JPH04210408A - Manufacture of high strength and high rigidity structural member - Google Patents

Abstract

PURPOSE:To manufacture a high strength and high rigidity structural member by blending a first alloy powder of solid solution phase or amorphous phase and a second alloy powder containing the specific particle diameter of intermetallic compound in matrix with the specific ratio and executing hot forming treatment. CONSTITUTION:The first alloy powder at >=20vol.% and the second alloy powder at <=80% are blended and mixed. The above first alloy powder is made to have single phase structure of the solid solution phase or the amorphous phase, or mixed phase structure thereof. On the other hand, the second alloy powder is made to have structure dispersing the intermetallic compound having <=2mum particle diameter in the matrix and if necessary, composite structure further dispersing the intermetallic compound having >2mum particle diameter. The above raw material powder obtd. by mixing is compacted to make a green compact. Further, heat treatment and hot plastic working are applied to this green compact. By this method, the structural member, which precipitates fine intermetallic compounds in the first alloy powder and maintains heat resistance and high hardness in the second alloy powder and has excellent toughness, strength and rigidity, is obtd.

Description

[Detailed description of the invention]

[00011

[Industrial Field of Application] The present invention relates to a method of manufacturing a high-strength, high-rigidity structural member. [0002] [0002] Conventionally, as a method for manufacturing this type of member,
A method is known in which a raw material powder is produced by applying a rapid solidification method, and then hot plastic working is performed using the raw material powder (see Japanese Patent Laid-Open No. 60-248860). [0003]

Problem to be Solved by the Invention 1 According to the rapid solidification method, a raw material powder having a micro-eutectic structure can be obtained. There is a problem in that the strength and toughness of structural members are low because of coarsening of the structure. [00041] In view of the above, an object of the present invention is to provide the above-mentioned manufacturing method that can obtain a structural member having improved strength and toughness as well as high rigidity. [0005] [Means for Solving the Problems] The method for manufacturing a high-strength, high-rigidity structural member according to the present invention includes a single-phase structure consisting of a solid solution phase, a single-phase structure consisting of an amorphous phase, and a solid solution phase and a non-crystalline phase structure. A composite comprising a first alloy powder having a type of metal structure selected from a mixed phase structure consisting of a crystalline phase and having a blending amount of 20% by volume or more, and an intermetallic compound having a particle size of 2 μm or less dispersed in a matrix. A raw material powder is prepared by mixing with a second alloy powder having a structure and a blending amount of 80% by volume or less,
The method is characterized in that the aggregate of the raw material powder is then subjected to a hot molding treatment.

[0006] It should be noted that the total amount of the first alloy powder is 80 bodies h1
If it exceeds 9/, the strength of the structural member will decrease. Furthermore, if the particle size of the intermetallic compound exceeds 2 μn1, the heat resistance and hardness of the second alloy powder will decrease, making it impossible to improve the rigidity of the structural member. [0007]

