Al2O3 Alumina Metallization of Ceramics for Vacuum Interrupter

Product Description

Al2O3 Alumina Metallization of Ceramics for Vacuum Interrupter

Product Introduction

What are Ceramic Structural Parts

Ceramic structural parts are also called precision ceramic parts. The products mainly include high-voltage electrical insulators, pump components, nozzles, ceramic bearings, and dielectric components for semiconductor wafer processing.

In order to achieve the precision of the product, most ceramic structural parts need further finishing treatment after the sintering process is completed.

What is Metallization of Ceramic Structural Parts?

Metallization of ceramic structural parts refers to the creation of thin metal layers (films) on the surface of ceramic structural parts.

Ceramic surface metallization combines the good mechanical properties of ceramics and the excellent electrical and thermal conductivity of metal materials.

It not only has the excellent properties of high strength, high wear resistance, high temperature resistance and small thermal expansion coefficient of ceramic materials, but also has the plasticity and toughness properties of metal materials.

Is it Good to Use Ceramic Structural Parts?

You can see the advantages of ceramic structural parts through the comparative table between different material structural parts.
 

Property	Ceramic	Metal	Polymer
Hardness	High	Low	Bad
Elastic Modulus	High	Good	Low
High Temperature Resistance	High	Low	Bad
Thermal Expansion	Low	Good	Good
Malleability	Low	Good	Good
Corrosion Resistance	Good	Low	Low
Electrical Conductivity	Low	Good	Low
Density	Average	High	Low
Thermal Conductivity	Average	Good	Low

Production Process

Our product production is mainly divided into 3 steps, forming - finishing - metallization. The production flow chart is shown below.


About Forming Method

There are mainly Dry Pressing, Hot Pressing, Isostatic Pressing, and Ceramic Injection Molding (CIM), each of which has its own advantages and disadvantages. We will choose the most suitable forming method on the basis of saving costs and ensuring quality.

About Finishing Process

In order to achieve the precision of the product, most ceramic structural parts need further finishing treatment after the sintering process. The main finishing processes we use are machining (lapping, polishing...) and glazing.

About Metallization Process

After the surface of the ceramic material is metallized, it has both the characteristics of ceramics and the properties of metal.

Introduction to Silver Firing Method

There are many methods for surface metallization of ceramic structural parts, and here we will focus on the silver firing method. The brief process of silver firing method is shown in the picture below.


The sintering mechanism of the silver firing method is:

1. Reducing silver-containing raw materials into silver particles.
2. Melting the solvent into a melt.
3. The melt bonds the silver particles together to form a silver layer.
4. The silver layer is fixed on the ceramic surface.

The fired silver layer is firmly bonded, the thermal expansion coefficient is close to that of the ceramic, and the thermal stability is good. In addition, the firing temperature is low, and the requirements on the atmosphere are not strict; the firing process is simple and easy.

Product Applications

Application of  Al2O3 Structural Parts

1. Semiconductor equipment parts

2. Medical equipment parts

3. Industrial equipment parts

4. Wafer handling parts

5. Insulation shells for electronic devices

Product Parameters

Category	Property	Unit	99.8% Al2O3	99.5% Al2O3	99% Al2O3	95% Al2O3	94.4% Al2O3
Mechanical	Density	g/cm^3	≥3.95	≥3.90	≥3.85	≥3.65	≥3.60
	Water absorption	%	0	0	0	0	0
	Vickers hardness	HV	1700	1700	1700	1500	1500
	Flexural strength	Mpa	≥ 390	≥ 379	≥ 338	≥ 320	≥ 312
	Compressive strength	Mpa	≥ 2650	≥ 2240	≥ 2240	≥ 2000	≥ 2000
	Fracture toughness	Mpam^1/2	4-5	4-5	4-5	3-4	3-4
Thermal	Max. Service temperature (non-loading)	ºC	1750	1675	1600	1500	1500
	CTE (Coefficient of thermal expansion) 20-800ºC	1×10^-6/ºC	6.5-8.2	6.5-8.0	6.2-8.0	5.0-8.0	5.0-8.0
	Thermal shock	T (ºC)	≥ 200	≥ 200	≥ 200	≥ 220	≥ 220
	Thermal conductivity 25ºC	W/(m·k)	31	30	29	24	22.4
	Specific heat	1×10^3J/(kg·k)	0.78	0.78	0.78	0.78	0.78
Electrical	Volume resistivity 25ºC	ohm·cm	> 1×10^14	> 1×10^14	> 1×10^14	> 1×10^14	> 1×10^14
	300ºC		1×10^12	1×10^12	8×10^11	10^12-10^13	10^12-10^13
	500ºC		2×10^12	5×10^10	2×10^9	1×10^9	1×10^9
	Dielectric strength	KV/mm	20	19	18	18	18
	Dielectric constant (1Mhz)	(E)	9.8	9.7	9.5	9.5	9.5

Product Recommendations

Jinghui is an enterprise specializing in the research and production of precision ceramics. Metallized ceramics are our superior products. They have excellent high-frequency and high-voltage insulation properties, high sealing strength, and good vacuum airtightness. We hope that we will do our best to improve your product performance and reduce production costs with years of practical experience.

Our Advantages

Jinghui has accumulated more than ten years of experience in the field of metallized ceramic structural parts, and can produce various specifications of metallized ceramic structural parts according to customers' drawings, with superior performance. Our customers are very recognized for our product quality.