CN105728733A - A method for preparing nanometer Co-CeO2 composite powder by mechanical alloying - Google Patents

Abstract

The invention discloses a method for preparing nanometer Co?CeO ₂ composite powder by mechanical alloying. It prepares Co powder and CeO ₂ powder according to the mass ratio of 10:0.4, and adds 20 to 40 times the total mass of the powder. Carbide balls and 1-3% of the total mass of powder are volatile organic solvents as ball milling media, and ball milled in a cemented carbide ball mill tank with atmosphere protection or vacuum conditions for 12-36 hours. After ball milling, statically Leave it for a period of time, and take out the powder in the glove box after fully cooling to obtain evenly distributed nano-Co?CeO ₂ composite powder. The invention has the characteristics of uniform rare earth _oxide distribution and simple preparation process, and obtains nanometer Co?CeO2 composite powder with good quality and performance and low production cost.

Description

A method for preparing nanometer Co-CeO2 composite powder by mechanical alloying

technical field

The invention belongs to the technical field of nanocomposite powder preparation, and in particular relates to a method for preparing nanometer Co _- CeO2 composite powder by mechanical alloying.

Background technique

WC-Co cemented carbide is widely used in metal cutting tools, micro-engraving tools (bars), electronics industry (such as micro-drilling) due to its excellent properties such as high wear resistance, high hardness, high strength, and high red hardness. , Woodworking tools and other fields. Studies have shown that the addition of rare earth oxides can improve the performance of WC-Co cemented carbide: First, the rare earth oxides will be distributed on the grain boundaries, effectively preventing the migration of grain boundaries and the dissolution of WC in Co, thereby inhibiting the formation of grain boundaries. Aggregation and growth; second, it can purify the impurities in the grain boundary, which not only plays a role in dispersion strengthening of the binder phase, but also reduces the sintering temperature of the cemented carbide. Therefore, this method has received more and more attention. At present, the preparation method of uniformly mixing WC powder, Co powder and rare earth oxides by mechanical mixing is generally used. The defect of this method is: due to the small amount of rare earth oxides added, the It is difficult to mix evenly with WC powder and Co powder, so that the distribution of rare earth oxides is uneven, and the phenomenon of local grain aggregation and growth will occur during the sintering process, which will reduce the quality and performance of the product. CN201410184144.7 discloses a "preparation method of WC-rare earth-Co layer-by-layer coated cemented carbide composite powder", which first uses a chemical activation solution to perform ultrasonic activation pretreatment on WC powder at room temperature, and then places rare earth In the oxide suspension, after ultrasonic stirring for a certain period of time, the WC composite powder coated with rare earth oxide is obtained, and then the WC-rare earth-Co coated cemented carbide composite powder is obtained by electroless cobalt plating. However, the process of this method is complicated, and impurities are likely to remain in the process.

Contents of the invention

The object of the present invention is to provide a method for preparing nano-Co _- CeO2 composite powder by mechanical alloying with uniform rare earth oxide distribution and simple preparation process, so as to obtain nano-Co _- CeO2 composite powder with good quality and performance and low production cost.

In order to achieve the above object, a kind of mechanical alloying of the present invention is used to prepare nanometer Co-CeO _The operation steps of the method for composite powder are as follows:

Step a: Prepare Co powder and CeO powder according to the mass ratio of ₁₀ :0.4, and put them into a ball mill jar;

Step b: In the ball mill tank, add 1-3% of the total mass of the powder as a volatile organic solvent as a ball milling medium and cemented carbide grinding balls 20-40 times the total mass of the powder;

Step c: Carry out atmosphere treatment in the ball mill tank, start ball milling, the ball milling time is 12-36 hours, stand still after the ball milling is completed, take out the powder in the glove box after the powder and balls are fully cooled, and obtain evenly distributed nano Co _-CeO2 composite powder.

The volatile organic solvent is absolute ethanol.

The atmosphere treatment is to fill the ball mill jar with inert gas.

The inert gas is one or a mixture of nitrogen or argon.

The atmosphere treatment is to vacuumize in a ball mill jar.

The Fischer particle size of the Co powder is 1 μm.

The purity of the CeO ₂ powder is greater than 99.99%.

The cemented carbide grinding balls are cemented carbide balls of different sizes and proportions.

The ball mill jar is made of hard alloy.

A kind of method of preparing nanometer Co _- CeO composite powder with mechanical alloying of the present invention has the following characteristics:

1. The ball milling medium is anhydrous ethanol to prevent "cold welding" phenomenon during mechanical alloying.

2. The grinding balls are cemented carbide balls of different sizes and proportions to improve the composite effect of mechanical alloying.

3. The ball milling pot is made of hard alloy to reduce the pollution of the ball milling pot to the powder during the mechanical alloying process.

