Application of graphite abrasives

At present, graphite molds have been widely used in the following aspects:

Graphite mold for continuous and semi-continuous casting of non-ferrous metals

In recent years, advanced production methods such as direct continuous (or semi-continuous) manufacturing of rods or pipes from the molten metal state are being promoted at Home and abroad. Domestic in copper, copper alloy, aluminum, aluminum alloy and other aspects have begun to use this method. Artificial graphite is considered to be the most suitable material for continuous casting or semi-continuous casting of non-ferrous metals. Production practice has proved that due to the use of graphite mold, due to its good thermal conductivity (thermal conductivity determines the solidification rate of metal or alloy), the self-lubrication performance of the mold is good and other factors, not only the casting speed is improved, but also because the size of the ingot is accurate, the surface is smooth, and the crystallization structure is uniform, it can be directly processed in the next process. This not only greatly improves the finished product rate, reduces the waste loss, and the product quality has also been greatly improved. There are two continuous casting methods: vertical continuous casting method and horizontal continuous casting method.

Die for pressure casting

Artificial graphite materials have been successfully used in pressure casting of non-ferrous metals. For example, zinc alloy and copper alloy castings produced by pressure casting molds made of artificial graphite materials have been used in automotive parts and so on.

Graphite mold for centrifugal casting

Graphite mold has been successfully applied in centrifugal casting. The United States has used artificial graphite casting mold with wall thickness of more than 25 mm to centrifugally cast bronze casing. In order to prevent the burning of artificial graphite mold, certain anti-oxidation measures can be taken. After casting a certain number of castings, if the inner surface of the mold is found to be burned, the size of the hole in the mold can be enlarged for casting large casing.

Hot pressing die die

Artificial graphite hot pressing die for the pressurization of cemented carbide has the following characteristics: first, if the pressing temperature is increased to 1350-1450 degrees, the required unit pressure can be reduced to 67-100 kg force/square centimeter (that is, 1/10 of the cold pressing pressure); Second, pressure and heating are carried out in the same process, and dense sintered bodies can be obtained after a short time of sintering.

Molds for glass forming

Because the graphite material has chemical stability, is not easy to be infiltrated by molten glass, will not change the composition of the glass, the graphite material has good thermal shock performance, the size changes with the temperature, etc., so in recent years, it has become an indispensable mold material in glass manufacturing, and it can be used to make glass tubes, bending tubes, funnel and other kinds of shaped glass bottles.

Sintering dies and other diamond sintering dies

Using the characteristics of artificial graphite material with minimal thermal deformation, the sintering mold and bracket of transistors can be manufactured, and it has been widely used, and it has become an indispensable material for the development of semiconductor industry. In addition, graphite molds are also used in cast iron molds, durable molds for various non-ferrous metals, cast steel molds, heat-resistant metal (titanium, zirconium, molybdenum, etc.) molds and thermite welding molds for welding rails. The graphite mold used for hot-pressing sintered diamond tools plays the dual role of heating element and mold support in the manufacturing process of diamond tools. The quality of graphite molds directly affects the dimensional accuracy and appearance of diamond tools. Hot press sintering process requirements: the temperature reaches (1 000±2)℃, the forming pressure is 16~50 MPa, the heat preservation and pressure holding time is 15~30 min, and the environment is non-vacuum. Under this working condition, it is required that the graphite mold of the molding and heating elements have electrical conductivity, high resistivity and sufficient mechanical strength, and it also needs to have good oxidation resistance and long service life to ensure the dimensional accuracy and excellent performance of diamond tools. At present, graphite mold materials for diamond tool manufacturing in Western developed countries are mainly ultrafine particle structure, high purity and high graphitization graphite materials, requiring its average particle size to be less than 15μm, or even less than 10μm, and medium porosity size to be less than 2μm. The graphite mold made of this carbon raw material has small porosity, dense structure, high surface finish, strong oxidation resistance, and an average service life of 30~40 times. Diamond mold requires high material hardness, good oxidation resistance, high processing precision, the use of high-quality graphite raw materials greatly extend the service life of the mold and improve the oxidation resistance.

Processing technology

First of all, it is designed by the mold designer according to the requirements of the use of Products (parts), the mold structure is designed, and the drawings are drawn by the technical workers according to the requirements of the drawings through a variety of mechanical processing (such as lathes, planers, milling machines, grinding machines, electric discharge, wire cutting and other equipment) to do each part on the mold, and then assembled and debugging until it can produce qualified products.

Current situation and development

Today, the graphite mold industry plays a vital role in human life and development, many industrial sectors (such as mechanical and electrical, automotive, home appliances, light industry, electrical instrumentation, communications, ordnance, etc.) development depends on the mold industry technology improvement and development, all countries in the world have invested a lot of human and financial development of graphite mold industry. Like Germany's SGL and Japan's Toyo Carbon have achieved a leading position in the international graphite mold industry. China also attaches great importance to the development of the mold industry, and the level of mold production technology has become an important symbol to measure the level of product manufacturing in a country, because the mold largely determines the quality, efficiency and development ability of new products. Since 1997, the relevant departments of our country began to pay attention to and support the development of graphite mold industry, and vigorously support the development of Chinese local enterprises in the graphite mold industry, and now has achieved good results and contributed to China's export foreign exchange earnings. For the development trend of the mold industry in the future, who can complete the production of molds in the shortest time, who will win customers and win the market. Graphite mold (graphite electrode) with its superior performance in all aspects, has established an important leading position in the mold industry and the future development trend.