JPS61115659A - Production of partially alloyed casting - Google Patents

Abstract

PURPOSE:To produce inexpensively and efficiently a partially alloyed casting by disposing a porous body consisting of fine pieces of a high melting metal into the prescribed part in the mold cavity of a casting mold and pouring a melt of a low melting metal therein. CONSTITUTION:The porous body 6 made into the prescribed shape by compression molding of the relatively high melting metallic powder consisting essentially of W, V, Fe, Ni, Co, Ti, Zr, Mo, Mn, Cr, Si, Cu, Ag, Au, Nb, Ta and the alloy thereof is disposed in the prescribed position in the mold cavity 9 of the casting mold 8 of a high-pressure casting device 7. The melt 10 of the lower melting metal than the above-mentioned high melting metal, consisting of Al, Mg, Zn, Cu, Sn, Pb and the alloy thereof is then poured into the cavity 9. The melt 10 is pressurized by a plunger 11 and is penetrated and alloyed into and with the body 6 and is then solidified. The solidified metal is ejected by a knock-out pin 12 and the partially alloyed casting is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing castings, and more particularly to a method of manufacturing partially alloyed castings.

Conventional technology When specific characteristics are required for a specific part of a casting, it is conceivable to form the entire casting with a metal material that satisfies those characteristics, but in this case, due to issues such as peelability and flowability, It is not possible to manufacture castings with complex shapes,
There are problems such as high cost of casting. For this reason, there is a method of remelting the surface of a specific part of the casting using a laser beam, TIG arc, etc. as a heat source and adding alloying elements to the remelted part to create a partially alloyed casting. is being developed.

Problems to be Solved by the Invention However, since the method using re-am as described above requires a complicated process, it is difficult to produce partially alloyed castings in a low order, and Only the surface of the casting can be alloyed, making it difficult to uniformly alloy a specific part of the casting, and furthermore, there is extreme anisotropy in the direction of crystal growth of the formed alloy phase. Therefore, there are problems such as the unavoidable occurrence of anisotropy in properties such as alloyed strength of the casting.

In view of the above-mentioned problems in the conventional methods of producing partially alloyed castings, the present invention provides a method that can efficiently produce partially alloyed castings in a descending order. The purpose is to do so.

Means for Solving the Problems According to the present invention, the object as described above is to provide a casting made of a first metal, a part of which has a melting point higher than that of the first metal, and a part of which has a melting point higher than that of the first metal. A method for producing a casting alloyed with a second metal that is alloyed with a metal of forming the porous body in a part of the mold cavity of the mold where the part is to be cast, and pouring the molten metal of the first metal into the mold cavity;
This is achieved by a casting manufacturing method in which the first metal and the second metal are alloyed by infiltrating the molten metal into the porous body, and the molten metal is solidified in the mold cavity.

Effects and Effects of the Invention According to the present invention, a porous body is formed which is made of strips of a second metal and has a shape substantially equal to the shape of the part to be alloyed, and the porous body is formed in a mold. A molten metal is placed in a part of the mold cavity where the part to be alloyed is to be cast, and a molten metal of a first metal is poured into the mold cavity, and the molten metal permeates into the porous body. The metal is alloyed with the second metal, and then the molten metal is solidified in the mold cavity, so that a desired specific portion can be alloyed over a desired range, and this By this method, it is possible to easily obtain a casting in which the desired portion is uniformly alloyed.Also, when the surface of the casting is remelted by a laser beam or the like and alloying elements are added to the remelted part, the alloying This makes it possible to avoid problems such as anisotropy in the properties of the converted portion.

According to the present invention, the composition of the part to be alloyed can be freely changed by adjusting the volume ratio, type, etc. of the porous body made of the second metal strips. Further, in the method of the present invention, by using two or more porous bodies made of the same or different second metals, an alloy can be used to impart desired properties to two or more parts of the casting. can be converted into

In addition, the porous body used in the method of the present invention may be powder, chips, flakes, fibers, thin wires, etc. of the second metal, and when the thin pieces are powder, chips, flakes, etc. These may be formed into a porous body by a method such as compression molding, and if the pieces are fibers or thin wires, they may be formed into a porous body by means such as binding.

