CN101984110A

CN101984110A - Preparation method of pre-alloy powder of ferrum-aluminum intermetallic compound Fe2Al5

Info

Publication number: CN101984110A
Application number: CN 201010576917
Authority: CN
Inventors: 龙坚战; 魏修宇; 陆必志; 方晴; 余怀民; 李勇; 卢少武; 管玉明; 蒋洪亮
Original assignee: Zhuzhou Cemented Carbide Group Co Ltd
Current assignee: Zhuzhou Cemented Carbide Group Co Ltd
Priority date: 2010-12-07
Filing date: 2010-12-07
Publication date: 2011-03-09
Anticipated expiration: 2030-12-07
Also published as: CN101984110B

Abstract

The invention discloses a preparation method of pre-alloy powder of a ferrum-aluminum intermetallic compound Fe2Al5 with uniform components and fine granularity, which successively comprises the following steps: proportioning ferrum powder and aluminum powder according to the weight percent of Fe2Al5 and obtaining the uniform mixing powder through ball-milling, mixing and sieving; placing the mixing powder into a container to be flattened; heating the mixing powder to the reaction temperature of the main solid phase of ferrum-aluminum to be sintered at the vacuum or non-oxidative atmosphere; naturally cooling when maintaining the temperature for 4 to 8 hours; and grinding and sieving the obtained Fe2Al5 intermetallic pre-alloy to obtain the pre-alloy powder of the ferrum-aluminum intermetallic compound Fe2Al5. The preparation method of the invention has the advantages of simple technology, high efficiency and low cost.

Description

Iron-Al intermetallic Fe 2Al 5The preparation method of pre-alloyed powder

Technical field

Present method belongs to field of powder metallurgy, relates to a kind of preparation method of pre-alloyed powder of iron-Al intermetallic.

Background technology

The characteristic of metallic bond and covalent linkage coexistence between the long-range order arrangement of intermetallic compound atom and atom, make its use temperature and some mechanical property between Ni based high-temperature alloy and high temperature ceramic material, also has unique superiority at resistance to high temperature oxidation, aspect such as anticorrosive, as FeAl, Fe ₃The resistance to corrosion of Al intermetallic compound is strong, and weak ferromagnetism is suitable for bad working environment.The application direction of Fe-Al series intermetallic compound mainly is the structural part as anti-sulfur-bearing atmosphere and resistance to oxidation atmosphere at present.Fe ₃The Al alloy not only has good heat-resisting, wear-resisting and corrosion resistance nature, and its room temperature unit elongation can reach 12.8%, has application potential in various fields such as aviation, chemical industry, nuclear reactor component, smelting furnace high temperature service, electromagnetic components.

Chinese patent (the publication number 101838752A that " utilizes dusty raw materials to make the method for iron aluminum intermetallic compound homogenizing porous material "; open on 09 22nd, 2010 day) a kind of method of utilizing dusty raw materials to make the iron aluminum intermetallic compound homogenizing porous material is disclosed; its key is that the mixed powder to iron powder and aluminium powder has carried out the heat pre-treatment operation before shaping; promptly the mixed powder of iron powder and aluminium powder is being heated to 400-950 ℃ under the anti-oxidation protection atmosphere or under the vacuum; pulverize behind the naturally cooling and mill, its weak point is that its pre-alloyed powder is Fe ₂Al ₅, FeAl ₂, FeAl ₃Mixed powder.

Another Chinese patent " is made the method for iron aluminium or Fe-3 Al metal meta-compound elements " (Granted publication CN1061279C, 01 month 31 days calendar year 2001 of the day for announcing), and this method obtains Fe with pure iron and fine aluminium fusing earlier ₂Al ₅, FeAl ₂, FeAl ₃Compound powder adds straight iron powder and above-mentioned powder mixes more in proportion, and compression moulding at normal temperatures then through liquid phase sintering, can obtain required part, and it adopts intermetallic compound pre-alloyed powder composition is Fe ₂Al ₅, FeAl ₂, FeAl ₃Mixture; It adopts the pre-alloyed powder preparation method who atomizes after the melting, cost height.

Because the combination reaction between the iron aluminium element powder is a kind of thermopositive reaction, in the combination reaction of fierceness, can discharge a large amount of heats, thereby cause temperature of reaction system to raise rapidly, technological process is uncontrollable, so general adopt powder metallurgy technology to prepare intermetallic compound and matrix material all is to adopt pre-alloyed powder to utilize extruding, HIP(hot isostatic pressing with other element powders), technology such as vacuum hotpressing, thermojet make the pre-alloyed powder densification change into intermetallic compound.Required intermetallic compound pre-alloyed powder generally is to adopt the melting obtaining intermetallics, become pre-alloyed powder by rare gas element or vacuum atomizing then, but, adopt the granularity of intermetallic compound pre-alloyed powder of this method preparation thick, in follow-up preparation composite material, in material, form easily " metal pool ", reduced the mechanical property of material.Along with more and more high to the inhomogeneity requirement of the finished product chemical ingredients, it is quite important that the homogeneity of pre-alloyed powder and granularity seem.