[Example] In manufacturing high-strength, high-rigidity structural members,
It has a type of metal structure selected from a single phase structure consisting of a solid solution phase, a single phase structure consisting of an amorphous phase, and a mixed structure consisting of a solid solution phase and an amorphous phase, and the blending amount is 20% by volume or more. A certain first alloy powder and a particle size of 2 in the matrix.
It has a composite structure in which intermetallic compounds of μm or less are dispersed,
A method is carried out in which a raw material powder is prepared by mixing a second alloy powder with a blending amount of 80% by volume or less, and then a hot molding treatment is performed on an aggregate of the raw material powder. [0008] The following aluminum alloys are used as constituent materials of the first and second alloy powders. a. Chemical formula A 1. = Tb
at least one type selected from the first group including
is at least one member selected from the second group including Fe, Co, and Ni, and a, b, and c are each atomic %,
An aluminum alloy having a composition of 85≦a≦97.1≦b≦10.2≦C≦15, chemical formula A 1. T
b X = Zd, T is Y, La, Ce, M
d (Mitsushmetal), at least one kind selected from the first group containing Ca, X is at least one kind selected from the second group containing Fe, Co, and Ni, and Z is T
i, V, Cr, Mn, Zr, Nb, MOIS
at least one member selected from the third group including i and B, a, b, c, and d are each atomic %, and 85≦a≦9
7. Aluminum alloy having a composition where ■≦b≦10.2≦C≦1-5, d≦3 In the aluminum alloy, if the blending ratio of each chemical component deviates from the above range,
Either the aluminum alloy has high hardness and becomes brittle, or its strength decreases, or it has high toughness but low hardness. [A gas atomization method is applied to manufacture the 00091 alloy powder, and the first and second alloy powders are obtained by a subsequent classification process. [0010] The first alloy powder is a solid solution phase, for example, a primary structure in which the volume fraction Vf of a single phase structure consisting of crystal grains with a grain size of less than 30 nm having an FCC structure (face-centered cubic structure) is 90% or more. grain size 30 with fcc structure
A primary structure in which the volume fraction Vf of a mixed phase structure consisting of less than nm crystal grains and an amorphous phase is 90% or more, and the volume fraction Vf of the amorphous phase in the mixed structure is 80% or less. This applies to items such as [00111 A green compact is used as an aggregate of raw material powder, and the green compact is formed by cold pressing, CI
P processing etc. are applied. [0012] The hot forming process includes a process of heat treating the green compact and a hot plastic working process. [0013] The heat treatment is performed in the first alloy powder to obtain a secondary structure having a composite structure in which intermetallic compounds are uniformly dispersed and precipitated in a matrix made of crystal grains, and this heat treatment The thermal stability of the powder can be improved. Since the particle size of the intermetallic compound in the second alloy powder is specified as described above, it maintains heat resistance and high hardness even after the heat treatment. [0014] Heat The degree of heat treatment is set to the decomposition temperature of single phase and mixed structure ±100°C. If the heat treatment temperature is less than -100°C, the decomposition temperature of the single-phase and mixed structures, it will take a long time to decompose those structures, resulting in poor productivity. On the other hand, if it exceeds the decomposition temperature +100°C, the crystal grains and Intermetallic compounds become coarse and cause alloy embrittlement. [0015] The metal structure of the first alloy powder after heat treatment is preferably a secondary structure having a composite structure in which an intermetallic compound is uniformly dispersed in a matrix made of crystal grains with a grain size of 400 nm or less. [0016] Note that when the volume fraction Vf of the single-phase and mixed-phase structures in the primary structure becomes less than 90%, coarse intermetallic compounds appear in the structure other than the single-phase and mixed-phase structures, and the intermetallic compounds remains in the secondary structure, leading to embrittlement of the alloy. [0017] Furthermore, when the grain size of the crystal grains in the single-phase and mixed-phase structures exceeds 30 nm, the strength of the alloy decreases because the grain size of the crystal grains in the composite structure of the secondary structure exceeds 400 nm. [0018] Further, if the volume fraction Vf of the amorphous phase in the mixed structure exceeds 80%, a uniform secondary structure cannot be obtained. [0019] Hot plastic working includes hot extrusion, HI
P treatment, warm forging, hot forging, etc. are applied. [00201 When hot plastic working is applied to the green compact after heat treatment, the first and second alloy powders do not undergo structural changes or coarsening under the thermal history, which improves the strength and strength of the structural member. It is possible to improve toughness. [00211 Furthermore, with the blending of the second alloy powder having a relatively large intermetallic compound, it is possible to improve the Young's modulus of the structural member, and thus the rigidity. [00221 Next, a specific example will be explained. [00231 A 192 Fe4Y3 Mnt as the aluminum alloy constituting the first and second alloy powders
(values are atomic %) were selected. [0024] In producing the alloy powder, a He gas atomization method was applied. That is, in order to form an alloy powder having the above composition, an AI-Fe-Y-Mn-based master alloy was melted by high-frequency melting, and the injection pressure of He gas was 100 kg f.
The alloy powder was produced under the application of the gas atomization method set at /cm2. [0025] The alloy powder was classified and the metal structure of the alloy powder having each particle size was examined, and the results shown in Table 1 were obtained. [0026]

