The shell of a notebook computer is the most important part to protect the body. At the same time, its material affects its heat dissipation effect and weight; and it will directly bring people a visual experience.
There are two main types of materials used in notebook computer cases; one is an alloy case, and the other is a plastic case.
Alloy casings include: aluminum-magnesium alloy, titanium alloy and magnesium-aluminum alloy; plastic casings include: carbon fiber, PC-GF-## (polycarbonate PC) and ABS engineering plastics.
Al-Mg alloy: Al-Mg alloy is an alloy with aluminum as a matrix and a small amount of magnesium and other alloying elements. It is generally called aluminum alloy. It has the general characteristics of metal materials; it has good heat dissipation and strong pressure resistance, which can fully meet the requirements of 3C products with high integration, thinness, miniaturization, anti-dropping, electromagnetic shielding and heat dissipation. Its hardness is much more than that of a traditional plastic case, and its weight is only one-third of the latter. It is usually used for the shell of notebooks with medium or high-end ultra-thin or small size. Moreover, it can also be colored by surface treatment, which is favored by young people who are pursuing fashion. However, due to the high cost, notebook computers generally only use aluminum alloy on the top cover.
Titanium alloy: The strength and surface texture of the titanium alloy material are better than those of the aluminum-magnesium alloy material, and the processing performance is better, the pressure it can withstand is also larger, and it can support large-sized displays. Therefore, even if the titanium model is equipped with a 15-inch display, it is not necessary to reserve a too wide frame around the panel. The disadvantage of titanium alloys is that complex processing procedures such as welding can be used to make complex notebook computer casings. These production processes generate considerable costs and are therefore very expensive.
Magnesium-aluminum alloy: Magnesium-aluminum alloy is an alloy with a small amount of aluminum and other alloying elements as a matrix, and is generally called a magnesium alloy. People often confuse her with aluminum alloy. In fact, these are two completely different alloys. Compared with aluminum alloy, magnesium alloy has better heat dissipation, better crash resistance, and electromagnetic shielding. And it is one quarter to one third lighter than aluminum alloy, and is usually used for high-end ultra-thin or smaller notebook shells. However, at present, due to the higher material cost and surface treatment cost, and the molding is more difficult than the former (requires the use of stamping or die-casting processes), there are not many cases using magnesium alloys to manufacture the chassis. With the improvement of surface treatment technology, the use of this material is very promising.
Magnesium alloy notebook case application needs to break through the bottleneck
As mentioned earlier, people often confuse magnesium alloy with aluminum alloy. In fact, most metal notebooks on the market are made of aluminum alloy. The magnesium alloy notebook case is only used by a small number of foreign manufacturers for small and medium-sized notebooks. The magnesium alloy shell is divided into two types according to the molding method. One is plastic processing, that is, the magnesium alloy sheet is formed by stamping and the other is pressure casting. The notebook casings of magnesium alloys that we usually see are usually the latter.
For the former, due to the difficulty of plastic deformation of magnesium alloys and the high cost; manufacturers generally do not want to use them, but because the magnesium alloy notebook shells formed by plastic processing have better strength and toughness, stamped and formed magnesium Alloy notebook shells are still used by notebook manufacturers in small quantities, and are currently only used for high-end ultra-thin and smaller notebook shells.
At present, the research and development and application of magnesium alloy computer notebook shells have been carried out earlier, and the leading country in application is Japan. Judging from the situation in Japan; as early as 1997, the use of die-cast magnesium alloys on the thinnest computer notebooks at that time began, but it was not until 2003 that the use of rolled magnesium alloy sheets for stamping and forming computer notebook shells began, with an interval of 6 years For a long time, it can be seen that the stamping-formed magnesium alloy notebook shell with better strength and toughness, the processing technical difficulty is quite high.
In terms of die-cast magnesium alloy computer notebook shells, China can already be produced in batches. However, in terms of stamping and forming computer notebook shells with magnesium alloy sheets, industrial scale production technology has not yet been obtained.
There are two reasons for this, and it can be said that they are two technical difficulties. First, the magnesium alloy sheet with good plastic workability that can be used for stamping and forming has not reached the level of industrialized production in China; secondly, the stamping technology of magnesium alloy sheet itself has not reached the level of industrialized production.
First of all, there is the problem of sheet metal. There are many methods for manufacturing magnesium alloy sheet materials in the research and development stage, such as continuous casting and rolling, multi-pass warm rolling, extrusion slab + finishing rolling, etc. Among the latter two forms of magnesium sheet, the stamping performance is relatively better. In particular, the magnesium alloy sheet is manufactured by the method of extrusion and slab rolling + finishing rolling, which can reduce the number of rough rolling hot rolling passes, thereby greatly reducing the processing cost, and through the final finishing rolling, the magnesium sheet can meet the requirements of stamping processing. Of plasticity. This is a very promising process route for processing magnesium alloy sheet. The disadvantage is that the width is limited, generally in the range of 100 ~ 600mm; but it is sufficient for the shell of 3C electronic products such as computer notebooks.
Due to the characteristics of magnesium alloys, stamping and forming of magnesium alloy sheets is quite difficult. Often, the joint efforts of multiple upstream and downstream processes are required to achieve the perfect forming of the final product. Currently, only a few manufacturers have mastered practical technology, and this technology is still Perfecting.
The realization of large-scale stamping production of magnesium alloy sheet at room temperature is a necessary condition for the large-scale use of magnesium alloy sheet in the 3C industry. In order to achieve this goal, the industry still has a lot of work to do, such as developing new alloy varieties, new casting technology, extrusion technology, rolling technology and stamping technology.