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

Example 7 Fe powder with an average particle size of 25 μm and a purity of 99.4 wt% was prepared, and the powder was heated at 350° C. for 5 minutes in the atmosphere to forcibly make the surface of the powder soft, and then Fe powder 1
is introduced into the mold S of the compression molding apparatus 2 as shown in FIG.
By compressing at a pressure of 00 k (J/cm'),
A porous body 6 was formed by compression molding with a shape of 80 mm in diameter and 10 fflffl in cl. In this case, 1”
The oxygen content on the surface of the e-powder was 1.53 wt%, and the bulk density of the porous body was 4°7 (1/cc).

Next, after preheating the porous body 6 to 600''C in a vacuum furnace, it is placed on the bottom surface of the mold cavity 9 of the mold 8 of the high-pressure casting apparatus 7, as shown in FIG. A molten metal 10 of pure aluminum (purity 99.7 wt%) with a water temperature of 800°C is poured into a tray 9, and the molten metal is pressurized with a plunger 11 to a pressure of 1000 kg/, After the molten metal was completely solidified, a cylindrical casting 13 was taken out from the mold 8 using a knockout bottle 12.
3 has diameter 8 o Illll 11 height 1001111 (7) dimensions, and iQ from one end as shown in fi3 figure.
It consisted of a portion 14 alloyed with Fe in the range of mm and a portion 15 made only of pure aluminum.

FIG. 4 shows an optical microscopic structure of a cross section of the alloyed portion 14. EPMA for this alloyed part
Analysis and X-ray diffraction tests revealed that the part indicated by a is Fe, the part indicated by b is a mixed phase of At Fe and AlFe3, and the part indicated by 0 is Fe. A
12Fe, and it was observed that almost no part consisting only of pure aluminum remained. Furthermore, it can be seen from FIG. 4 that the above-mentioned phases are uniformly dispersed.

Further, when a tensile test was conducted on the above-mentioned alloyed portion 14 at 450°C, the tensile strength of the portion was 45.
kQ/am', and was recognized to have excellent strength and heat resistance. Although not shown as a specific example, in the case of pure aluminum castings, instead of Fe powder, nickel, vanadium, cobalt, tungsten,
titanium, niobium, tantalum, silicon, molybdenum,
Even when powders of copper or alloys mainly composed of copper are used, alloying occurs between the powders and the pure aluminum molten metal, resulting in an alloyed layer with high strength and heat resistance. This was recognized. In addition, especially when powders of silicon, molybdenum, manganese, or alloys containing these as main components are used, an alloyed layer that not only has excellent strength and heat resistance but also has excellent wear resistance can be obtained. It was approved that

Partially processed in the same manner and under the same conditions as in Example 1 above, except that the molten metal was replaced with depleted magnesium with a purity of 99.8 wt% and the temperature of the molten metal was 750°C. A casting made of pure magnesium alloyed with iron was produced.

Figure 5 shows the average particle size of the powder constituting the porous body: 25
Fig. 3 shows an optical microscopic structure of a cross section of an alloyed layer formed by using nickel powder with a purity of 99.71%. EPMA analysis and Xy
When a diffraction test was performed, the part indicated by a was nickel, and the part indicated by C was composed of M (IgNi and M
It was found that this alloyed layer was a mixed phase with oNi2, and that there was substantially no portion of pure magnesium remaining in this alloyed layer.

In addition, in the case of pure magnesium castings, by using various powders as shown in Table 1 below as powders constituting the porous body, the heat resistance and wear resistance of a part of the pure magnesium castings can be improved. It was observed that properties such as thermal conductivity and thermal conductivity were significantly improved.

