Unlock instant, AI-driven research and patent intelligence for your innovation.

Low temperature solid reacting method for synthesizing cubic boron nitride

A cubic boron nitride, solid-state reaction technology, applied in the field of materials, can solve the problems of low phase purity of the cubic boron nitride film, reducing the use value of the film, poor crystal quality of the product, etc., achieving easy batch synthesis, low cost, easy effect of operation

Inactive Publication Date: 2010-06-16
SHANDONG UNIV
View PDF1 Cites 9 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

So far, the cubic boron nitride film obtained by this method has low phase purity and large internal stress in the film, which seriously reduces the use value of the film.
Moreover, the vapor phase deposition method has strict requirements on raw materials and expensive equipment, so it is impossible to be used for low-cost and large-scale synthesis of cubic boron nitride; although the solvent synthesis method has potential advantages of uniform particle size, low cost and large-scale preparation, the obtained product crystallization Disadvantages such as poor quality, low phase purity and difficult control of impurities in the product

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
  • Low temperature solid reacting method for synthesizing cubic boron nitride
  • Low temperature solid reacting method for synthesizing cubic boron nitride
  • Low temperature solid reacting method for synthesizing cubic boron nitride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Example 1: First, 0.51g of ammonium fluoroborate (boron source), 1g of sodium azide (nitrogen source), and 0.21g of sodium fluoride (phase inducer) were ground and mixed uniformly and then put into a hot-pressed reactor. 450MPa (hereinafter referred to as the pre-compression pressure of the reaction raw materials) is pre-compressed into blocks and then stops pressurization. When the reactor was heated to 250°C reaction temperature, the pressure was kept constant at 450MPa (hereinafter referred to as the pressure applied during the reaction) for 24 hours, then the heating was stopped and the autoclave was naturally cooled to room temperature. The obtained product was suction-filtered with deionized water and hydrochloric acid successively to remove impurities and by-products, and the product was dried at 60°C to obtain cubic boron nitride.

[0028] The above molar ratio of boron source: nitrogen source: phase inducer = 1:3:1 is referred to as "reaction raw material molar...

Embodiment 2

[0031] Embodiment 2: no phase inducer added

[0032] The synthesis method and process are the same as in Example 1, except that no phase inducer is added, the reaction temperature is reduced to 220° C., the reaction time is extended to 48 hours, and the molar ratio of the reaction materials is 1:3:0. The microscopic morphology of the synthesized cubic boron nitride grains is shown in Figure 6 . The purity of cubic boron nitride is about 76%. Compared with Example 1, the purity of cubic boron nitride is reduced.

Embodiment 3

[0033] Embodiment 3: synthetic method and process are the same as embodiment 1, and difference is that boron source is boron powder, and nitrogen source is lithium nitride, and phase inducer is lithium chloride, and reaction raw material molar ratio is the same as embodiment 1, and reaction raw material The precompression pressure was reduced to 100 MPa, the pressure applied during the reaction was 50 MPa, the reaction temperature was 200° C., and the reaction time was 48 hours. The purity of cubic boron nitride is about 68%.

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

PropertyMeasurementUnit
Granularityaaaaaaaaaa
Login to View More

Abstract

The invention relates to a low temperature solid reacting method for synthesizing cubic boron nitride, which comprises the following steps: after uniformly mixing a boron source, a nitrogen source and a phase inducer in a certain proportion, and putting the mixture into a sealed hot pressing kettle; after pressing the mixture at 100 to 600MPA into blocks, stopping pressing; after heating the hot pressing kettle to the temperature of between 200 and 450 DEG C, pressurizing to between 50 and 650MPa to perform constant temperature reaction for 6 to 48 hours, stopping heating, and naturally cooling down to room temperature; and post-treating the obtained product to obtain the cubic boron nitride. When the cubic boron nitride is synthesized by the method, the operation process is simple, the conditions are mild, and the cubic boron nitride which is approximate to pure phase and has good crystallization can be obtained at low temperature; and the method also has the characteristics of light environmental pollution, low cost, and easy realization of synthesize in batch.

Description

(1) Technical field [0001] The invention relates to a method for synthesizing boron nitride through solid-state reaction under low temperature and middle and low pressure conditions, and utilizing phase induction to promote the formation of cubic boron nitride, which belongs to the field of material technology. (2) Background technology [0002] Cubic boron nitride (cBN) is a synthetic superhard material, its hardness is second only to diamond, but it has better oxidation resistance than diamond, and shows high chemical inertness with iron group elements. Cubic boron nitride has high application value in the fields of materials, semiconductor industry, precision machining and national defense industry. For this reason, people have devoted a lot of energy to the systematic exploration of the synthesis methods of cubic boron nitride, which mainly include high temperature and high pressure methods, vapor phase deposition methods, and solvothermal synthesis methods and so on. A...

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): C01B21/064
Inventor 廉刚张晓崔得良王琪珑
Owner SHANDONG UNIV