Can a multi zone rotary electric furnace be used for sintering experiments?

The experimental multi temperature zone rotary electric furnace can be fully used for sintering experiments. Its core functions such as independent temperature control, rotation design, and atmosphere control in multiple temperature zones are highly matched with the requirements of sintering process for temperature uniformity, atmosphere protection, and gradient heat treatment, which can significantly improve the density, uniformity, and performance stability of sintered bodies. The following analysis is conducted from three dimensions: technical principles, experimental advantages, and typical applications:

1. Technical principle: The alignment between the core requirements of sintering process and the functions of electric furnace
Sintering is a process in which powder or granular materials undergo interparticle bonding, pore reduction, and density increase through high-temperature heating. Its key requirements include:
Accurate temperature control: It is necessary to control the heating rate, insulation time, and cooling rate in stages to avoid cracking or abnormal grain growth caused by thermal stress.
Uniform thermal field distribution: prevents local overheating or excessive temperature gradient, ensuring synchronous shrinkage of all parts of the material.
Controllable atmospheric environment: prevents oxidation or promotes specific reactions (such as sintering of metal powders in a reducing atmosphere).
Material uniformity: Avoid particle settling or segregation to ensure component uniformity.
Corresponding functions of multi temperature zone rotary electric furnace:
Multi zone independent temperature control: Different temperature curves can be set for different temperature zones (such as the fast heating zone in the front section, the insulation zone in the middle section, and the slow cooling zone in the back section) to achieve gradient heat treatment.
Rotating design: By rotating the furnace tube, the material is rolled, eliminating temperature unevenness and promoting uniform particle contact.
Atmosphere control: supports inert gases (N ₂ Ar）、 Reductive gas (H ₂) or vacuum environment to prevent oxidation or promote reactions.
High precision temperature control: The temperature control accuracy reaches ± 1 ℃, and with fuzzy PID control, the temperature fluctuation is small.

2.Experimental advantage: key indicator for improving sintering quality
Significant increase in density
Rotation promotes particle rearrangement: In ceramic sintering, rotation causes powder particles to continuously roll, reducing pores and increasing packing density. For example, alumina ceramics have a higher density after sintering, which is higher than that of static sintering.
Inhibiting abnormal grain growth: By gradient temperature control (such as rapid heating at 1200 ℃ in the front section, insulation at 1500 ℃ in the middle section, and slow cooling at 1000 ℃ in the back section), the grain size distribution is controlled to avoid local overheating leading to grain coarsening. A study shows that the standard deviation of grain size in ZrO ₂ ceramics sintered by rotation decreases.
Optimization of component uniformity
Preventing particle settling: In the sintering of metal ceramic composite materials, rotation ensures uniform distribution of components with different densities. For example, after sintering of Al ₂ O ∝ – TiC composite materials, the uniformity (standard deviation) of TiC particle distribution decreases.
Promote liquid phase diffusion: In ceramic sintering containing glass phase, rotation accelerates the flow of liquid phase and increases the densification rate. A certain experiment shows that the porosity of borate glass ceramics sintered by rotation decreases and the time is shortened.
Enhanced atmosphere protection effect
Inert atmosphere oxidation prevention: In metal powder sintering, the introduction of high-purity Ar (99.999%) can completely isolate oxygen and reduce the thickness of the surface oxide layer.
Reductive atmosphere promotes reaction: In the sintering of MoSi ₂ ceramics, the H ₂/Ar mixed atmosphere (ratio 1:9) can reduce surface oxides, promote densification, and increase relative density.
Thermal stress control
Gradient cooling reduces cracking: Slowly cool the lower temperature zone in the later stage (such as 5 ℃/min), rotate to evenly lower the temperature, and avoid local shrinkage differences that may cause cracking. The cracking rate decreases in the sintering of Si ∝ N ₄ ceramics.

3. Typical application: Covering multiple types of material sintering scenarios
Advanced Ceramic Sintering
Alumina ceramics: After rotary sintering, they have high density and improved bending strength, and are used for semiconductor packaging substrates.
Silicon nitride ceramics: sintered by rotating in a H ₂/N ₂ mixed atmosphere, with high relative density and improved fracture toughness, used for bearing balls.
Metal powder sintering
316L stainless steel: Rotary sintering under Ar atmosphere, with higher density and greatly improved hardness, used for medical implants.
Titanium alloy: High tensile strength and increased elongation after vacuum rotary sintering, used for aerospace components.
Composite material sintering
Al ₂ O ∝ – TiC: After rotary sintering, the hardness is increased and the wear resistance is increased by three times. It is used for cutting tools.
C/C composite material: By rotating immersion carbonization cycle in Ar atmosphere, the density and thermal conductivity are increased, and it is used for rocket throat lining.
Sintering of functional materials
Piezoelectric ceramics (PZT): After rotary sintering, the dielectric constant and piezoelectric coefficient increase, and it is used for ultrasonic transducers.
Transparent ceramic (YAG): By vacuum rotary sintering, the transmittance is improved, and it is used as a laser window material.