[Table 1] [00271 In Table 1, the mixed phase structure consists of crystal grains with a grain size of 17 nm having an fcc structure and an amorphous phase, and the volume fraction Vf of the mixed phase structure is 95%. The volume fraction is 60%. The decomposition temperature of this mixed structure is 384°C. [0028] Alloy powder (1) corresponds to the first alloy powder in the present invention, and alloy powders (2) to (6) correspond to the second alloy powder in the present invention. Alloy powder (7) is a comparative example. [0029] FIG. 1 shows the hardness of each alloy powder (1) to (7), where line C1 is the case of immature treatment and line C2 is the hardness of 400.
This applies to cases where heat treatment is performed at ℃ for 1 hour. In both lines C+ and C2, points (1) to (7) correspond to alloy powders (1) to (7), respectively. [00301 As is clear from FIG. 1, in the hardness change due to the heat treatment, the alloy powder (1
) is the second alloy powder compared to (2) to (6
) has a small change in hardness. Especially 1 alloy powder (4). In (5), there is almost no change in hardness. [00311 Considering the decrease in hardness due to the heat treatment, the average particle size of the intermetallic compound in the second alloy powder is 2.
．． 0 μm or less, therefore, alloy powders (2) to (6) are suitable, and in these alloy powders (2) to (6),
Due to the crystallization of relatively large intermetallic compounds, the matrix has both physical properties such as heat resistance and high hardness. [0032] When obtaining a second alloy powder by precipitating an intermetallic compound by subjecting the first alloy powder to heat treatment,
In order to grow the intermetallic compound to a particle size of approximately 1 μm,
Heat treatment at 50° C. for 1 hour is required, and when such heat treatment is performed, the hardness of the second alloy powder is extremely reduced as shown by point d in FIG. [0033] Therefore, it is advantageous to use a crystallized intermetallic compound as the second alloy powder. [00343 Next, alloy powder (1), which is the first alloy powder shown in Table 1, and each alloy powder (2), which is the second alloy powder, were prepared.
) to (6) and alloy powder (7) which is a comparative example alloy powder
Various structural members were manufactured using this method. [0035] As raw material powders, five types of alloy powders (1) and alloy powders (2) to (6) were mixed separately, and alloy powder (1) was mixed with comparative example alloy powder (7). was prepared. a. Put the raw material powder into a rubber transparent body,
It was then subjected to CIP treatment under a pressure of 4000 kgf/cm2, resulting in a diameter of 58 mm, a length of 40 mm, and a density of 87%.
A short cylindrical green compact was obtained. b. The green compacts were loaded into four bodies made of aluminum alloy (AA standard 6061 material) to obtain billets with an outer diameter of 78 m and a length of 80 mm. C1
Inside the billet 0. After reducing the pressure to 2 x 10" Torr, the green compact was heat treated at 400°C for 1 hour in a Matsufuru furnace. The billet was then loaded into the container of a single-acting hot extrusion processing machine. [0036] In the hot extrusion processing machine, the maximum pressing force was set to 500 tons, the inner diameter of the container was 80 mm, the preheating temperature of the container was set to 400 ° C, and the diameter of the die hole was set to 22 mm. was extruded from a die to obtain a round bar-shaped structural member. Figure 2 shows the tensile strength of various structural members, and Figure 3 shows the Young's modulus of each structural member. , corresponds to the case where alloy powders (2) to (6) are used as the second alloy powder, and line e7 corresponds to the case where the comparison side powder or powder (7) is used as the mixed powder. Point f is the case where alloy powder (7) is used as the mixed powder. When powder (1) is used alone, points g2 to g7
are alloy powders (2) to (6) and comparative example alloy powder (7)
This corresponds to each case when used alone. [0038] As is clear from Figure 2, line C: - e6, the strength of the structural member is ensured by setting the blending amount of the second alloy powder to 80 volume % or less, preferably 60 volume % or less. I can do it. [00391 In the case of line c7 in FIG. 2, the strength is lower than that of the structural member according to the present invention. Moreover, as is clear from the lines e2 to e6 in FIG. 3, it can be seen that the Young's modulus of each structural member, and thus the rigidity, increases as the blending amount of the second alloy powder increases. However, the blending amount of the second alloy powder is set to 80% by volume or less in view of the above-mentioned strength. [00403 In FIG. 3, line e7, even if Comparative Example Alloy Powder (7) is blended, the effect of improving Young's modulus is extremely small. [0041,1 From Figure 22 and Figure 3, 20% by volume or more of the first
It is clear that by using a raw material powder consisting of an alloy powder and 80% by volume or less of a second alloy powder, a structural member with high strength and high rigidity can be obtained. [0042] When alloy powder (2) is used as the second alloy powder, the line hr-hn in FIG. 4 represents the tensile strength of each structural member, and the lines h1 to h4 in FIG. 5 represent the Young's strength of each structural member. The percentage is shown for each. At point kl~, 4 is alloy powder (1
) is used alone, and the point rrl −m4 corresponds to the case where alloy powder (2) is used alone. [0043] As shown in Table 2, the structural members shown by the lines hi-h4 in FIG. 42 and FIG. 5 have different manufacturing conditions and the maximum grain size of the precipitated intermetallic compound. [0044]