Cold 1'' LL AIJ powder with average particle size 7μ and @99.9wt% was used as the first
By compression molding with the compression molding apparatus shown in the figure, the diameter is 3Qmm and the height is 10I! 1Ll11 Bulk density 5,4! : A porous body of I/QC was formed. Next, this porous body was preheated to 600°C in a vacuum furnace, and then placed on the bottom wall of the mold cavity 9 of the mold 8 of the high-pressure casting apparatus shown in FIG. By pouring pure tin molten metal containing 99.5 wt% and having a water temperature of 400°C, and solidifying the molten metal while pressurizing it at a pressure of 500 mm/tn', a diameter of 80 mm and a length of 10 mm was obtained.
A casting having dimensions of 0t++m and consisting of pure tin alloyed with gold in a region of 10m1+1 from one end was produced.

In addition, titanium 0 powder with a purity of 97.6 wt% and a particle size of 10 μ or less was molded using the compression molding apparatus shown in FIG.
11111. A porous body having a height of 10 wv and a bulk density of 2.7 g/CC was formed. Then, after preheating the porous body to 600° C. in a vacuum furnace, the porous body is placed on the bottom wall of the mold cavity 9 of the mold 8 of the high-pressure casting apparatus shown in FIG. Purity 99% inside the mold cavity.
By pouring pure copper molten metal containing 9wt% and having a temperature of 1250°C, and solidifying the molten metal while pressurizing it at a pressure of 1000 kg/IX2, the diameter is 80I111 and the length is 1100I11.
A pure copper casting having dimensions of 10ffi from -i was alloyed with titanium.

FIG. 6 shows an optical microscopic structure of a cross section of the gold alloyed part of the pure tin casting produced as described above. When EPMA analysis and X-ray diffraction tests were performed on this alloy layer, it was found that the part indicated by a is Au, and the part indicated by C is a mixed phase of Au3n and Au3n. Ta. Further, FIG. 7 shows an optical microscopic structure of a cross section of a titanium-alloyed part of the pure copper casting produced as described above. EP about this part
When MA analysis and X-ray diffraction tests were performed, the part indicated by a was Ti, and the part indicated by C was 7"12
It was recognized that it was a mixed phase of Cu and TiQu. Also, from Figure 7, since the Ti powder used was fine,
It can be seen that the structure of the obtained alloyed layer is also very fine.

Additionally, the part alloyed with gold has better thermal conductivity than other parts, and the part alloyed with titanium has better heat resistance than other parts. This was recognized.

Although not shown as a specific example, as shown in Table 1 below, in the case of pure tin castings and pure copper castings, except for the above-mentioned At1 powder and Ti powder, as shown in Table 1. In the case of zinc castings and lead castings, by using the various powders shown in Table 1 below, the heat resistance, thermal conductivity, etc. of a part of each casting can be improved. It was recognized that this could be improved.

1” (Rainbow diameter 0.511111111 degrees 99.8wt% Ni
The surface of ta is forcibly oxidized by heating it at 800°C in the air for 1 hour, thereby reducing the W! The elementary amount of I was limited to 0.73 wt%. Next, by wrapping the Nu; A porous body 17 was formed.

Next, after preheating the porous body 17 to 600'C in a vacuum furnace, the porous body is defined by one fixed die and a movable die 20 of a die casting apparatus 18 as shown in FIG. A pure aluminum molten metal 2 with a purity of 99.7 wt% and a hot water temperature of 780° C. is placed in a mold cavity 21 and introduced into a casting sleeve 23 through an injection port 22.
4 by plunger 25 to 500 k<1/am'
As shown in Figure 10, the molten metal is pressurized at a pressure of
A cylindrical cylinder having dimensions of 100 mm in length and 5 mm from one end and 1.5 nun from the outer peripheral surface of the cylinder, consisting of a nickel-alloyed part 26 and a part 27 made only of pure aluminum. Casting 28 was produced.

FIG. 11 shows an optical microscope structure of a section perpendicular to the Ni line of a portion alloyed with nickel. When EPMA analysis and X-ray diffraction tests were performed on the part alloyed with nickel, the part indicated by a was Ni, the part indicated by b was Ni 2 Al 3, and C
The parts shown are AI and Al3N! A eutectic structure was recognized.

