Introduction of Vacuum Hot Pressing Furnace Performance

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The vacuum hot pressing furnace is a vertical vacuum resistance furnace that uses graphite as a heating element, with a frame-type double-pillar support outside. There is a hydraulic cylinder lifted and lowered as a pressure source for metal compounds, ceramics, inorganic compounds, nano materials, etc. to heat and press products in a vacuum or protective atmosphere. It is widely used in cemented carbide, functional ceramics, powder metallurgy, etc. for hot pressing and sintering under high temperature and high vacuum conditions. It can also be hot pressed and sintered under inflatable protection.

Components of vacuum hot pressing furnace:

1.  Vacuum system: It is composed of oil diffusion pump, Roots pump, mechanical pump with electromagnetic differential pressure valve, inflation valve, bleed valve, vacuum butterfly valve, vacuum pressure gauge, bellows, vacuum pipeline and bracket.

2. Hydraulic system: Electric input mode is adopted. The hydraulic station is equipped with imported proportional valves, pressure sensors, displacement indicators, grating rulers, hydraulic cylinders and other related hydraulic devices. The pressure adjustment is semi-automatic and can be adjusted manually. The instrument can be set to automatically adjust the pressure, and can achieve stable pressure.

3. Water cooling system: It is composed of various valve and pipeline related devices and is equipped with water-breaking sound and light alarm to automatically cut off the heating source or function.

4. Temperature control system: SCR temperature control, equipped with PID function instrument, digital display meter, with The over-temperature sound and light alarm function can also be automatically controlled by the PIC touch screen, and historical data is retained for easy analysis of the sintering process. \

5. Inflation system: It is composed of various pipes and valves, and is equipped with electromagnetic deflation valve and pressure sensor. When the pressure in the furnace is higher than the safe value, it will automatically deflate. There is a needle valve on the inflation pipeline to control the amount of inflation.

Precautions for the use of vacuum hot pressing furnace:

Since the mold is generally prepared by the user, the heating material is basically high-purity graphite, and its pressure limit is 40MPa. It is recommended that the user use it under 30MPa, which is safer. The upper and lower molds should be calculated before pressurization. The accumulation of the punch is then converted into pressure. If the blind day pressure is not calculated in advance, it will cause damage to graphite products such as molds, briquettes, heating elements, and thermal insulation screens. Manually raise the temperature when the furnace temperature is below 200C, otherwise the temperature control will be inaccurate. Press the heating and start button in the vacuum state, and slowly adjust the “manual power adjustment” to make the current rise slowly, and it is forbidden to exceed the rated current of 1200A. The surface of the vacuum furnace should always be kept clean and tidy, and the vacuum should be kept when not in use, otherwise the vacuuming efficiency will be reduced when it is used next time. The vacuum furnace and vacuum system should be filled with vacuum sealing grease for about half a year. The axial sealing refers to the observation window baffle seat, pneumatic vacuum butterfly valve and other parts.

Advantages of vacuum hot pressing furnace:

1. Greatly reduce the forming pressure, the pressure used during hot pressing is only about 1/10 of that of cold pressing, so hot pressing can press large products.

2. The effect of powder size and hardness on the hot pressing process is not obvious, so hot pressing can compress some hard and brittle powders.

3. The powder has good plasticity during hot pressing and can be pressed into special-shaped products such as flakes and thin-walled tubes.

4. Shorten the sintering time