JPH01116008A - Method for compacting metal powder - Google Patents

Abstract

PURPOSE:To obtain a metallic material which has the perfect theoretical density ratio and excellent mechanical properties without having cracks by packing metal powder under specific conditions into a metallic container formed to a prescribed shape and fitting and fixing the container to a metallic frame after hermetic sealing, then subjecting the container to hot pressing to pushing the part projecting from the above-mentioned frame into the frame. CONSTITUTION:The metallic container 2 is formed to such a shape that the sectional shape of the part 2a to be housed in the metallic frame 1 is square, rectangular or trapezoidal and the sectional shape of the part 2b projecting from the frame 1 is trapezoidal, approximately trapezoidal or sectorial. The metal powder of a Co alloy or the like having a prescribed compsn. is packed into such metallic container in a manner as to satisfy the conditional equation and thereafter, the container is hermetically vacuum-sealed. This container is fitted into the polygonal or circular metallic frame 1 and is fixed by welding; thereafter, the container is hot-pressed under adequate conditions, by which the above-mentioned part 2b is pushed into the frame 1 and the above-mentioned powder is compacted. The metallic material which has no possibility of cracking, has 100% theoretical density ratio and exhibits the mechanical properties equiv. or superior to the mechanical properties of the metallic material produced by hot forging from a molten material is thereby obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a metal material having a theoretical density ratio of 100% from metal powder.

[Conventional technology]

Conventionally, metal powder is filled in a metal container under vacuum and sealed, and then the metal container filled with metal powder is hot pressed to form a metal material with a theoretical density ratio of almost 100% into metal powder. Attempts have been made to manufacture it from

[Problem that the invention seeks to solve]

However, with the above-mentioned conventional method, it is difficult to obtain a high-density metal material, and at most it is possible to produce a metal material with a theoretical density ratio of up to 95. Density metal materials cannot be put to practical use. Furthermore, when attempting to obtain a high-density metal material, the metal container would be destroyed, posing a practical problem.

[Means for solving problems]

Therefore, the inventors of the present invention, etc., from the above-mentioned viewpoint.

Easier than hot pressing metal powder
The result of research aimed at producing a metal material with a theoretical density ratio of

A metal container that is fitted into and fixed to a polygonal or circular metal frame is composed of a portion that fits within the metal frame and a portion that protrudes from the metal frame, and a cross section of the portion that fits within the metal frame. The shape is a square, rectangle, or trapezoid, and the cross-sectional shape of the part protruding from the metal frame is trapezoid, approximately trapezoid, or approximately fan shape, and the volume of the part protruding from the metal frame is 1. When the volume of the part that fits into the metal frame is v2.

Conditional expression: V, / V2- (l CIR) / C
In this case, it should be filled under conditions that satisfy AR (where R: filling rate of metal powder, α: correction coefficient) and vacuum-sealed.

If necessary, it is best to heat the metal frame to a temperature of 600C or less to facilitate degassing), then heat the metal frame and metal container, and press the part protruding from the metal frame into the metal frame. When the metal powder protruding from the metal frame is just pushed into the metal frame, the metal material surrounded by the metal frame has a theoretical density ratio of 100-.

In addition, we have obtained the knowledge that it is possible to produce metal materials from molten material that have properties equal to or better than those produced by hot forging without the occurrence of cracks.

This invention was made based on the above findings.

Metal powder is filled into a metal container in which the cross-sectional shape of the part that fits inside the metal frame is square, rectangular, or trapezoid, and the cross-sectional shape of the part that protrudes from the metal frame is trapezoidal, approximately trapezoidal, or approximately fan-shaped, and the metal powder is vacuum-sealed. After.

Fits and secures into a polygonal or circular metal frame.

in this case.

Conditional expression”, Vl / V2 = (1(!R) /
CLR (V: Volume of the part protruding from the metal frame.

v2: Volume of the part that fits into the metal frame, R: Filling rate of metal powder, α: Correction coefficient).

Satisfied.

The method is characterized in that the metal powder is then solidified by heating the metal frame and the metal container and pressing the portion protruding from the metal frame into the metal frame using a press.

Note that the above conditional expression in the method of this invention is as follows.

As shown above, this shows the relationship between the shape of the metal frame and metal container and the filling rate of the metal powder filled into the metal container (this filling rate is a nearly constant value for each metal powder). Therefore, when the part of the metal container protruding from the metal frame is pressed into the metal frame using a press, the nine metal materials bordered by the metal frame have a theoretical density ratio of 100-.

〔Example〕

Next, the method of the present invention will be specifically explained using examples.

As a metal frame, as shown in the schematic perspective view in Figure @1,
It has a rectangular shape and the outer dimensions are width: 150m x length: 24
0XII, inner dimensions width: 1lOoaX length: 2001u
Prepare a mild steel metal frame l with a height of 32111 mm.

Also, as shown in the perspective view in FIG. 2, the metal container includes a portion 2a that fits within the metal frame l, a portion 2b that protrudes from the metal frame, and a portion 2b that protrudes from the metal frame.
The top surface of the metal frame has dimensions of 80 m x vertical = 1 ft. Therefore, the cross-sectional shape of the portion 2a that fits within the metal frame is rectangular.
The cross-sectional shape of the portion 2'b protruding from the metal frame is trapezoidal), and this metal container 2 has a thickness of 2U on the outside with a layer of BN powder applied to facilitate peeling after pressing. It has a double structure made of stainless steel plate, and the inner side is made of mild steel with a thickness of 21 ul.

