A kind of method that adopts high-energy ball milling to prepare aluminum oxide dispersion strengthened iron pre-alloyed powderTechnical field
The invention belongs to oxide dispersion intensifying (Oxide Dispersion Strengthened, ODS) pre-alloyed powder preparing technical field provides a kind of method that adopts high-energy ball milling oxide and iron oxide mixed-powder to prepare aluminum oxide dispersion strengthened iron pre-alloyed powder especially.
Technical background
The fast breeder generating is the important development direction of following nuclear energy uses, and the fuel canning material of the low swelling low-activity of anti-irradiation is the important technological problems that fast reactor practicability must solve.The general fast reactor cladding materials of world the countries concerned is 316 austenitic stainless steels at present, and its swelling rate is higher, does not possess the long-life requirement.Ferritic steel has good anti-swelling, but elevated temperature strength is relatively poor, has also limited its service life.And ODS (Oxide dispersion strengthened) type ferritic steel can increase substantially elevated temperature strength, has good anti-swelling performance again, is the preliminary election material that the fuel canning material long lifetime gets a good chance of.Powder metallurgical technique is mainly all adopted in the preparation of ODS ferritic steel at present, and wherein main component is oxide dispersion intensifying iron, and the preparation research of therefore carrying out oxide dispersion intensifying iron is very important.
The dispersion-strengtherning technology is highly effective means to heat endurance and hardness, the intensity that improves high temperature alloy particularly, also is the good method that common metal improves high-temperature behavior and mechanical property.The stable performance at high temperature of dispersed oxide phase particle, these disperses are distributed in creep resisting ability and the elevated temperature strength that resistance that the oxide particle in the matrix moves as dislocation can effectively improve alloy, in addition, disperse is distributed in the carrying out that oxide particle in the matrix can hinder recrystallization process, obtains stable crystallite dimension easily.It is generally acknowledged that oxide particle is more tiny, it is more even to distribute, and the raising of material property is just more remarkable.Oxide dispersion intensifying is existing extremely successful application example in fields such as high property copper alloy, high temperature alloys.
At present, main mechanical alloying, the methods such as interior oxidation of adopting in the preparation of Oxide Dispersion Strengthened Materials Made.The method that Chinese invention patent: CN200610128421.8 discloses a kind of interior oxidation prepares Al2O3Dispersion strengthening copper alloy materials.The method that Chinese invention patent: CN94112582.3 discloses a kind of mechanical ball milling alloying prepares the dispersion-strengthened copper electrode for upset welding material.Document 1 (material engineering, 1995,4:6) reported, take Fe as starting powder, with Cr, Al, Ti, Mo is the intermediate alloy powder, with Y2O3(d＜50nm) be the second-phase dispersion enhanced particles to prepare high temperature alloy by the mechanical alloy metallization processes.Chinese invention patent: CN101535674A discloses the method that a kind of high-energy ball milling prepares oxide dispersion strengthened austenitic stainless steel.In its mechanical milling process, disperse phase and metal dust mix, but because metal dust is harder, short time inner oxide disperse phase can not be wrapped up by metal dust, can take place to reunite in the dispersed oxide phase powder process afterwards that is not wrapped to grow up, and then worsen the performance of material.
Summary of the invention
The object of the present invention is to provide a kind of method of utilizing high-energy ball milling to prepare the method for aluminum oxide dispersion strengthened iron pre-alloyed powder, solve in traditional mechanical alloying mechanical milling process, because metal dust is harder, short time inner oxide disperse phase can not be wrapped up by metal dust, can take place to reunite in the dispersed oxide phase powder process afterwards that is not wrapped to grow up, and then worsen the problem of the performance of material.
