What are the characteristics of tungsten and tungsten alloy sintering furnaces
source:
www.361jb.com | publish time:2025年10月11日
The tungsten and tungsten alloy sintering furnace is a core equipment specifically used for densification of tungsten powder and tungsten alloy billets (such as tungsten electrodes, tungsten targets, and hard alloys) through high-temperature sintering. Its characteristics revolve around "high temperature resistance, correct temperature control, controllable atmosphere, and adaptation to tungsten material properties", as follows:
1. Ultra high temperature heating capacity
Tungsten and tungsten alloys have a high melting point (pure tungsten melting point 3422 ℃), and the sintering furnace needs to have a stable heating range of 1800-2400 ℃. The mainstream uses graphite heating elements and tungsten wire/tungsten mesh heating elements (high temperature resistance and good compatibility with tungsten materials), which can meet the sintering needs of different tungsten products (such as tungsten billet densification requiring over 2000 ℃, and tungsten alloy composite sintering requiring 1800-2200 ℃).
2. Correct temperature control
The sintering process requires strict temperature uniformity (excessive temperature difference can cause deformation and uneven density of the billet), and the equipment is usually equipped with multiple sets of thermocouples for temperature measurement and PID intelligent temperature control system. The temperature difference in the effective heating zone inside the furnace can be controlled within ± 5 ℃; Some models support segmented temperature control to meet the multi-stage process requirements of "heating insulation cooling" during sintering.
3. Strict atmosphere control
Tungsten is prone to react with oxygen and nitrogen at high temperatures to form compounds (affecting purity and performance), so sintering furnaces need to have vacuum or inert gas protection functions:
Vacuum atmosphere: The air inside the furnace is removed through a high vacuum system (with a vacuum degree of up to 10 ?3 -10 ?? Pa) to avoid tungsten oxidation, making it suitable for sintering high-purity tungsten products (such as tungsten wires and tungsten targets);
Inert gas atmosphere: Introduce argon and hydrogen (reducing gases that can remove trace oxide layers on the surface of the billet), suitable for sintering tungsten alloys (such as tungsten copper and tungsten nickel iron), to prevent oxidation of alloy elements.
4. Structural design adapted to tungsten materials
Furnace cavity material: using high-density graphite crucible, tungsten crucible or alumina ceramic lining, high temperature resistance and no reaction with tungsten billet;
Bearing device: Use graphite trays and tungsten alloy brackets to carry the billet, avoiding deformation or contamination at high temperatures;
Slow cooling system: Tungsten and tungsten alloys have low thermal expansion coefficients but high brittleness. The furnace is equipped with a slow cooling device (such as programmed cooling) to prevent rapid cooling from causing cracking of the billet.
5. High stability and safety
Heating system: using high-temperature resistant insulation materials (such as alumina ceramics) to isolate the heating element from the furnace body, preventing leakage or overheating;
Pressure/Vacuum Monitoring: Real time monitoring of furnace pressure and vacuum level, automatic alarm and power cut-off in case of abnormalities;
Durability: The core components (heating element, thermocouple, vacuum valve) are made of wear-resistant materials with a long service life, suitable for the "batch and long-term" sintering requirements of tungsten products (single sintering cycle often reaches 10-24 hours).