Do you know the principle of rapid cooling in a sintering furnace?

2026-05-02 09:59:26

A sintering furnace is a specialized piece of equipment used to enable powder compacts to achieve the required physical and mechanical properties as well as microstructure through the sintering process. sintering furnaces are used to dry pastes on silicon wafers, remove organic components from the pastes, and complete aluminum back-surface field and grid line sintering.

Negative pressure debinding involves filling the furnace with gas via a flow meter while simultaneously evacuating with a slide valve pump. During heating, the gas flow removes binders from the product. Vacuum internal sintering is performed without gas filling; the slide valve pump continuously evacuates while the furnace heats up, sintering under vacuum. Partial pressure sintering involves introducing gas to maintain a certain pressure while the furnace heats up, sintering under partial pressure. Forced cooling rapidly introduces gas, activates a fan, and circulates the gas inside the furnace, carrying heat away via cooling water.

To ensure smooth dewaxing (of lubricants or binders), reduction, alloying, and microstructure transformation of powder compacts during sintering, precise control is required over sintering temperature, protective atmosphere, compact transport method, heating and cooling rates, etc.

Therefore, a Sintering furnace must meet the following structural requirements:

(1) A welldeveloped lubricant burningoff device (commonly called a dewaxing zone).
(2) Airtightness – it must isolate the furnace from outside air and ensure the smooth flow of protective atmosphere inside.
(3) Controllable temperature in each zone and adjustable sintering atmosphere.
(4) A rapid cooling device capable of quickly cooling sintered parts to the exit temperature without oxidation.

The sintering heat treatment furnace is a widely used hightemperature heat treatment device in the powder metallurgy industry. After workpieces are sintered at high temperature in the furnace chamber, they must be cooled by a cooling device. Generally, the cooling device of a sintering furnace is a waterjacketed cooling jacket (called a cooling water tank) using water as the cooling medium. When workpieces move from the furnace chamber into the cooling water tank, they release a large amount of heat, which is radiated or transferred to the cooling water. Typically, the cooling water that has absorbed a great deal of heat is cooled via various pathways while a large amount of heat is discharged into the atmosphere – wasting energy and causing thermal pollution. In a lowcarbon economy, saving energy and reducing emissions is everyone’s duty. Designing and manufacturing a heat utilization device for sintering furnace cooling water would both make use of energy and reduce emissions – a perfect winwin.

Operating principle of cooling water circulation in a sintering heat treatment furnace

The furnace chamber is equipped with a first cooling water tank, a second cooling water tank, and a third cooling water tank in sequence. The usual cooling principle is: the third cooling water tank is connected to the second cooling water tank via a hose; the second cooling water tank is connected to a hot water outlet pipe; the hot water outlet pipe is connected to a cooling tower; the cooling tower is connected to a water reservoir; the water reservoir is connected to a water pump; the water pump is connected to a cold water pipe; the cold water pipe is connected to a water tower; the water tower is connected to a cooling water inlet pipe; and the cooling water inlet pipe is connected to the third cooling water tank. Heat radiated from the workpieces is carried away by the flowing water to the pipes and the cooling tower, where it is dissipated into the atmosphere. The cooled water, serving as the cooling medium, circulates along the direction indicated by arrows, absorbing heat from the hightemperature workpieces in the cooling tank, and continues to be recycled.

Working process of the sintering heat treatment furnace

The distinctive feature of this device is: the hot water outlet pipe is also connected to a分流管 (branch pipe); the branch pipe is connected to a water storage tank; the water storage tank is connected to a hot water inlet pipe; the hot water inlet pipe is connected to the first cooling water tank; the first cooling water tank is connected to a steam pipe; and the steam pipe is connected to a workstation. A water pump and a valve are installed between the branch pipe and the water storage tank, and also between the water storage tank and the first cooling water tank. A water level gauge is mounted on the side of the first cooling water tank, a drain pipe at the bottom, and a heating device and a safety valve on the top. The functional principle of this special device is similar to that of a small boiler. Cooling water at a certain temperature flows through a series of paths and enters the first cooling water tank. When hightemperature sintered workpieces move from the furnace chamber into the first cooling water tank, they release a large amount of heat. The cooling water absorbs the heat and turns into steam, which flows through the steam pipe to a workstation for use in production and daily life, thereby achieving energy saving and emission reduction.

Zhuzhou Hechuang HighFrequency Equipment Co., Ltd. is a hightech company integrating R&D, production, and service, based on semiconductor power conversion technology. The company’s products are mainly used in industries such as newtype thermally conductive materials, special ceramic hightemperature sintering, carbon materials, battery anode materials, graphite materials, heat treatment processing, and semiconductor purification. The company’s main products, which are actively serving various industries, include: hightemperature Graphitization furnaces, special ceramic sintering furnaces, Vacuum brazing furnaces, vacuum sintering furnaces, crystal sintering furnaces, chemical Vapor deposition furnaces, hotpressing sintering furnaces, vacuum pyrolysis furnaces, and complete sets of induction Heating Equipment, as well as nonstandard vacuum or atmosphere electric heating equipment.

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