[Table 2] [00451 Figure 41 As is clear from Figure 5 and lines h1 to h3 in Table 2, the maximum particle size of the precipitated intermetallic compound was 1.
When the thickness is defined as 071 m or less, a structural member with high strength and high rigidity can be obtained. [00461 As shown by line h4 in FIG. 5, when the maximum particle size of the precipitated intermetallic compound exceeds 1.0 μm, almost no improvement in Young's modulus can be expected. [0047] Table 3 shows alloy powder (1
), and using alloy powder (2), which is the first constituent powder, and comparative example alloy powder (7), which is the second constituent powder, as the second alloy powder. . For comparison, Table 3 also shows structural members p1 to p3 using alloy powder (]-) and comparative example alloy powder (7), and structural member p5 using alloy powder (1) alone. There is. [00483

[Table 3] [0049] From Table 3, when alloy powder (2) and comparative example alloy powder (7) are used together, structural members n+, n2
When the amount of Comparative Example Alloy Powder (7) is set to 5% by volume or less, both strength and rigidity can be improved. [00501 Next, the particle sizes of the first and second alloy powders will be considered. A19 under application of He gas atomization method
When an alloy powder having a composition of 2Fe4Y3Mnt was produced and classified so that the particle size a was 22μm≦a≦44μm, an alloy powder with a mixed phase structure consisting of crystal grains with an FCC structure and an amorphous phase was obtained. was gotten. This alloy powder is referred to as a first alloy powder. [00511 Also, the same composition (A192
When an alloy powder with Fe<Y3Mn+) was produced and classified so that the particle size a was 11 μm≦a≦22 lLm, more than 90% of the alloy powder had an average particle size of 0. 1~0
．． It contained a crystallized intermetallic compound of 4 μm. This alloy powder is referred to as a second alloy powder. [0052] In this case, contrary to the above embodiment, the first alloy powder has a larger particle size than the second alloy powder. [0053] Table 4 shows various structural members r1 manufactured by the same method as in the above example using the first and second alloy powders whose particle sizes are inversely related as described above. ~ r8 [0054] [Table 4] [00551 Table 5 shows the above alloy powder (
1), and the alloy powder (2) as a second alloy powder,
The tensile properties of various structural members SI to s8 manufactured using the mixed powder of (3) in the same manner as in the above example are shown. [0056]

[Table 5] [00571 Table 49 As is clear from comparing Table 5,
As shown in Table 4, when the particle size of the first alloy powder is made larger than that of the second alloy powder, relatively large variations occur in the tensile properties of the structural member rl-r8. [0058] This is because the thermally stable second alloy powder tends to aggregate due to its small particle size, and as a result,
This seems to be because the first and second alloy powders cannot be uniformly dispersed and mixed when preparing the raw material powder. [0059]

According to the present invention, a structural member having high strength, high toughness, and high rigidity can be obtained by using a raw material powder in which a specific amount of the first and second alloy powders having the specific composition is mixed. be able to.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the particle size of a crystallized intermetallic compound and the hardness of an alloy powder.

FIG. 2 is a graph showing the relationship between the blending amount of the second alloy powder and the tensile strength of the structural member.

FIG. 3 is a graph showing the relationship between the blending amount of the second alloy powder and the Young's modulus of the structural member.

FIG. 4 is a graph showing the relationship between the blending amount of alloy powder (2) and the tensile strength of a structural member.

FIG. 5 is a graph showing the relationship between the blending amount of alloy powder (2) and the Young's modulus of a structural member.

[Figure 5]

Claims (2)

[Claims] [Claim 1] A metal structure having a type of metal structure selected from a single phase structure consisting of a solid solution phase, a single phase structure consisting of an amorphous phase, and a mixed phase structure consisting of a solid solution phase and an amorphous phase, and in which the blending amount is A first alloy powder having a content of 20% by volume or more and a second alloy powder having a composite structure in which an intermetallic compound with a particle size of 2 μm or less is dispersed in a matrix and having a blending amount of 80% by volume or less are mixed. A method for producing a high-strength, high-rigidity structural member, which comprises preparing a raw material powder using a hot molding method, and then subjecting the aggregate of the raw material powder to a hot molding process. [Claim 2] It has a type of metal structure selected from a single phase structure consisting of a solid solution phase, a single phase structure consisting of an amorphous phase, and a mixed phase structure consisting of a solid solution phase and an amorphous phase, and the amount of the compound is A first alloy powder having a content of 20% by volume or more, a first constituent powder having a composite structure in which an intermetallic compound with a particle size of 2 μm or less is dispersed in a matrix, and an intermetallic compound with a particle size of more than 2 μm dispersed in the matrix. A raw material powder is prepared by mixing with a second alloy powder containing a second component powder having a composite structure and having a blending amount of 80% by volume or less, and then hot molding treatment is performed on the aggregate of the raw material powder. A method for manufacturing a high-strength, high-rigidity structural member, characterized by subjecting it to.