What Process or Structural Adjustments are Required for Vacuum Sintering Furnaces to Ensure Sintering Quality for Materials Containing Volatile Components?
Release time:
2025-11-17
Author:
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Abstract
1、 Key process adjustments
Segmented temperature control and pre degreasing process:
During the heating stage, a low-temperature preheating (degreasing) section is set up, usually kept at 300-600 ℃ for a long time (1-4 hours), to slow down the decomposition and smooth discharge of volatile substances, and to avoid internal pressure caused by instantaneous gasification at high temperatures. Multiple step heating can be used to control the heating rate (such as 1-3 ℃/min) and achieve "slow volatilization".
Vacuum degree is controlled in stages:
In the initial stage, micro vacuum or low vacuum (such as 10-100Pa) or the introduction of inert gas (such as argon) can be used for positive or negative pressure circulation to suppress the violent volatilization of volatile substances. After the volatile matter is basically discharged, draw high vacuum (≤ 10 ⁻ ² Pa) for high-temperature sintering to ensure densification.
Extend insulation time:
Extend the insulation time appropriately during the degreasing stage and the initial sintering stage to ensure sufficient discharge of volatile substances and avoid the formation of closed pores inside the billet.
2、 Optimization of Equipment Structure and Auxiliary Systems
Configure a cold trap (condenser):
Install a cold trap at the front end of the vacuum pipeline or furnace body to collect volatile organic matter, grease, or moisture through low temperature (such as liquid nitrogen cooling) condensation, preventing them from entering the vacuum pump and causing oil pollution or damage to the pump body, while reducing the risk of reflux.
Enhance exhaust capacity:
Select a high-speed vacuum pump set (such as a molecular pump+mechanical pump) and optimize the exhaust pipe design to reduce flow resistance, ensure timely discharge of volatile gases, and avoid accumulation in the furnace.
Furnace airflow design:
For large furnaces, the introduction of controllable inert gas flushing (such as Ar gas blowing) can be considered to promote the directional discharge of volatile substances and improve the efficiency of degreasing.
Monitoring system:
Install vacuum gauges, residual gas analyzers (RGA), or pressure rise rate testing functions to monitor the volatilization process in real time, determine whether degreasing is complete, and achieve intelligent process control.
In summary, through a comprehensive strategy of "slow heating, controlled vacuum, staged, and strong exhaust", combined with auxiliary devices such as cold traps, the release process of volatile substances can be effectively managed to ensure the sintering quality and equipment safety of materials containing volatile components.
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2022-07-28
2025-11-24
Zhuzhou Chi Carbon Automation Equipment Co., Ltd
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