A surface protection method for highly active porous materials

Abstract

The invention provides a surface protection method for a high-activity porous material. The surface protection method comprises the following steps that (1) the high-activity porous material is subjected to pretreatment so that wax, oil or / and rust on the surface of the high-activity porous material can be removed; (2) the high-activity porous material is immersed into a cyanide-free electro-coppering solution through a electrified trough entering mode, ultrasonic waves are supplied at the same time, or the cyanide-free electro-coppering solution is circulated through a high-pressure pump and used for washing out a matrix in a high-pressure micro-jet mode, and thus, the high-activity porous material instantly impacts pre-plated copper at the large current density value in the cyanide-free electro-coppering solution; and (3) the high-activity porous material is not subjected to water treatment, continues to be plated with a copper plating layer which is 1-15 [mu]m thick in the cyanide-free electro-coppering solution and finally continues to be plated with a single or combined electro-plating layer of nickel or zinc or copper or chromium. According to the surface protection method provided by the invention, displacement of the electro-plating solution and a matrix material can be effectively avoided, the wettability to the matrix is good, air cavities are prevented from being formed in pores, blind holes are quickly filled with the electro-plating solution, and meanwhile, high-speed deposition of the copper plating layer is instantly achieved.

Description

technical field [0001] The invention belongs to the technical field of material surface protection, and in particular relates to a surface protection method for highly active porous materials. Background technique [0002] Highly active porous materials refer to bulk materials with high chemical activity, which are formed by powder pressing and sintering or melt die-casting. There are many tiny pores inside the bulk material when observed under a high-power microscope. Representative materials include sintered NdFeB permanent magnet materials, zinc alloy or magnesium alloy die-casting materials, etc. Zinc alloy die casting material, in terms of composition, it is mainly composed of 95wt% zinc, 4wt% aluminum and a small amount of copper, magnesium and other metals, so the electrode potential is relatively negative. When the die-casting is solidified, the surface will segregate to form an aluminum-rich phase and a zinc-rich phase. Regardless of strong alkali medium or strong ...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem of highly active porous materials in the traditional electroplating process, the substrate is easily corroded by the plating solution, and the metal cannot be plated in the tiny pores, resulting in poor bonding of the coating, and even corrosion from the inside out (the coating is intact, but The substrate inside the coating has been rusted or pulverized), the invention provides a surface protection method for highly active porous materials, which can effectively avoid the displacement of the electroplating solution and the substrate material, and has good wettability to the substrate, preventing Air cavities are formed in the pores, and the plating solution quickly fills the blind holes, and at the same time realizes the high-speed deposition of copper plating in an instant