Summary of the invention

The object of the present invention is to provide the iron that a kind of composition is even, granularity is tiny-Al intermetallic Fe ₂Al ₅The manufacture method of pre-alloyed powder, and technology is simple, efficient and cost is low.

Iron of the present invention-Al intermetallic Fe ₂Al ₅The preparation method of pre-alloyed powder, may further comprise the steps successively:

(1) iron powder and aluminium powder are pressed Fe ₂Al ₅Mass percent batching, ball milling mixes, sieves, and obtains uniform mixed powder;

(2) place container to pave above-mentioned mixed powder, under vacuum or non-oxidizing atmosphere, be heated to the main solid state reaction temperature of iron-aluminium and carry out sintering, be incubated 4-8 hour, naturally cooling obtains Fe then ₂Al ₅The intermetallic prealloy;

(3) with Fe ₂Al ₅The intermetallic prealloy is milled, is sieved, and obtains iron-Al intermetallic Fe ₂Al ₅Pre-alloyed powder.

As improvement, described iron powder is a carbonyl iron dust, granularity 10 μ m-60 μ m; Aluminium powder is the analytical pure aluminium powder, granularity 50 μ m-100 μ m.

Iron-aluminium solid state reaction temperature is 400 ℃-640 ℃, and main solid state reaction temperature is 550 ℃-640 ℃; Described heating comprises from room temperature to 400 ℃-450 ℃, heats up to two stages of main solid state reaction temperature, and wherein previous stage, heat-up rate was 3 ℃/min-10 ℃/min, the latter half heat-up rate≤2 ℃/min.

Fe ₂Al ₅Intermetallic pre-alloyed powder granularity is≤40 μ m.

As further improvement, container adopts cast iron vessel, and mixed powder places the thickness≤10mm that paves of container.

Because Fe ₂Al ₅Thermomechanical property stable, in iron-aluminium solid state reaction process, generate Fe easily ₂Al ₅, this intermetallic compound fragility is big simultaneously, and the fragmentation of milling easily can access the little pre-alloyed powder of fine size.Preparation method of the present invention makes and fulfils the heat reaction process between iron powder and aluminium powder ahead of schedule, can reduce the hole that produces owing to diffusion in the follow-up preparation inter-metallic compound material process, add the carbonyl iron particles and the analytically pure aluminium powder that adopt activity strong, thereby further guaranteed the even and mechanical property of composition of alloy material.

As further improvement, the present invention has adopted the cast iron vessel of good heat conductivity.This is because iron aluminium solid state reaction obtaining intermetallics belongs to thermopositive reaction, the heat of reaction can impel the temperature of powder to raise, after temperature surpasses the fusing point of aluminium, after aluminium is melt into liquid, in the effect of capillary force and gravity and move, cause the ununiformity of powder composition; And the heat that cast iron vessel produces the solid state reaction of its reaction can pass away rapidly, guarantees that its reaction synthesis temperature is at solid-state temperature.Simultaneously, because the hole between the powder is bigger, heat is difficult for conduction, and the shop of powder is put thickness and is no more than 10mm, has avoided the heat of powder inside to put aside and make the fusing point of solid state reaction temperature above aluminium.

Description of drawings

Fig. 1 is iron-Al intermetallic Fe that the present invention prepares ₂Al ₅The stereoscan photograph of pre-alloyed powder.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention will be further described.

Embodiment 1: with granularity is that the analytical pure aluminium powder of the carbonyl iron dust of 60 μ m and granularity 100 μ m is by Fe ₂Al ₅Mass percent batching, ball milling mixes, crosses 100 mesh sieves, obtains uniform mixed powder; Place cast iron vessel to pave thickness above-mentioned mixed powder, under the vacuum of 1-5Pa, with the speed of 10 ℃/min, be warmed up to 450 ℃ from room temperature to 10mm, speed with 2 ℃/min is heated to 640 ℃ then, be incubated 4 hours and carry out sintering, naturally cooling obtains Fe then ₂Al ₅The intermetallic prealloy; With Fe ₂Al ₅325 mesh sieves are milled, crossed to the intermetallic prealloy, obtains iron-Al intermetallic Fe of granularity≤40 μ m ₂Al ₅Pre-alloyed powder, its typical metallograph is seen Fig. 1 (following examples with).Can see iron-Al intermetallic Fe that the inventive method obtains by Fig. 1 ₂Al ₅The pre-alloyed powder composition even.

