Wed, 11 Jul 2018 01:55:03 +0000
Necessary skills for using vacuum sintering furnace
Vacuum sintering furnace is mainly used for sintering technology of semiconductor components and power rectifier devices. It can be used for vacuum sintering, gas protection sintering and conventional sintering. It is a kind of novel technology equipment in the series of special equipment for semiconductor industry. It has a novel design idea, convenient operation and compact structure. It can also be used in vacuum heat treatment, vacuum brazing and other processes in other fields. What note does vacuum sintering furnace have to use?
I. necessary skills for the use of vacuum sintering furnace
Vacuum sintering furnace is after vacuum filling hydrogen protection condition, by using the principle of intermediate frequency induction heating, the high temperature of tungsten crucible in the winding, by heat conduction to work on, suitable for scientific research, military units for hard metal such as tungsten, molybdenum and its alloy powder sintering molding. The installation site of electric furnace should meet the requirements of vacuum hygiene, the surrounding air should be clean and dry, and good ventilation conditions, the working site is not easy to raise dust. Vacuum furnace
Daily use skills of vacuum sintering furnace:
1. Check whether all parts and accessories in the control cabinet are complete and intact.
2. The control cabinet is installed on the corresponding foundation and fixed.
3. Connect the external main circuit and control circuit according to the wiring diagram and refer to the electrical schematic diagram.
4. Check the movable part of the electric appliance, and it should be free from jamming.
5. The insulation resistance shall not be less than 2 megohm.
6. All valves of the vacuum furnace must be in the closed position.
7. Control the power switch in the off position.
8. Manual pressure adjusting knob counterclockwise rotating head.
9. Put the alarm button in the open position.
10, according to the plan complete equipment of circulating cooling water connection, recommend that users always in and out of the device ShuiGuanChu access another spare water (or water), to prevent the circulating water has a power failure or lead to seal burn out.
1, due to the mold, generally by the user should bring along their own, mold material selection basically high purity graphite, its pressure limit is 40 mpa, recommend that users use under 30 mpa safer, pressurized before should calculate the area of the upper and lower punch mould, and then converted to pressure, the specific formula is as follows:
The system allows pressure (ton) = top or bottom punch area * 30MPa
2. The thermocouple is tungsten-rhenium type, which will be brittle and untouchable after use. If damaged, it should be replaced in time. The model is the W2.
3. In winter, attention should be paid to the problem of keeping warm of circulating water, otherwise the water pipes will burst easily.
4. After use, the furnace body should be kept vacuum, because the heat preservation layer in the furnace is susceptible to moisture, and the vacuum should be maintained so that the vacuum can be pumped faster next time.
5. Due to the complexity of the equipment, it is recommended to use the equipment exclusively and exclusively, and strict pre-use training and post-use inspection for the novice should be carried out.
6. This hot-pressing furnace can also be used as a vacuum sintering furnace. When used in a vacuum sintering furnace, please note that after the crucible is placed in the furnace, don’t forget to cover the small cover between it after the cover of the heat preservation screen is put on. Otherwise it will burn out the electric furnace.
7, should be cleaned before operation observation window, clean the furnace wall, observe the water pressure, there is no damage to observe furnace graphite, electricity observation instrument display is normal, after testing the hydraulic system can work normally.
8. The meter should be sent to the metrology department for calibration after one year of use.
Emergency method of vacuum sintering furnace
Cooling water anomaly
1. Confirm that the heating power has stopped.
2, leaking, outside the furnace cooling water exception, should take emergency measures, as soon as possible if you can guarantee the water, please continue to keep the vacuum, such as not take emergency measures to keep the original state, confirm the equipment to cool down.
3. When the cooling water is abnormal, the equipment is in a stop state and the emergency cooling water is immediately connected.
4, in the high temperature (over 200 ℃ high temperature) shall be deemed to be, if the cooling water stop, if not an emergency water, water-cooled electrodes, heat exchanger, vacuum chamber and the pump shell may be damaged.
Stop compressed air
1. When abnormal alarm of compressed air occurs, the equipment is in a stopped state, and it should go to the spare compressor room as soon as possible to restore it to work.
2. In case of abnormal alarm of compressed air in vacuum, and the recovery takes a long time, the vacuum shall be terminated to stop the equipment.
All of a sudden power failure
1. In case of power failure, if the water is cut off, the spare cooling water shall be immediately connected to the water source.
2. If the equipment can be restored as soon as possible when it is not heated, heated and cooled, restart the equipment and keep running for a long time.
3. If the device is being heated and cooled, it can be restored as soon as possible, and restart the device. If it takes a long time, it will remain the same and allow the device to cool down naturally.
The heating power is off
1. The water is low, and when the water pressure is lower than 0.15mpa, the pressure gauge will alarm.
2. Ground fault.
3. Vacuum discharge. The connection between the water-cooled electrode joint and the heater must be firmly connected and well insulated from the reflection screen.
4. If the pressure in the furnace is 13.3-66.5Pa (this vacuum is easy to discharge). The reason of power failure can be regarded as the discharge caused by dielectric breakdown.
The aerated gas (argon or nitrogen) stops
1. Before the start of vacuum extraction, if the gas has been filled for a long time or cannot be filled, please confirm whether the gas pipeline is blocked.
2. If there is no problem with the gas pipeline, check the action of the solenoid valve and the gas charging valve. In order to ensure the safety of the equipment associated with it, the inspection shall be carried out after all the stops.
3. When the air filling into the vacuum chamber cannot be stopped, all gas systems including the gas supply valve and the distribution pipe shall be closed when the pressure relief valve ACTS as the pressure relief valve.
4. Confirm whether there is any air leakage in the gas filling pipe, if any, it will affect the product quality.
Vacuum chamber pressure deteriorates
1. When the vacuum exhaust time is longer than usual, the equipment should be stopped for inspection. According to the influence of different state of the vacuum indoor structure to lower the air, there are also cases of increased pressure.
2. Confirm the influence of air leakage and air release through pressure rise test or helium leak detection.
The above content is to introduce the necessary skills and the use of vacuum sintering furnace daily emergency method, in a vacuum and protective atmosphere, and for some metals, ceramics and refractory metal heating intermediate compound powder sintering, to obtain a certain density and has a certain mechanical properties of materials, generally USES two kinds of process; There is pressure sintering and no pressure sintering. Pressure sintering has the characteristics of high temperature, high vacuum and high thermal pressure