A kind ofly prepare the method for oxide dispersion intensifying iron pre-alloyed powder with high-energy ball milling, its technical process is: take by weighing a certain amount of Fe2O3Powder and disperse phase oxide powder, the oxide powder that takes by weighing will guarantee that its content in iron-oxide system is 1-3%, to guarantee dispersion-strengthened effect.Iron-oxide mixed-powder is put into the planetary high-energy ball mill ball milling, and ratio of grinding media to material is 10-12: 1, and drum's speed of rotation is 350-400r/min, the ball milling time is 20-40 hour, does not comprise downtime.Every ball milling was shut down 1 hour in 5 hours, and is too high to prevent the ball grinder temperature.Then the powder that ball milling is good in hydrogen stream at 700-900 ℃ of reduction 40-60min, because Fe2O3Can be by hydrogen reducing and the disperse phase oxide can not, therefore obtain at last the oxide dispersion intensifying iron pre-alloyed powder.
This method is compared with traditional mechanical alloying, adopts Fe2O3Powder replaces metal iron powder end and the common ball milling of dispersed oxide phase powder with the common ball milling of disperse phase oxide powder, because Fe2O3Powder is softer than Fe powder, so in the process of high-energy ball milling, the easier Fe that enters into of disperse phase2O3In the powder and then by Fe2O3Powder wraps up, and resulting disperse phase distributes more even, and the disperse phase oxide powder that is wrapped can not reunited with other disperse phase oxide powder in mechanical milling process, has suppressed growing up of disperse phase, and resulting disperse phase particle is tiny.
The specific embodiment
Embodiment 1:1%Al2O3The dispersion strengthened iron powder
Testing used raw material is Fe2O3Powder and Al2O3Powder uses the purity of powder all greater than 99.9%, wherein Fe2O3The granularity of powder is 10 μ m, Al2O3The granularity of powder is 30nm.Take by weighing a certain amount of Fe2O3Powder and Al2O3Powder guarantees Al2O3At Fe-Al2O3Content in the system is 1%.Mixed-powder is put into the planetary high-energy ball mill ball milling, and ratio of grinding media to material is 10: 1, and the rotating speed of ball mill is 350r/min, and the ball milling time was controlled at 40 hours, did not comprise downtime.Every ball milling was shut down 1 hour in 5 hours, and is too high to prevent the ball grinder temperature.The powder that ball milling is good at 700 ℃ of reduction 60min, obtains Al at last in hydrogen stream then2O3Dispersion strengthened iron pre-alloyed powder.
Embodiment 2:2%Al2O3The dispersion strengthened iron powder
Testing used raw material is Fe2O3Powder and Al2O3Powder uses the purity of powder all greater than 99.9%, wherein Fe2O3The granularity of powder is 10 μ m, Al2O3The granularity of powder is 30nm.Take by weighing a certain amount of Fe2O3Powder and Al2O3Powder guarantees Al2O3At Fe-Al2O3Content in the system is 2%.Mixed-powder is put into the planetary high-energy ball mill ball milling, and ratio of grinding media to material is 11: 1, and the rotating speed of ball mill is 380r/min, and the ball milling time was controlled at 30 hours, did not comprise downtime.Every ball milling was shut down 1 hour in 5 hours, and is too high to prevent the ball grinder temperature.The powder that ball milling is good at 800 ℃ of reduction 50min, obtains Al at last in hydrogen stream then2O3Dispersion strengthened iron pre-alloyed powder.
Embodiment 3:3%Y2O3The dispersion strengthened iron powder
Testing used raw material is Fe2O3Powder and Y2O3Powder uses the purity of powder all greater than 99.9%, wherein Fe2O3The granularity of powder is 10 μ m, Y2O3The granularity of powder is 30nm.Take by weighing a certain amount of Fe2O3Powder and Y2O3Powder guarantees Y2O3At Fe-Y2O3Content in the system is 3%.Mixed-powder is put into the planetary high-energy ball mill ball milling, and ratio of grinding media to material is 12: 1, and the rotating speed of ball mill is 400r/min, and the ball milling time was controlled at 20 hours, did not comprise downtime.Every ball milling was shut down 1 hour in 5 hours, and is too high to prevent the ball grinder temperature.The powder that ball milling is good at 900 ℃ of reduction 40min, obtains Y at last in hydrogen stream then2O3Dispersion strengthened iron pre-alloyed powder.