High Purity ZrB2 Powder via Electron Beam Melting and Segmentation
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Solution Overview
Problem
The existing methods for manufacturing ZrB2 single crystal substrates face challenges in achieving high purity ZrB2 powder, leading to low manufacturing efficiency and difficulty in producing large single crystals due to impurities like C, HfC, TiC, and ZrC, which are not effectively removed in conventional processes.
Innovation Solution
A method involving electron beam melting of Zr sponge to produce a high-purity ingot, followed by hydrogenation, pulverization, dehydrogenation, and high-temperature oxidation to create a ZrO2 powder, which is then reduced with boron to produce a ZrB2 powder with a purity of 99.9 wt % or higher, excluding C and gas components, and minimizing impurities like Hf, Ti, Fe, Cr, and Nb.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional reduction methods using B4C and C are used to manufacture ZrB2 powder, then the manufacturing process is simple, but the purity is insufficient due to large amounts of C and impurities like Si and Fe being mixed in
Solution Approach 1:
The manufacturing process is divided into multiple sequential steps: electron beam melting of Zr sponge, hydrogenation to ZrH2, pulverization, dehydrogenation to Zr powder, oxidation to ZrO2, and finally reduction with B. This segmentation allows each step to be optimized for purity, removing impurities at different stages rather than relying on a single reduction step that introduces carbon contamination.
Solution Approach 2:
The patent uses intermediate compounds (ZrH2, Zr powder, ZrO2) as mediators to transform the raw Zr sponge into pure ZrB2. These intermediaries allow for systematic purification at each transformation stage, avoiding direct reduction with carbon-containing materials that would contaminate the final product.
2Manufacturing precision
If high purity ZrB2 powder is required for single crystal substrate manufacturing, then the quality of substrate improves, but the manufacturing efficiency decreases and large single crystals cannot be produced
Solution Approach 1:
The patent replaces conventional mechanical/chemical reduction methods with electron beam melting and high-temperature oxidation processes. This substitution enables achieving ultra-high purity (99.9 wt% or higher) without the carbon contamination inherent in carbon-based reduction methods, thereby enabling both high purity and efficient production of large single crystals.
Solution Approach 2:
The patent employs extreme parameter conditions (electron beam energy, high temperature oxidation at 800-1000°C) to achieve phase transformations and purification. By controlling temperature, atmosphere, and energy input parameters, the process achieves high purity ZrB2 powder that supports efficient single crystal growth.
3Ease of manufacture
If conventional FZ method is used for single crystal substrate manufacturing, then the existing process can be maintained, but the purity of ZrB2 powder is inferior and large single crystals cannot be manufactured
Solution Approach 1:
The patent performs preliminary purification actions before the FZ method by producing ultra-high purity ZrB2 powder through electron beam melting, hydrogenation, dehydrogenation, and oxidation processes. This preliminary purification ensures that the starting material for FZ method has sufficient purity (99.9 wt% or higher) to grow large, high-quality single crystals without contamination from conventional reduction methods.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in a high-purity ZrB2 powder that enables efficient production of large single crystals with reduced manufacturing costs and improved purity, enhancing the efficiency of the Floating Zone Method for substrate manufacturing.
Implementation Method 1
subjecting a Zr sponge raw material to electron beam melting and casting to prepare an ingot
Implementation Method 2
hydrogenating the cut powder into ZrH2
Implementation Method 3
pulverizing and dehydrogenating the resultant product into a Zr powder
Implementation Method 4
oxidizing the Zr powder at a high temperature in an oxygen atmosphere into a ZrO2 fine powder
Implementation Method 5
mixing the ZrO2 fine powder with B so as to reduce ZrO2 and obtain a ZrB2 powder
Data Source
AI summary
A high purity ZrB2 powder having a purity of 99.9 wt % or higher excluding C and gas components, and a manufacturing method of such high purity ZrB2 powder, including the steps of: subjecting a Zr sponge raw material to electron beam melting and casting to prepare an ingot having a purity of 99.9 wt % or higher; cutting the ingot into a cut powder and hydrogenating the cut powder into ZrH2; pulverizing and dehydrogenating the resultant product into a Zr powder and oxidizing the Zr powder at a high temperature in an oxygen atmosphere into a ZrO2 fine powder; and mixing the ZrO2 fine powder with B having a purity of 99.9 wt % or higher so as to reduce ZrO2 and obtain a ZrB2 powder having a purity of 99.9 wt % or higher. Purity of the ZrB2 powder for use in sintering is made to be 99.9 wt % or higher, which is required in the manufacture of a ZrB2 single crystal substrate with the high frequency induction heating FZ method (Floating Zone Method), and it is thereby possible to obtain a high purity ZrB2 powder and the manufacturing method thereof enabling the enlargement of a ZrB2 single crystal substrate and reduction in the manufacturing costs associated therewith.