color with a die casting aluminum alloy matrix, has high bonding strength with the matrix metal, does not shrink at a high temperature after being cured, and also has the advantages of high application property, good thixotropy, good acid, alkali and corrosion resistance, and good electricity and heat conduction performances.

Description

technical field [0001] The invention relates to a defect repairing agent for aluminum alloy die castings, in particular to a repairing agent for repairing defects of die castings of aluminum alloy communication equipment shells, and belongs to the technical field of chemical repairing agents. Background technique [0002] Aluminum alloy die castings will have defects such as pores, shrinkage cavities, sand holes, cracks, etc., which will affect the electromagnetic shielding performance and appearance of the communication equipment housing, resulting in the scrapping of the die casting housing and increasing the production cost. [0003] Manufacturers will take some repair measures to remedy casting defects. The main component of existing aluminum alloy die-casting defect repair agents on the market is amine-cured epoxy resin mixed with a small amount of flake aluminum powder, which can fill and repair pores and sand holes. Improve the appearance of the housing of communicati...

AI Technical Summary

Problems solved by technology

[0004] 1. It does not have a conductive function, but only has a certain appearance repair function. After repair, it will affect the electromagnetic shielding function of the communication equipment shell to a certain extent;

[0005] 2. The thermal conductivity is not good, the heat dissipation of the repaired communication equipment shell will be affected, and the key parts of the shell will have a temperature rise exceeding the allowable temperature when the equipment is working;

[0006] 3. The high temperature resistance is not good. Under high temperature conditions, the repaired position will turn yellow and shrink to varying degrees, and small pits will appear in the repaired position, which will affect the repaired appearance;

[0007] 4. Poor toughness, easy to crack due to cold and heat shock, resulting in cracks

[0008] The repair agent made of conductive silver powder or silver-coated copper powder and epoxy resin has good electrical and thermal conductivity, but its appearance is not good, especially under high temperature conditions, silver is oxidized, and the color is yellowish and dark, and The appearance and color of die-casting aluminum substrates are quite different, and there are also problems of high temperature shrinkage and poor toughness, and the repair effect is not good.