4. The protective gas filled in the ball mill tank is nitrogen or argon to avoid oxidation of the powder during the mechanical alloying process.

The above-mentioned method for preparing nano-Co-CeO ₂ composite powder by mechanical alloying can obtain evenly distributed nano-Co-CeO ₂ composite powder, which has the advantages of stable and good product quality and low production cost.

detailed description

A method for preparing nanometer Co-CeO ₂ composite powder by mechanical alloying of the present invention will be further described in detail below in combination with specific embodiments.

A method of preparing nano-Co _- CeO2 composite powder by mechanical alloying in the present invention. The specific operation steps are as follows: Co powder and CeO2 powder are prepared according to the ratio of mass ratio ₁₀ :0.4, and put into a cemented carbide ball milling tank , add absolute ethanol with 1-3% of the total mass of the powder and cemented carbide balls 20-40 times the total mass of the powder in the ball mill tank, and ball mill for 12-36 hours under the protection of an inert gas atmosphere or vacuum. Hours, after the ball milling, let it stand still, and after the powder and cemented carbide grinding balls are fully cooled, take out the powder in the glove box to obtain evenly distributed nanometer Co-CeO ₂ composite powder.

List the following three embodiments according to different parameters, wherein embodiment 2 is the best embodiment.

Example 1: Co powder and CeO ₂ powder were prepared in a mass ratio of 10:0.4, and put into a cemented carbide ball mill jar. In the cemented carbide ball milling tank, add ball milling medium of 1% of the total mass of the powder and 40 times the amount of cemented carbide balls. Under the protection of nitrogen, ball mill for 12 hours. After the balls were fully cooled, the powder was taken out in the glove box to obtain a uniformly distributed nano-Co _- CeO composite powder.

Example 2: Prepare Co powder and CeO ₂ powder according to the mass ratio of 10:0.4, and put them into a cemented carbide ball mill jar. In the cemented carbide ball milling tank, add ball milling medium of 2% of the total mass of the powder and 30 times the amount of cemented carbide balls. Under the protection of argon, ball mill for 24 hours. After the alloy grinding balls were fully cooled, the powder was taken out in the glove box to obtain evenly distributed nano-Co _- CeO composite powder.

Example 3: Prepare Co powder and CeO ₂ powder according to the mass ratio of 10:0.4, and put them into a cemented carbide ball mill jar. In the cemented carbide ball milling tank, add ball milling medium of 3% of the total mass of the powder and 20 times the amount of cemented carbide balls. Under vacuum conditions, ball mill for 36 hours. After the balls were fully cooled, the powder was taken out in the glove box to obtain a uniformly distributed nano-Co _- CeO composite powder.

Claims (9)

1. prepare nano Co-CeO with mechanical alloying for one kind₂The method of composite powder, is characterized in that: operating procedure is as follows:

Step a: by Co powder and CeO₂The proportions of powder 10:0.4 in mass ratio, puts in ball grinder；

Step b: in ball grinder, the volatile organic solvent of the 1-3% adding powder body gross mass makees ball-milling medium and powder body is total The hard alloy abrading-ball of 20-40 times of quality；

Step c: carry out atmosphere process in ball grinder, starts ball milling, and Ball-milling Time is 12-36 hour, and ball milling stands after terminating, In glove box, powder is taken out, it is thus achieved that equally distributed nano Co-CeO after powder and abrading-ball are sufficiently cool₂Composite powder.

2. nano Co-CeO is prepared in one mechanical alloying as claimed in claim 1₂The method of composite powder, is characterized in that: described Volatile organic solvent is dehydrated alcohol.

3. nano Co-CeO is prepared in one mechanical alloying as claimed in claim 1₂The method of composite powder, is characterized in that: described It is to be filled with noble gas in ball grinder that atmosphere processes.

4. nano Co-CeO is prepared in one mechanical alloying as claimed in claim 1₂The method of composite powder, is characterized in that: described Noble gas is the one in nitrogen or argon or both mixed gas.

5. nano Co-CeO is prepared in one mechanical alloying as claimed in claim 1₂The method of composite powder, is characterized in that: described It is evacuation in ball grinder that atmosphere processes.

6. nano Co-CeO is prepared in one mechanical alloying as claimed in claim 1₂The method of composite powder, is characterized in that: described The Fisher particle size of Co powder is 1 μm.

7. nano Co-CeO is prepared in one mechanical alloying as claimed in claim 1₂The method of composite powder, is characterized in that: described CeO₂The purity of powder is more than 99.99%.

8. nano Co-CeO is prepared in one mechanical alloying as claimed in claim 1₂The method of composite powder, is characterized in that: described Hard alloy abrading-ball is the sintered carbide ball of different size and ratio.

9. nano Co-CeO is prepared in one mechanical alloying as claimed in claim 1₂The method of composite powder, is characterized in that: described Ball grinder uses hard alloy material.