CN1058233A - The manufacture method that contains the Wimet of rare earth - Google Patents

Abstract

The present invention proposes a kind of manufacture method that contains the Wimet of rare earth.The rare earth that employing is produced with alloying-cobalt-base alloy powder is to make the Wimet that contains rare earth after raw material and other powder stock batching.With the alloy that method of the present invention is made,, therefore can give full play to the effect of rare earth element because the rare earth element in the alloy is evenly distributed mutually with＜0.5 micron spherical rare earth.Compare with other addition manner, can under the condition that does not change the alloy original production process substantially, obviously improve alloy property, and different stove, batch stable, the good reproducibility of product performance.

Description

The manufacture method that contains the Wimet of rare earth

The present invention relates to the wolfram varbide be the manufacture method of Wimet of base, especially relevant with the manufacture method of the Wimet that contains rare earth.

Cutting tool, mould, boring tool and other wear-resisting, the shock-resistant parts made of the Wimet with excellent over-all properties are that institutes of all departments such as machinery, electronics, chemical industry, oil, geology are indispensable, add the Wimet of rare earth element and then pay close attention to owing to the toughness of having improved alloy, oxidation-resistance, shock resistance and hot strength cause people.The Wimet that contains rare earth generally all adopts powder metallurgical technique, promptly prepares powder stock, composition batching, coldmoulding after grinding, mixing, drying on demand, makes the Wimet of desired shape again through sintering.DE3228692, spy open clear 59-43840, and the spy opens clear 61-183439, disclose the addition manner of several alloy middle-weight rare earths elements in CN 89105708 documents.They are with rare earth metal powder, RE oxide powder, nitride powder as raw material directly and powder mixes such as carbide be mixed with Wimet.The Wimet that uses these interpolation rare earth element modes to make improves the performance of alloy to some extent with the specific energy mutually of not adding rare earth element, but has the following disadvantages.(1) alloy property instability, this is tighter to the alloy manufacture process requirement owing to adding rare earth element in this class mode, otherwise the rare earth in the alloy is many with bulk, the form of thicker rare earth phase such as cerioid exists, thick rare earth becomes in alloy and is mingled with, can offset the good action of rare earth element, cause the product performance instability.(2) to different components system (mainly contain WC-Co, WC-TiC-Co is with WC-TiC-TaC(NbC)-series such as Co), the Wimet of the different trade mark, different rare earth kind and addition must seek best fabrication process parameters by test.Owing to there are these deficiencies, the mass production that has limited carbide alloy of rare earth is with widely-used.

The objective of the invention is to propose a kind of manufacture method of carbide alloy of rare earth, this method highly versatile can obviously improve alloy property under the condition that does not change former alloy manufacturing process substantially.

The manufacture method of the carbide alloy of rare earth that the present invention proposes comprises that mainly preparing the powder operation, coldmoulding, the sintering that contain rare earth makes carbide alloy of rare earth.Wherein make the powder operation that contains rare earth and be meant that preparation contains cobalt powder (also can contain other iron family element tings) operation of rare earth.The cobalt powder that contains rare earth can be the mechanically mixing powder, also can be the powder that contains rare earth with the wet method prepared by co-precipitation, also can be alloy powder.The present invention prepares the melting technology that the alloy powder operation adopts general alloy, be to be raw material with cobalt metal and rare earth metal, press the proportion ingredient of 10-40 weight % rare earth-cobalt, after at least twice melting under argon gas or the vacuum, obtain the intermetallic compound of rare earth-cobalt, through broken, grind, sieving obtains rare earth-cobalt master alloy powder.Also other iron family element tings can be arranged in the cobalt metal, as nickel, iron etc.From the phasor of each rare earth element and cobalt as can be known, there are various intermetallic compounds in rare earth element and cobalt in big composition scope (10-40%), and these compound hardness are high and crisp, are broken into fritter easily and grind to form superfine powder.Therefore the rare-earths-cobalt of preparing in this composition scope just is easy to make the cobalt powder that contains rare earth.The alloy fragmentation easily that content of rare earth is higher, but content of rare earth is higher, the alloy powder amount that joins in the Wimet is just more lacked, and can influence the homogeneity that Wimet middle-weight rare earths element distributes, and therefore content of rare earth is no more than 40 weight % generally speaking.For obtaining composition rare earth-cobalt master alloy uniformly, need melting twice at least, melting number of times many gained alloy more is even more, but the rare earth loss is also bigger.

