Vacuum metallurgical atmosphere sintering furnace
Principle, Characteristic and Function of Vacuum Atmosphere Sintering Furnace
Vacuum atmosphere box furnace is also called anaerobic annealing furnace and vacuum atmosphere sintering furnace. Widely used in ceramics, metallurgy, electronics, glass, chemical industry, machinery, refractories, new material development, special materials, building materials and other fields of production and experiment. Next, Xiaobian Xianji Network will take you to understand its principles, characteristics and functions!
Principle of vacuum atmosphere sintering furnace:
A method of sintering an object in a furnace into which a certain gas is injected. Choosing suitable atmosphere for sintering of different materials is helpful to sintering process, to improve the densification degree of products and to obtain products with good properties. Vacuum atmosphere furnace is commonly used in vacuum, hydrogen, oxygen, nitrogen and inert gas (such as argon) and other atmospheres. For example, transparent alumina ceramics can be sintered in hydrogen atmosphere, transparent ferroelectric ceramics should be sintered in oxygen atmosphere, and nitride ceramics such as aluminium nitride should be sintered in nitrogen atmosphere. In order to protect sintering coordination, it is sometimes necessary to operate in a protective atmosphere. If molybdenum wire furnace should be hydrogenated, tungsten wire furnace should work under vacuum conditions.
Characteristics of vacuum atmosphere sintering furnace:
1. Novel appearance, exquisite lathe processing, high temperature plastic-sprayed shell.
2. Furnace materials are all manufactured by imported Morgan (energy-saving effect is more than 60% of the old electric furnace).
3. Accuracy (temperature control accuracy: +1 C constant temperature (uniform) accuracy: +5 C;).
4. Thermal insulation performance (less than 30% of the total power in thermal insulation).
5. Microcomputer control, programmable, 50 section heating curve, automatic heating/cooling.
6. Working environment (anti-interference, shell temperature less than 30 C at 1400 C greatly improves the working environment).
7. Heating elements are distributed on both sides of the furnace.
8. Various kinds of gases can be added and vacuum pumped. The top and door of the furnace can be water-cooled.
9. Normal operating temperature of electric furnace: 0-1700 C.
10. Warming up (0-1400 C: 35 minutes; the fastest heating rate is 40 degrees/min, and different heating rates are different).
11. Vacuum 10-1 power Pa.
The function of vacuum atmosphere sintering furnace:
1. Reduce the harmful effects of harmful components (water, oxygen, nitrogen) in the atmosphere on the products. For example, it is quite difficult to reduce the dew point of water content in electrolytic hydrogen gas to 140 C, while the dew point of water content at 140 C is equivalent to that of vacuum at 133 Pa. It is not difficult to obtain such a vacuum.
2. Vacuum sintering can be used for materials which are not suitable to use reducing or inert gas as protective atmosphere (such as sintering of active metals), or which are prone to decarburization and carburization.
3. Vacuum can improve the wettability of liquid phase to solid phase, conducive to shrinkage and improve the structure of the alloy.
4. Vacuum sintering is helpful to remove impurities such as silicon, aluminium, magnesium and calcium or their oxides, and to purify materials.
5. Vacuum is conducive to the removal of adsorbed gases, residual gases in pore and products of reactive gases, and has a significant effect on promoting the shrinkage in the later stage of sintering. For example, the porosity of the vacuum sintered cemented carbide is much lower than that of the hydrogen sintered cemented carbide.
6. The temperature of vacuum sintering is lower than that of gas-shielded sintering. For example, the sintering temperature of cemented carbide can be reduced by 100-150 C. This is conducive to reducing energy consumption and preventing grain growth.