Surface Strengthening and Modification Technology of Die Casting Mold
Mon Jun 12 11:31:56 CST 2023
The surface strengthening and modification technology of the die-casting mold can design the mold surface and the substrate as a system as a whole, and comprehensively use the surface strengthening modification technology and coating technology to make the surface obtain materials that are difficult to possess and hope to have specific properties. The treatment technology that uses modern technology to change the material surface and subsurface layer composition, structure and performance of forging dies is called surface modification technology, which mainly includes the following ten categories:
1. Electrochemical conversion
The technology of forming an oxide film on the surface of parts in electrolyte solution and under the action of external current is called electrochemical modification technology. In engineering, the electrochemical conversion modification technology is often called anodic oxidation or anodization. So recently, a major development of electrochemical conversion technology is micro-arc plasma anodization, which can significantly improve the surface hardness or form a new color decorative film layer, and has a good application in the die-casting mold industry.
2. Surface formation transformation strengthening
Shot peening, extrusion, laser shock, rolling, ultrasonic shock, vibration shock, high-pressure jet and other processes are used to make the surface layer of the material produce elastic-plastic deformation, introduce residual compressive stress and produce changes in the microstructure, so as to improve the quality of the material. The ability of materials to resist fatigue and corrosion to improve the stability and durability of parts.
3. Surface transformation strengthening
Use electron beams, laser beams, etc. to rapidly heat the surface of the material to form new phase transition regions and surface strengthening amounts on the surface and subsurface, so as to obtain a special performance surface layer with fine structure and strengthening phase.
4. Ion implantation
The ions ionized by the vacuum system are accelerated under high voltage and directly injected into the surface of the die-casting mold material to form a thin ion implantation layer, which changes the composition and structure of the material surface and improves the surface properties of the material.
5. Organic and inorganic coating technology
Organic coating technology mainly refers to the use of coatings (paints, paints, pigments, thinners) to endow the surface of die-casting molds with special functions such as protection, decoration, flame retardancy, and temperature indication.
Inorganic coating technology is to form an inorganic covering layer or surface film on the surface of the mold. The inorganic covering layer or surface film has specific chemical composition, structure and morphology, which can endow the substrate and coating system with new properties or functions.
6. Surface alloying (diffusion infiltration)
Deposit metal or non-metal on the surface of the die-casting mold, penetrate into the surface of the base material through diffusion, change the chemical composition and phase structure of the material surface, and improve the performance of the mold surface.
7. Chemical transformation
Put the mold parts into a certain chemical solution medium to form a passive compound film on the surface to improve the performance of the mold surface. Passive compound films commonly used in engineering mainly include chromate passivation film, phosphate passivation film, oxalate passivation film, bluing on the surface of steel parts, etc. In addition, in engineering applications, surface roughness reduction processes (grinding, polishing, rolling, etc.) and surface coloring are often classified as surface modification processes such as chemical conversion.
8. Metal electrochemical deposition technology
Metal electrochemical deposition refers to the technology of depositing one or more layers of metal coating, alloy coating or composite coating on the surface of die casting mold by electrochemical method, also known as electroplating technology. A variety of coatings with different functions can be prepared on the surface of metal parts by electroplating.
9. Anti-rust technology
The chemical or electrochemical changes of metals under the action of environmental media are called metal corrosion, commonly known as rust or corrosion. Anti-rust metal is a technology to prevent metal from corroding during manufacturing, processing, handling, transportation, storage and use.
10. Hot dip coating technology
Hot-dip coating technology, also known as hot-dip coating, is a process technology in which the metal material to be plated is immersed in other liquid metals or alloys with a lower melting point to form a coating. The hot-dip coating technique is characterized by the formation of an alloy layer between the base metal and the coating metal.