According to the composition requirement,, also can add cobalt powder in case of necessity with carbide powder and rare-earths-cobalt powder weighing and burden.In process of lapping, various powder thorough mixing.Blended powder material can not change this composition system substantially, makes the Wimet that contains rare earth that performance is significantly improved under the condition of the former manufacturing process of this trade mark Wimet.

Adopt the manufacture method of the Wimet that contains rare earth of the present invention's proposition to produce the bending strength that Wimet can obviously improve alloy.Because rare earth element can be evenly distributed in the alloy with＜0.5 micron spherical rare earth form utmost point mutually mutually in cobalt binder with solid solution, thus the bending strength value of each heat, Wimet that each is produced in batches fluctuate minimum, steady quality.Test shows, adopt Wimet manufacture method of the present invention, Wimet to different components system, the different trades mark adds different rare earth elements, as Ce, Y, La, Sm, Pr, Nd or based on mishmetal of Ce or Y etc., can not change the processing parameter of former alloy basically and obtain the Wimet that performance is significantly improved.

Further specify embodiments of the present invention and positively effect thereof with following indefiniteness embodiment.(percentage composition all is weight percentage in the example)

1. adopting rare earth cerium (Ce) metal block and cobalt metal plate is raw material, and respectively by 10,15,25,30,40%Ce prepares burden, and puts into the crucible of tungsten electrode non-consumable arc furnace respectively, melting for the first time under argon shield, and the ingot casting that obtains is secondary smelting in stove again.Alloy material after the melting is put into the Wimet ball grinding cylinder after being broken into fritter, grinds 24 hours in the alcohol medium, crosses 320 mesh sieves, promptly obtains containing the cerium-cobalt master alloyed powder of different cerium contents after the oven dry.Rare earth element after the melting in the alloy has scaling loss in various degree.

2. adopting rare earth (yttrium, samarium, lanthanum, neodymium, praseodymium, cerium+yttrium) metal block and cobalt metal plate is raw material, is 10,15,25,30 by the % of rare earth metal, the yttrium-cobalt of the different content of rare earth of 40 preparations, samarium-cobalt, lanthanum-cobalt, neodymium-cobalt, praseodymium-cobalt, cerium+yttrium-cobalt master alloy.Alloy powder preparation technology is identical with example one, and difference is melting in vacuum oven.

3. adopt rare earth (cerium, lanthanum, samarium, yttrium)-cobalt master alloyed powder and the commercially available WC powder that makes in example one and the example two, the Co powder is a raw material, press WC-6%Co-0.04% rare earth and WC-6%Co batch mixes, press the former technology of WC-6% alloy, promptly 36 hours after drying of ball milling are sneaked into 2% wax moulding agent, coldmoulding, remove paraffin in 550 ℃ again in hydrogen, 1400 ± 10 ℃ of sintering 1 hour under vacuum promptly make five kinds of Wimet then.Its performance sees Table 1.

Table 1

Rare earth element in the alloy	Bending strength MPa	Hardness HRA
			No cerium lanthanum samarium yttrium	1571 1738 1715 1810 1930	89.5 89.5 89.8 90.0 90.5

4. adopt rare earth (neodymium, yttrium, cerium)-cobalt master alloyed powder and the commercially available (Ti that makes in example one and the example two, W) C powder, the Co powder is a raw material, press WC-14%TiC-8%Co-0.08% rare earth and WC-14%TiC-8%Co batch mixes, press the former technology of alloy, promptly with example three essentially identical technologies, difference is ball milling 72 hours, and sintering temperature is 1460 ± 10 ℃.Four kinds of Wimet performances that make see Table 2.

