Five key points to help you quickly solve problems using vacuum tungsten furnaces

Brother Furnace's vacuum sintering furnace series products combine high melting point adaptability with high-precision control performance, earning the trust of customers across various industries.

We offer a variety of products such as vacuum graphite sintering furnaces, vacuum ceramic fiber thermal sintering furnaces, and vacuum atmosphere sintering furnaces. These products are precisely tailored to different material characteristics and process requirements, providing high-quality, comprehensive solutions for various sintering scenarios.

The vacuum tungsten wire sintering furnace, leveraging the ultra-high melting point of tungsten wire (3422℃), is specifically designed for the high-temperature sintering needs of high-melting-point materials such as metals and ceramics, making it one of the key pieces of equipment in this field.

1. Temperature Control System: Precise Control of the Tungsten Wire Thermal Field

1.1Uneven heating of tungsten wire and local overheating

Problem: Uneven spacing of the tungsten filaments and large differences in resistivity in some areas lead to significant temperature deviations within the furnace, causing abnormal reddening of the tungsten filaments in certain regions.

Solution: Open the chamber cavity, readjust the tungsten filament spacing, and further optimize according to the furnace type to ensure uniform heat radiation.

Replacing the filament with high-purity tungsten wire avoids uneven heating due to material differences.

Its compatibility also covers the similar heating needs of other vacuum furnaces.

1.2Temperature runaway inside the vacuum tungsten filament chamber

Problem: Thermocouple malfunctions are often caused by tungsten-rhenium thermocouples, mismatches between process parameters and tungsten wire power, resulting in actual temperatures far exceeding the set values, or abnormal heating rates.

Solution: Check for broken thermocouple wires and damaged insulating ceramic tubes; replace with high-temperature tungsten-rhenium thermocouples. Recalibrate process parameters to avoid excessively rapid heating.

2. Circuit system of vacuum tungsten filament furnace

2.1Tungsten wire short circuit or burnout

Problem: The circuit breaker trips after heating is started, and the tungsten wire is partially melted.

Solution: Replace the damaged insulating ceramic tube and base to ensure insulation between the tungsten wire and the furnace body; adjust the spacing of the tungsten wires and fix them with high-temperature-resistant ceramic supports to prevent contact due to thermal deformation.

2.2The heating power of the vacuum tungsten filament furnace is insufficient

Problem: Slow heating, unable to reach the target temperature.

Solution: Calculate the total power of the tungsten filament and replace the transformer with one of matching capacity according to the furnace type.

The power configuration of the vacuum autoclave can refer to this calculation logic.

3. Chamber and vacuum system of the vacuum tungsten furnace

3.1Tungsten filament volatilization and furnace contamination

Problem: Black tungsten vapor deposits adhere to the inner wall of the furnace, contaminating the surface of sintered products.

Solution: Overhaul the vacuum pump unit, such as replacing the diffusion pump oil and cleaning the vacuum pump, to improve the vacuum holding capacity of the vacuum tungsten filament furnace.

This standard can be followed for the maintenance of the vacuum system of the vacuum sintering furnace.

3.2Chamber deformation and cracking

Problem: The chamber deforms at high temperatures, causing a disordered tungsten filament arrangement.

Solution: Optimize the chamber structure, adopting a segmented or reinforced design to distribute thermal stress; strictly control the heating rate, adjusting the holding time during the high-temperature stage according to the material to reduce furnace chamber wear.

4. Gas path system of vacuum tungsten filament furnace

4.1Hydrogen pipeline seal failure

Problem: The hydrogen pipeline uses stainless steel double-ferrule fittings, and leaks pose a safety hazard and cause atmosphere contamination.

Solution: Replace with VCR-specific fittings strictly according to Chinese standards to ensure a tight seal for ultra-high purity hydrogen.

4.2Gas flow fluctuations and leaks

Problem: Hydrogen leakage at the float flowmeter connector causes unstable flow, affecting the sintering atmosphere.

Solution: Replace with a high-precision mass flowmeter. All gas pipelines must undergo helium mass spectrometry leak testing after installation; this is a mandatory quality control item. Leak testing of the gas lines in the vacuum atmosphere sintering furnace should also be performed according to this standard.

5. Unique processing issues of tungsten wire

5.1Aging of tungsten wires in the chamber

Problem: Tungsten wires break after only a few uses, resulting in high sintering costs.

Solution: Optimize the sintering curve and regularly clean the surface of the tungsten wires to remove the oxide layer.

5.2"Tungsten contamination" in sintered products

Problem: Tungsten particles remain on the product surface, affecting performance.

Solution: Add a molybdenum shield between the tungsten filament and the product to prevent tungsten vapor from directly contacting the product; Use a furnace lining with high adsorption capacity, such as activated carbon-coated graphite, to adsorb tungsten volatiles.

Brother Furnace: Your Best Partner

Troubleshooting vacuum tungsten filament sintering furnaces requires a close understanding of the high-temperature characteristics of tungsten filaments and the stringent requirements of the vacuum system; each aspect needs targeted optimization. Understanding these solutions will ensure smooth operation.

If you require more information on high-quality sintering furnaces, please contact us. Brother Furnace is a professional manufacturer of vacuum electric furnaces, and we provide you an excellent service.