From this example, the pieces constituting the porous body are not limited to powder, but may also be fine wires or fibers, and when fine wires or fibers are used, it is possible to obtain an alloy layer with a specific directionality. Understand what you can do. Further, from this example, it can be inferred that the pieces constituting the porous body may be chips, flakes, or the like.

Table 1 Ni MgCu M(l Si M(11”e M(
l Cu 3n MOMgTi MgAl Sn
Cr M (IGo MOA11l Sn Mo C
uV M! J Cu Zn Si CuW M
LJ At Zn CrCuAl Sn AU
Zll Ni CIJ Au pb fib Cu AI PbZr Cu
AgPb Cu Zn Although the present invention has been described in detail with reference to several embodiments above, the present invention is not limited to these embodiments, and various embodiments may be made within the scope of the present invention. It will be obvious to those skilled in the art that this is possible.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing the compression molding step and high-pressure casting step, respectively, of the casting manufacturing method according to the present invention, and FIG.
The figure is a perspective view showing a cylindrical casting made of pure aluminum partially alloyed with iron, and Figure 4 is an optical cross-section of the iron-alloyed part of the casting shown in Figure 3. A photograph showing the microscopic structure. Figure 5 is an optical microscope photo of a cross section of a worn magnesium casting alloyed with nickel. Figure 6 is a photograph showing a cross section of a worn magnesium casting alloyed with gold. Figure 7 is a photograph showing the optical microscope structure of a cross section of a pure copper casting alloyed with titanium. A perspective view showing the porous body, FIG. 9 is a cross-sectional view showing the casting process performed in a die-casting apparatus using the porous body shown in FIG. 8, and FIG. 10 is the same as shown in FIG. 9. A perspective view showing a cylindrical casting made by the casting process, No. 11
The figure is a photograph showing an optical microscopic structure of a section perpendicular to the Ni line of the nickel-alloyed part of the pure aluminum casting shown in FIG. 10. DESCRIPTION OF SYMBOLS 1... Fe powder, 2... Compression molding device, 3... Mold, 4... Upper punch, 5... Lower punch, 7...
・High pressure casting device, 8... Mold, 9... Mold cavity, 10... Molten metal, 11... Plunger, 12
... Knockara 1-bin, 13... Casting, 14...
- Alloyed part, 15... Part made only of pure aluminum, 16... Ni wire, 17... Porous body,
18...Die casting casting device, 19...Fixed die, 20...Movable die, 21...Mold cavity, 22...Inlet, 23...Casting sleeve, 2
4... Molten metal, 25... Plunger, 26... Alloyed part, 27... Part made only of worn aluminum, 28... Castability Applicant: Toyota Motor Corporation representative
Patent attorney Masa Akashi
Tsuyoshi Figure 3 Figure 4 X400 Figure 5 C Figure 6 X400 - Figure 7 Figure 11 Figure 1O Figure 9

Claims (4)

[Claims] (1) A casting made of a first metal, a part of which is alloyed with a second metal that has a higher melting point than the first metal and is alloyed with the first metal. In the manufacturing method, a porous body is formed from the second metal strip and has a shape substantially equal to the shape of the part, and the porous body is formed into the part of the mold cavity of the casting mold. The first metal and the second metal are alloyed by placing it in the part to be cast, pouring a molten metal of the first metal into the mold cavity, and allowing the molten metal to permeate into the porous body. A method for manufacturing a casting, comprising: solidifying the molten metal in the mold cavity. (2) In the method for manufacturing a casting according to claim 1,
The first metal is aluminum, magnesium, zinc,
A method for producing a casting, characterized in that the metal is selected from the group consisting of copper, tin, lead, and alloys containing these as main components. (3) In the method for manufacturing a casting according to claim 1 or 2, the second metal is tungsten, vanadium, iron, nickel, cobalt, titanium, zirconium, molybdenum, manganese, chromium, silicon. , copper, silver, gold, niobium, tantalum, and alloys containing these as main components. (4) In the method for manufacturing a casting according to any one of claims 1 to 3, in the process of infiltrating the molten metal into the porous body, the molten metal is pressurized. A method for producing a casting characterized by: