Low vacuum atmosphere furnace, application of new material sintering, annealing, and reduction heat treatment

　　Low vacuum atmosphere furnace is a heat treatment equipment that integrates low vacuum pumping, controllable atmosphere, and high-temperature heating. When working, the air inside the furnace is first extracted by a mechanical pump to reduce the oxygen content, and then inert gases such as nitrogen and argon are introduced. A small amount of reducing gas can also be introduced to achieve a negative pressure atmosphere environment. Compared with high vacuum furnaces, the equipment structure is simple, the investment cost is lower, and the vacuum pumping time is shorter. It is more suitable for new material research and development, small-scale pilot testing, and the completion of the three core heat treatment processes of sintering, annealing, and reduction. It is widely used in university laboratories, new material enterprises, and powder metallurgy workshops.

A commonly used experimental small high temperature box atmosphere furnace (click on the image to view product details)

1. Introduction to the Three Core Heat Treatment Processes (1). New material sintering process Common processes for low vacuum atmosphere furnaces. Place ceramic powder and metal powder blanks into the furnace, evacuate the interior of the blanks to remove adsorbed water vapor and air, and then introduce a protective atmosphere for high-temperature insulation sintering. In a low oxygen sealed environment, it effectively avoids high-temperature oxidation and surface peeling of the green body, promotes the fusion and densification of powder particles, reduces the porosity of sintered parts, and improves material strength and density. Applicable materials: structural ceramics such as alumina, zirconia, and silicon nitride; Lithium battery powder, magnetic powder, metal composite powder, hard alloy body, etc. (2). Annealing heat treatment process Annealing is used to eliminate internal stress in materials, optimize crystal structure, and improve toughness and magnetic properties. Slowly raise the temperature and keep it warm in a low vacuum and protective atmosphere environment, and then control the temperature drop along with the furnace to prevent oxidation during the cooling process. Common scenarios: Stress relief annealing of metal alloys, crystallization annealing of magnetic materials, stress release after ceramic sintering, and annealing of thin film substrates to repair lattice defects. It can effectively reduce workpiece deformation and stabilize material physical and chemical properties. (3). Reduction heat treatment process For metal oxide powders, hydrogen gas or a mixed reducing atmosphere is introduced in a low vacuum environment to reduce the metal oxide into high-purity metal powder. Low vacuum can quickly remove the water vapor generated by the reaction, improve reduction efficiency, and reduce impurity content. Commonly used for: reduction of oxides such as iron oxide, tungsten oxide, molybdenum oxide, etc. to prepare high-purity metal powder; Catalyst precursor reduction activation. >Attention: When using hydrogen reduction, the equipment needs to be equipped with explosion-proof and exhaust gas treatment safety components. 2. Applicable materials and industry application fields (1). new energy materials Lithium battery positive/negative electrode powder, solid electrolyte material, magnetic powder. Low vacuum atmosphere protection for calcination, sintering, annealing, isolating air, and ensuring powder purity is a commonly used equipment in the research and development of new materials laboratories. (2). Advanced Ceramic Industry Pre firing and sintering of alumina, zirconia, silicon nitride, and silicon carbide ceramic bodies. Many ceramic materials are prone to deterioration when exposed to oxygen at high temperatures. Low vacuum pre degassing and nitrogen protection sintering reduce the risk of oxidation, and the cost-effectiveness of the equipment is better than that of high vacuum sintering furnaces, making it suitable for formula testing and small-scale trial production. (3). Powder Metallurgy and Metal Materials Iron based and nickel based powder metallurgy parts, refractory metal powders, used for degreasing, pre sintering, and stress relief annealing. (4). Universities and research institutes The laboratory of the School of Materials Science supports new material formula testing, sample sintering, crystallization experiments, and reduction exploration. It supports multi-stage program heating and can store and debug process curves. (5). Catalytic and inorganic functional materials Catalysts, fluorescent powders, porous inorganic materials, complete calcination, activation, and solid-state reaction heat treatment. 3. Advantages of Low Vacuum Atmosphere Furnace Process (1). Vacuum+Atmosphere Dual Mode: It can independently draw low vacuum, or fill with protective gas after vacuuming, and flexibly switch processes. (2). High cost-effectiveness: No need for complex high vacuum units, lower equipment procurement and maintenance costs, fast vacuum pumping speed, and short production/experimental cycles. (3). Flexible temperature control: Multiple programmable heating curves, controllable heating and cooling rates, uniform temperature field, ensuring consistency in sample processing. (4). Effective oxidation prevention: By removing the furnace air in advance and combining it with an inert atmosphere, the problems of high-temperature oxidation, decarburization, and surface pollution of the workpiece are significantly reduced. (5). Customizable configuration: furnace material, maximum temperature, gas path channel, flow meter, explosion-proof device, can be customized according to material and process. 4. Selection and usage tips (1). The vacuum degree of low vacuum atmosphere furnaces is limited. For materials with ultra-high purity, high volatility, and extreme sensitivity to residual gases, it is recommended to use high vacuum furnaces; (2). The process of reducing atmosphere (hydrogen) must confirm that the equipment has explosion-proof design and exhaust gas treatment system; (3). Select heating elements based on the highest temperature of the material: silicon carbon rods are optional for low temperatures, and silicon molybdenum rods are recommended for high temperatures above 1400 ℃; (4). Focus on furnace sealing and accuracy of gas flow meters to prevent atmosphere leakage and excessive oxygen content.

When it is necessary to vacuum or create an atmosphere during the tempering process, you can choose an atmosphere furnace (click on the image to view product details)

The low vacuum atmosphere furnace supports non-standard customization, with optional box and tube structures. The gas path and vacuum system can be customized according to sample size, process temperature, and atmosphere requirements, suitable for laboratory small sample to small batch heat treatment production.Click to learn more customized vacuum atmosphere furnaces! Or click on online customer service to learn more about product information! FAQ Q: Can low vacuum atmosphere furnaces only be filled with nitrogen and argon? A: Basic version supports nitrogen and argon inert atmosphere; After selecting explosion-proof components, a reducing atmosphere such as hydrogen can be used for material reduction processes. Q: How to choose between low vacuum sintering and high vacuum sintering? A: Ordinary ceramics, lithium battery powders, powder metallurgy samples, low vacuum atmosphere furnaces are sufficient for use, with lower costs; For materials with strict impurity control such as high-purity refractory alloys and high-purity aluminum nitride, high vacuum furnaces are recommended.