Furthermore, as metal powder, 1 weight each.

Contains Cr: 28S, W: 4%, C: 1%, with the remainder being C.
CO alloy powder having a composition consisting of o and inevitable impurities.

Cr 2 lOtsu-j, Co: 15 la warm i
, Mo: 3 di-warm-, All: 5.5'1. Ti:4
．． N1 alloy powder containing 7'j, V:11 and having a composition in which the balance consists of N1 and unavoidable impurities.

C: 1. l*, Cr: 21.0%, Ni: 3
3. Ol, AI: 0.41. Ti: Contains 0.4-, with the remainder consisting of Fe and unavoidable impurities. e alloy powder.

A Cu alloy powder containing 0.5% Al2O, with the remainder consisting of Cu and unavoidable impurities.

Fe: 10%, V: 2'ir, Y: l-
An M alloy powder having a composition containing M and the remainder consisting of M and unavoidable impurities is prepared.

These metal powders were used under the conditions shown in Table 1.

After filling the metal container, it was degassed under the condition of being held at a predetermined temperature within the range of 400 to 600° C. for 12 hours in a vacuum of a pressure canister, and then sealed.

Next, as shown in a perspective view in FIG. 3, the metal container 2 filled with the metal powder and sealed is fitted into the metal frame 1 and fixed at predetermined locations by welding.

Hot pressing is carried out under the same conditions shown in the <m1 table, and the portion 2b of the metal container that protrudes from the metal frame is formed into the metal frame 1.
I pushed it inside. Finally, the metal frame portion was cut and removed, and the outer portion of the metal container was removed by cutting, and the inner portion of the metal container was removed using an acid solution. Methods 1 to 5 of the present invention were carried out, respectively.

Next, the various metal materials obtained as a result were observed for the occurrence of cracks, and their mechanical properties and theoretical density ratios were measured. These results are shown in Table 1.

4 to 8 show the cross-sectional shape of the metal container.

In FIGS. 4 to 8 above, 3 represents the filled metal powder.

The cross-sectional shape of the metal container used in this example is as shown in FIG. is a trapezoid.

Portion 2 that fits within the metal frame 1 of the metal container used in this invention
The cross-sectional shape of a is not limited to the rectangle shown in Figure 4, but may be square as shown in Figures 5 and 8, or trapezoidal as shown in Figure 6. Good too.

Furthermore, the cross-sectional shape of the portion 2b protruding from the metal frame 1 of the metal container used in the present invention may be trapezoidal as shown in FIG. 5, approximately fan-shaped as shown in FIG. It may be approximately trapezoidal in shape like an upside-down dish as shown.

Further, in the above embodiment, the metal container 2 is made of a double-layered composite plate, but is not limited to this, and may be made of a single plate or a 3M composite plate.
The metal frame may be manufactured using the above composite plate. Furthermore, in the above embodiment, a rectangular metal frame is used as the metal frame, but the shape of the metal frame is not limited to the above-mentioned rectangle, and may be triangular, triangular, pentagon.

Other polygonal shapes such as hexagonal shapes, or circular shapes may also be used.

〔Effect of the invention〕

As is clear from the results shown in Table 1, the present invention method 1
The metal materials manufactured by 5 to 5 do not have any cracks, have a theoretical density ratio of 100-1, and have mechanical properties that are equal to or better than those of metal materials manufactured from molten material by hot forging. This shows the above characteristics.

As described above, according to the method of the present invention, a metal powder is used as a raw material, and the material has a theoretical density ratio of 100-1, which has no bore, and is equivalent to a metal material manufactured by hot forging from molten material. It is also possible to manufacture metal materials with mechanical properties higher than those without cracking, and it is also possible to manufacture metal materials that were previously impossible to manufacture by forging, such as stellite alloys. It brings about useful effects.

[Brief explanation of the drawing]

! ! Figure 81 is a perspective view of the metal frame, Figure 2 is a perspective view of the metal container, Figure 3 is a perspective view showing how the metal container is fitted into the metal frame, and Figure 4 is a perspective view of the metal container shown in Figure 2. The cross-sectional views and FIGS. 5 to 8 are cross-sectional views of other metal containers. 1...Metal frame, 2...Metal container. 2a...The part that fits within the metal frame. 2b...Protruding part from the metal frame, 3...Metal powder. 1st Prisoner 3 Figure 8 Circle U-

Claims (1)

[Claims] Metal powder is placed in a metal container in which the cross-sectional shape of the part that fits within the metal frame is square, rectangular, or trapezoid, and the cross-sectional shape of the part that protrudes from the metal frame is trapezoidal, approximately trapezoidal, or approximately fan-shaped. After filling and vacuum-sealing, it is fitted into a polygonal or circular metal frame and fixed. In this case, conditional expression: V_1/V_2=(1-αR)/αR (where V_1: volume of the part protruding from the metal frame) , V_2: Volume of the part that fits in the metal frame, R: Filling rate of metal powder, α:
(indicates correction factor). A method for solidifying metal powder, which satisfies the following, and then heats a metal frame and a metal container, and presses a portion protruding from the metal frame into the metal frame.