Embodiment 2: with granularity is that the aluminium powder of the iron powder of 10 μ m and granularity 50 μ m is by Fe ₂Al ₅Mass percent batching, ball milling mixes, crosses 200 mesh sieves, obtains mixed powder; Place cast iron vessel to pave thickness above-mentioned mixed powder, under hydrogen shield, with the speed of 3 ℃/min, be warmed up to 400 ℃ from room temperature to 6mm; speed with 0.5 ℃/min is heated to 550 ℃ then; be incubated 8 hours and carry out sintering, naturally cooling obtains Fe then ₂Al ₅The intermetallic prealloy; With Fe ₂Al ₅500 mesh sieves are milled, crossed to the intermetallic prealloy, obtains iron-Al intermetallic Fe of granularity≤25 μ m ₂Al ₅Pre-alloyed powder.

Embodiment 3: with granularity is that the iron powder of 30 μ m and granularity 80 μ m analytical pure aluminium powders are by Fe ₂Al ₅Mass percent batching, ball milling mixes, crosses 100 mesh sieves, obtains mixed powder; Place cast iron vessel to pave the thickness to 8mm above-mentioned mixed powder, under argon shield, with the speed of 5 ℃/min, be warmed up to 430 ℃ from room temperature, the speed with 1 ℃/min is heated to 600 ℃ then, is incubated 6 hours and carries out sintering, and naturally cooling obtains Fe then ₂Al ₅The intermetallic prealloy; With Fe ₂Al ₅425 mesh sieves are milled, crossed to the intermetallic prealloy, obtains iron-Al intermetallic Fe of granularity≤33 μ m ₂Al ₅Pre-alloyed powder.

Embodiment 4: with granularity is that carbonyl iron dust and the granularity of 40 μ m is that 70 μ m aluminium powders are by Fe ₂Al ₅Mass percent batching, ball milling mixes, crosses 100 eye mesh screens, obtains mixed powder; Place cast iron vessel to pave the thickness to 8mm above-mentioned mixed powder, under protection of nitrogen gas, with the speed of 5 ℃/min, be warmed up to 430 ℃ from room temperature, the speed with 1 ℃/min is heated to 600 ℃ of temperature then, is incubated 6 hours and carries out sintering, and cooling then obtains Fe ₂Al ₅The intermetallic prealloy; With Fe ₂Al ₅425 eye mesh screens are milled, crossed to the intermetallic prealloy, obtains iron-Al intermetallic Fe of granularity≤33 μ m ₂Al ₅Pre-alloyed powder.

Iron-Al intermetallic the Fe of the present invention's preparation ₂Al ₅The pre-alloyed powder composition even, granularity≤40 μ m, and technology is simple, efficient is high, cost is low.

Claims

1. iron-Al intermetallic Fe ₂Al ₅The preparation method of pre-alloyed powder, it is characterized in that this method may further comprise the steps successively: (1) presses Fe with iron powder and aluminium powder ₂Al ₅Mass percent batching, ball milling mixes, sieves, and obtains uniform mixed powder; (2) place container to pave above-mentioned mixed powder, under vacuum or non-oxidizing atmosphere, be heated to the main solid state reaction temperature of iron-aluminium and carry out sintering, be incubated 4-8 hour, naturally cooling obtains Fe then ₂Al ₅The intermetallic prealloy; (3) with Fe ₂Al ₅The intermetallic prealloy is milled, is sieved, and obtains iron-Al intermetallic Fe ₂Al ₅Pre-alloyed powder.

2. iron as claimed in claim 1-Al intermetallic Fe ₂Al ₅The preparation method of pre-alloyed powder, it is characterized in that: described iron powder is a carbonyl iron dust, granularity 10 μ m-60 μ m; Aluminium powder is the analytical pure aluminium powder, granularity 50 μ m-100 μ m.

3. iron as claimed in claim 1-Al intermetallic Fe ₂Al ₅The preparation method of pre-alloyed powder, it is characterized in that: described iron-aluminium solid state reaction temperature is 400 ℃-640 ℃, main solid state reaction temperature is 550 ℃-640 ℃; Described heating comprises from room temperature to 400 ℃-450 ℃, heats up to two stages of main solid state reaction temperature, and wherein previous stage, heat-up rate was 3 ℃/min-10 ℃/min, the latter half heat-up rate≤2 ℃/min.

4. iron as claimed in claim 1-Al intermetallic Fe ₂Al ₅The preparation method of pre-alloyed powder, it is characterized in that: described Fe ₂Al ₅Intermetallic pre-alloyed powder granularity is≤40 μ m.

5. iron as claimed in claim 1-Al intermetallic Fe ₂Al ₅The preparation method of pre-alloyed powder, it is characterized in that: described container is a cast iron vessel, mixed powder places the thickness≤10mm that paves of container.