Release time：2022-06-27 17:34 click：1
The promotion of 5G network construction will become a key work in 2020. With the gradual implementation of 5G base stations around the world, the high demand for 5G communication base stations and filters has driven a new wave of demand for precision metal structural parts industry chain. For example, the mobile phone die-casting medium plate driven by the popularity of 5G mobile phones has brought a new wave of growth point to metal processing manufacturers. 5G base station structure, heat dissipation shell, filter cavity, antenna, aluminum alloy structure and filter of communication equipment, especially filter cavity and base station heat dissipation shell of semi-solid die-casting parts.
Now let's take a look at the semi-solid processing technology; This paper comes from the theory and technology of semi-solid processing of metal materials.
One: the basic introduction of semi-solid processing
Semi-solid processing is the use of metal from liquid to solid transformation or from solid to liquid transformation (i.e., liquid and solid coexistence) in the process of the characteristics of the forming method, semi-solid processing of the basic process according to the state of the material into the mold cavity is divided into thixoforming and rheological forming two.
Two: semi-solid rheological slurry preparation
Will design the ratio of good raw materials such as magnesium, aluminum alloy after heating, melting, through severe mechanical agitation or electromagnetic stirring, fully broken dendritic primary solid phase, is a kind of liquid metal in the mother liquor evenly suspended some globular primary solid phase of solid-liquid mixed slurry (solid phase components generally around 50%), namely the rheological slurry.
This semi-solid slurry viscosity is higher than liquid metal, easy to control, can be formed at a higher speed, easy to achieve automatic production, improve production efficiency. For some products with large volume, high precision and complex structure in 5G communication equipment, it is more conducive to realize automatic processing.
Three: semi-solid forming processing type
1. Rheological forming (one-step method)
The semi-solid slurry prepared by heating, melting and stirring is directly pressed into the mold cavity by die-casting machine or extruder. This method is called rheoforming of semi-solid metal, also known as one-step method.
2. Thixotropy (two-step)
The semi-solid slurry prepared into billet, after secondary heating to semi-solid temperature, and then through the die casting machine or extruder pressed into the mold cavity forming processing, namely thixoforming, also known as the two-step process.
5G communication equipment has higher requirements for metal structural parts. The advantages of semi-solid die-casting are mainly reflected in high strength and ultra-thin. Excellent heat dissipation effect; At present, the thickness of the heat dissipation teeth of the heat dissipation shell of 5G base station can reach less than 1.2mm, and the thinnest one even has 0.9mm.
