A method of preparation of boride molybdenum powder preparation steps in the synthesis of high temperature and high pressure way, according to the synthetic before B/Mo mole ratio of n (n = 0.5, 1, 2, 2.5, 4) Settings, in full compliance with material control design phase of boride molybdenum powder, achieve the boride phase of molybdenum materials synthesis and controllable, and synthesis of boride molybdenum powder granularity and the crystal grain size is complete, excellent performance. The method has the advantages of controllable process, short process route, strong target, convenient operation, high efficiency, energy saving, safety and reliability. The finished product molybdenum boride powder has uniform particle size distribution, complete crystal crystal, chemical purity ≥99.8%, and good quality stability. Compared with the molybdenum boride material synthesized by conventional methods, the performance has been significantly improved, which makes the produced molybdenum boride material show excellent physical and chemical properties in industrial applications.
Boride molybdenum compounds with high melting point, high hardness, wear resistance, high temperature resistant, corrosion candle and low friction coefficient, etc, has the extremely important status in modern industry, are widely used in metal materials, coating materials, high temperature structural materials, the cathode material, corrosion resistant, wear resistant materials and other fields, and with the progress of science and technology, boride molybdenum compound applications will also be further expanded, the material will show more excellent application value and great market prospect. According to the binary phase diagram of mo-b, molybdenum boride compounds can exist in six phases: Mo2B, mo-mob, mob-mob, MoB2, Mo2B5 and MoB4. At present, the domestic and foreign research on B – Mo compounds reported less, gao Yang of dalian maritime university institute of metal materials in the sixth international hot spraying discussion papers, published an article entitled “explosion spraying molybdenum metal boride ceramic coating the formation process of” academic papers, in the paper the author USES the sintering production process preparation for 5 to 10 microns and 10 to 30 microns of two kinds of MoB powder, but is contained in the synthesis of powder X-ray diffraction show that alpha MoB, beta MoB, MoB2 and Mo2B5 several phase, this has not been a single MoB phase of powder, This to some extent limits the practical application of the material in production technology. Wang Yadong of the wuhan university of technology, and others in the Chinese science bulletin, 2012, 57 (27) published an article entitled “the preparation of aqueous solution metal boride as anode materials and the capacity of output performance” of academic papers, the author through the mechanical ball grinding mole ratio for the 1-0. 5 Mo powder with B powder synthesis for amorphous MoB0.5 and elemental Mo mixture, still didn’t get a single phase of molybdenum boride, and MoB0.5 still exists in the form of amorphous.
Technical protection point
A method for preparing molybdenum boride powder, which comprises the following steps: Step 1. Take B powder and place it in a graphite crucible coated with BN powder on the inner wall. Then, place the graphite crucible in a hydrogen reduction furnace at 1000 Reduction at 1500 ° C to obtain reduced B powder, ready for use; Step 2. Take Mo powder and place it in a metal molybdenum crucible. After that, place the metal molybdenum crucible in a hydrogen reduction furnace and perform the reduction at 600 1200 ° C. The reduced Mo powder is obtained and is ready for use. Step three: According to the molar ratio of B and Mo is 0.5 or 1 or 2 or 2.5 or 4, respectively, weigh the reduced B powder obtained in step 1 and the reduced Mo obtained in step 2. Add the powder to the ball mill tank and perform ball milling for 2.96 h. Step 4: Pour the ball milled material from Step 3 into a stainless steel tray. Then, place the tray in a vacuum drying box and dry at 60.120 ° C. Step 5: The material obtained after drying in Step 4 is transferred to a graphite crucible coated with BN powder on the inner wall, and then the graphite crucible is placed in a vacuum furnace under the condition that the pressure in the vacuum furnace is controlled to 0.5.30 GPa. 0.5-30 ° C / min The temperature rate was raised to 800 · 2400 ℃, and the sintering was performed for 0.5 · 8h to obtain molybdenum boride particles, which are reserved for use. Step 6. Put the molybdenum boride particles obtained in step 5 into a pulverizer and pulverize them into powder. The particle size distribution requires selecting a sieve with a suitable mesh number for screening, that is, to obtain a molybdenum boride powder with a molar ratio of B and Mo of 0.5 or 1 or 2 or 2.5 or 4 …
[Summary of Technical Features]
A method for preparing molybdenum boride powder, comprising the following steps: Step 1: taking powder B and placing it in a graphite crucible coated with BN powder on the inner wall, and then placing the graphite crucible in a hydrogen reduction furnace, The reduction is performed at 1000-1500 ° C to obtain reduced B powder, which is reserved. Step 2: Take Mo powder and place it in a metal molybdenum crucible. Then, place the metal molybdenum crucible in a hydrogen reduction furnace at 600-1200 ° C. The reduction is carried out to obtain reduced Mo powder, which is reserved; step three: According to the molar ratio of B and Mo is 0.5 or 1 or 2 or 2.5 or 4, respectively, weigh the reduced B powder obtained in step 1 and the obtained in step 2 respectively. Reduced Mo powder is added to the ball mill tank, and ball milling is performed for 2-96h. Step 4: Pour the ball milled material from Step 3 into a stainless steel tray, and then place the tray in a vacuum drying box at 60-120 ° C. Drying; step five, transfer the material obtained after drying in step four into a graphite crucible coated with BN powder on the inner wall, and then place the graphite crucible in a vacuum furnace under the condition that the pressure in the vacuum furnace is controlled to be 0.5-30 GPa. At 0.5-30 ℃ / m.