Method for doping polycrystalline alumina ceramics

A polycrystalline alumina and alumina technology, which is applied in the field of ceramic manufacturing, can solve the problems of difficulty in mixing, affecting lamp life, light efficiency, and the effect cannot meet the predetermined requirements, and achieves uniform distribution, high speed and large output. Effect

Inactive Publication Date: 2008-04-09
SHANGHAI YAMING LIGHTING
View PDF0 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Because there is metal halide in the discharge tube of the ceramic metal halide lamp, and it will react with magnesium oxide, affecting the life of the lamp, light effect, etc., so the amount should be a

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for doping polycrystalline alumina ceramics

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0013] The doping method of the present invention is that the alumina product is formed first and then initially fired to increase the mechanical strength. The initial firing temperature is 900°C-1250°C for 1-2 hours; Put it in a perforated container 2 shown in Figure 1, and then place it in a semi-closed container 1, the semi-closed container 1 is filled with impurities that need to be added, and spread around the perforated container 2, At this time, the impurities and the product are separated by the container 2 with holes, and then they are sent together to a high-temperature furnace for heating at a temperature of 800°C to 1500°C for 2 to 5 hours. During this process, the impurities are heated and become The steam passes through the small holes and spreads evenly on the product; then the alumina product with impurities is heated for the third time, at this time, the temperature is 1700°C-2000°C, and the time is 10-12 hours, and the impurities are completely fused into it ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a method of doping in polycrystal alumina ceramics, including the following steps: the alumina product is formed first and is initially burnt under the temperature of 900 DEG C to 1,250 DEG C for one or two hours; then the burnt alumina product is put together with the impurity but the two do not contact directly, and then are heated to 800 -1,500 DEG C for two hours to five hours, thereby ensuring that impurity is heated and changed into steam which is evenly distributed on an alumina product; last, the alumina product with the impurity is heated for a third time to 1,700 to 2,000 DEG C for 10 hours to 12 hours. The invention adopting steam doping can keep the distribution of impurities more even, in particular suitable for the doping of impurity in small quantity. The invention has the advantages of mechanical production, fast speed and large yield, etc. in comparison with prior slurry blending doping patterns.

Description

technical field [0001] The invention relates to a method for manufacturing ceramics, in particular to a method for adding a small amount of auxiliary materials to polycrystalline alumina ceramics. Background technique [0002] In high intensity discharge lamps, translucent polycrystalline alumina (PCA) is used as the arc tube material. The production process of PCA includes the following basic steps: mixing, molding and pre-densification, and solid-state sintering. Among them, the mixing is to add additives, binders and other chemicals that are beneficial to molding, such as dispersants, defoamers, lubricants, etc. We mostly use high-purity ultra-fine alumina powder as raw material, add appropriate amount of rare earth compound, and add water ball to grind into slurry to complete the mixing. In the production of ceramic discharge tubes, in order to obtain more uniform grains, magnesium oxide should be added to the alumina powder. Because there is metal halide in the disch...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C04B35/10C04B35/63
Inventor 黄海杰
Owner SHANGHAI YAMING LIGHTING
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap