Wed, 25 Jul 2018 01:54:59 +0000
Powder metallurgy vacuum sintering furnace
Aiming at the characteristics of time degeneration, large hysteresis and non-linearity of vacuum sintering furnace in powder metallurgy, the fuzzy control algorithm is adopted, and the PID control effect is not ideal. PID control and fuzzy control simulation model is established, were compared, the results show that the fuzzy control, the system response speed, steady-state time of just 3.2 s, there is no overshoot, steady-state error is 1.2 ℃, the steady-state accuracy is high; The simulation output of the system is close to the given input waveform, and the system has a short time of adjustment, which soon enters a stable state, and the oscillation is very small. The fuzzy control is superior to the traditional PID control and can meet the control requirements of the vacuum sintering furnace temperature of powder metallurgy.
The vacuum sintering furnace of powder metallurgy is a time – varying, hysteresis and nonlinear heating system. When the parameters change greatly and the control precision is high, the general PID control effect is difficult to be satisfied. Fuzzy control does not require the system to provide accurate mathematical models. According to people’s practical experience, control rules are formulated and control decision tables are made. The system is controlled according to decision tables, especially suitable for complex industrial production objects such as sintering furnace. Sintering process is the main factor affecting the quality of products sintering temperature and sintering time, particularly is a tall to the requirement of temperature, temperature difference between general does not allow more than a given value of plus or minus 3 ℃ ~ 5 ℃, so must be strictly controlled.
Description of vacuum sintering furnace
Vacuum sintering furnace is a kind of furnace in which the heated articles are sintered in a vacuum environment.
Vacuum sintering furnace is one of the most advanced temperature measurement, temperature control technology, intelligence, new material technology and furnace design technology for our engineering technicians. It is a kind of intermittent high vacuum furnace. According to the needs of sintering process time, it can configure multiple electric furnaces with a single set of power supply, which can realize continuous work by heating up the electricity and cooling off the power of a single furnace respectively.
USES of vacuum sintering furnace:
It is used for vacuum sintering of hard alloy, copper tungsten alloy, tungsten, molybdenum, aluminum nickel cobalt permanent magnet, SmCo5, Sm2Co17, ndfeb, titanium alloy and other alloy materials and ceramics.
Characteristics of vacuum sintering furnace:
Ultra high temperature furnace within 2400 ℃, it can fully meet all kinds of material sintering.
Using digital display intelligent temperature control system, the temperature control process can be completed automatically and accurately. The system can heat up according to the given temperature rise curve, and can store 20 different process heating curves in 400 sections.
Adopt internal circulation pure water cooling system, digital flow monitoring system;
High performance medium frequency contactor is used to convert furnace body automatically.
Comprehensive PLC water, electricity and vacuum automatic control and protection system.
Main technical parameters:
The highest temperature: 1600 ℃, 2000 ℃, 2400 ℃
High temperature area volume: 0.01m3, 0.02m3, 0.03m3, 0.05m3, 0.1m3, 0.15m3, 0.2m3, 0.3m3
Working atmosphere in furnace: vacuum
Temperature uniformity: plus or minus 10 ℃ or less
Temperature measurement: far infrared optical temperature measurement, temperature measuring range, or 0 ~ 2400 ℃; Temperature measurement accuracy: 0.2-0.75%.
Temperature control: program control and manual control; Temperature control precision: + / – 1 ℃
Limit: temperature 200 ℃ / min (empty furnace, depending on high volume and furnace structure))