The Study Of The Technology Of Synthesizing Big Particle And High-grade Diamond And Its Application

As a kind of two type super-hard materials of artificial synthesis, industrial diamond has superior properties and a very important status that cannot been replaced by other materials,to be increasingly applied.At present, using powder catalyst and enlarging equipment is two great evolvements of the technical of synthesizing diamond in china. But there is some deficiency in the synthesizing technology of diamond corresponding using powder catalyst with enlarging equipment, especially in the synthesizing technology of the big particle and high-grade diamond.Cubic press is an equipment made in china in independence.The synthesizing technology of the big particle and high-grade diamond has becomed a important direction to people for more than forty years .The primary problem is that the product granularity is hard to satisfy to the market, to hamper the diamond industry developing. Therefore, it becomes great importance to study the synthesis of the big particle and high-grade diamond in cubic press.In light of the present state and existing problems of diamond synthesizing research in the equipment, synthesis and materials, on the basis of tutor's right guidance and the predecessor's studying, the author conducts an investigation into the research topic in this paper. Research works as follow:1. The paper has systematically investigated the actions and influences of the materials such as pyrophyllite, catalyst and graphite on the synthesizing of industical diamond and its properties.2. Experiments and studies have been down on the sythesis of the big and high-grade diamond from equipments, design of the reaction vessels and parameters of technology.3. The studies have been made on the manufacture of tools with the synthesized high-grade diamond and applications of the corresponding tools.The innovations include:1. A suit of theory, based on the experiment and the analysis of (?) 23mm reaction vessels, which scales the ultra-high pressure vessel's pressurizing and pressure transfering in the cubic press, has been reported. The theory considers that the ^λ_max can not exceed 29.49%, and smaller theλ, better the pressurizion; theâ–³_min can not be less than 3.316mm, and bigger theâ–³, better the pressure transfering. The main dimensions of (?) 39mm reaction vessel, including anvil, a=47mm, b=15mm,α=42°, pyrophyllite, L₀=59mm, has been designed by applying the theory.2. A fetting which controls press and temperature to synthesizing of diamond has been made out.The result shows that the fetting can better control the prerequisite press and temperature and optimize synthesizing process. The fetting is adaptable to synthesizing of big particle and high-grade diamond.3. Under the stability of the synthesis, the paper improves on the process of the large pyrophyllite block's baking and roasting, the result shows that it is greatly improves the stability of the synthesis.4. The making technology of the powder synthesizing block is important to the diamond quantity and abilities. When the proportion of the catalyst and graphite is 7:3, more bigger the density of the powder synthesizing block, more better the quantity and quality of diamond.5. The result of the study of Fe₇₀Ni₃₀ powder catalyst for present industrial diamond shows that Fe₇₀Ni₃₀ powder catalyst is a better material to synthesize big particle and high-grade diamond.6. Applying the principle of the diamond growing and the controlling fetting made in independence, the synthesizing experiment was performed to keep diamond's growing time reaching 28min using the powder synthesizing technology and diamond of 30^# -40^# mesh size has been synthesized and its pick-up ratio is exceeding 30%, and its TTI reachs 80%.7. The big particle and high-grade diamond had been synthesized by the equipment and synthesizing process hereinbefore, and its application is potential in drilling bits and saws and so on.