Table 2

Rare earth element in the alloy	Bending strength MPa	Hardness HRA
			No neodymium yttrium cerium	1476 1665 1608 1580	91.0 91.4 91.2 91.0

5. adopting rare earth (praseodymium, neodymium, yttrium+cerium)-cobalt master alloyed powder and commercially available (Ti.W) C powder, Co powder and the TaC powder that make in example one and the example two is raw material, after pressing WC-6% TiC-3% TaC-8% Co-0.12% rare earth and WC-6% TiC-3% TaC-8% Co batch mixes, adopt the alloy preparation technology of example three, wherein sintering temperature is 1460 ± 10 ℃, and the performance that makes four kinds of Wimet sees Table 3.

Table 3

Rare earth element in the alloy	Bending strength MPa	Hardness HRA
			No praseodymium neodymium cerium+yttrium	1531 1812 1848 1925	90.5 91.0 90.8 91.0

6. adopt the metallic yttrium powder respectively, the rare earths material of yttrium oxide powder and 15 weight % yttrium-cobalt master alloyed powders and commercially available WC powder and Co are raw material, be weight % by WC-8%Co-0.04%Y and WC-8%Co() the proportioning mixing, adopt the alloy preparation technology of example three, wherein sintering temperature is 1400 ± 10 ℃, and the bending strength value of four kinds of Wimet is listed in table 4.Can find out from table 4 to add the Wimet of rare earth element with yttrium-cobalt-base alloy powder form not only the bending strength increase rate is bigger, and also little than other modes of its performance inconsistency amplitude.

Table 4

Performance	Heat	The rare earth addition manner
						The yttrium oxide powder	The metallic yttrium powder	Cobalt-yittrium alloy powder	Do not add
		Bending strength MPa	1 2 3 4 5	2211 2306 2452 2668 2660	2003 2479 2635 2346 2671					2466 2664 2488 2537 2481	2206 2277 2369 2239 2214
On average	2459					2427	2527	2261
			Raising rate %	8.7	7.3				11.8	----

Annotate: data are the mean value of 10 samples in the table

Rare-earth morphology in the scanning electron microscope transmission electron microscope observing alloy shows, in with the Wimet that yttrium-cobalt-base alloy powder form adding rare earth element is made, rare earth element remove cobalt binder mutually in micro-solid solution, change outside its phase structure, all exist mutually, with then manyly existing mutually that yttrium oxide powder or metallic yttrium powder form add with block, the thicker rare earth of cerioid with＜0.5 micron spherical rare earth.Thick rare earth becomes in alloy and is mingled with, and has offset the good action of rare earth.And this rare earth is bonding poor with Co, easily peels off, thereby cause the product performance instability.

7. four kinds of alloys making of use-case six are made each three on the blade of 31303C model respectively, and general foundry goods is carried out turning test, 81.4 meters/minute of cutting speeds, 5 millimeters of cutting outputs.The alloy cutter that does not contain rare earth bad point of a knife phenomenon promptly occurs after processing 15,17,11.Add the alloy cutter of rare earth element with metallic yttrium powder and yttrium oxide powder mode, bad point of a knife phenomenon occurs after processing 15,25,18 and 10,16,23.And bad point of a knife phenomenon does not appear with after 27 of alloy cutter that yttrium-cobalt master alloyed powder mode the adds processing.

To carrying out the shock resistance test with the metallic yttrium powder with two kinds of blades that yttrium-cobalt master alloy mode adds rare earth.Machined material is the 38CrNi3MoVA Steel Bar During, axially opens four wide grooves of 15 millimeters along bar, and cutting speed is 95 meters of per minutes, and the bar blade that whenever circles is hit four times.As a result, tipping promptly occurs after the blade that adds rare earth with the metallic yttrium powder impacts 72 times, and the blade that adds rare earth in yttrium-cobalt master alloy mode has only the wearing and tearing of blade after impacting 171 times, and tipping do not occur.

Claims (2)

1, a kind of manufacture method of carbide alloy of rare earth comprises:

[1] preparation rare-earths-cobalt powder,

[2] grinding and mixed processes, it is that carbide powder and the cobalt powder that contains rare earth are ground and mixing,

[3] compression moulding operation,

[4] sintering circuit.

2, by the manufacture method of a kind of carbide alloy of rare earth of claim 1, to it is characterized in that preparing rare-earths-cobalt powder operation be batching, at least twice melting, fragmentation, grind, sieve, and wherein the content of rare earth element is 10-40 weight %.