JP2019108579A - Aluminum alloy material, and method for producing aluminum alloy product - Google Patents

Abstract

To provide an aluminum alloy material reduced in deterioration of high temperature strength and capable of securing fixed or almost fixed sufficient strength from an ordinary temperature region to a high temperature region of about 150°C.SOLUTION: Provided is an aluminum alloy material having a composition comprising, by mass, 7.0 to 15.0% Ce, 0.5 to 10.0% Cu and 0.2 to 3.0% Mg, in which the content of Ni is 0.3% or lower, and the balance Al with inevitable impurities.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of producing an aluminum alloy material and an aluminum alloy product that can be used in a high temperature range up to 150 ° C., for example, as a transportation device part or the like.

  From the point of view of environmental protection on a global scale, improvement of fuel consumption by weight reduction is one of the important goals in transportation equipment such as automobiles, and its structural material has high specific strength and cross-sectional shape. Aluminum alloys are widely used because of their high degree of freedom, etc., and their demand has been increasing in recent years.

  Among them, aluminum alloy materials and the like used for internal combustion engine parts (for example, pistons etc.), turbocharger parts (for example compressor wheels etc.), etc. have sufficient strength in high temperature range to increase output of internal combustion engines. Is required.

  Conventionally, an aluminum alloy material excellent in high temperature characteristics is used for these applications. For example, JIS A2618 alloy or A2219 alloy which is an Al-Cu based alloy is used as a heat resistant aluminum alloy forging material. However, in these aluminum alloys, the reduction in strength was significant at high temperatures above 120 ° C.

  Therefore, Fe: 5.0 to 15% by weight, Ce: 0.5 to 5% by weight, and Co: 0.5 to 15% by weight, Cr: can improve the high temperature strength of the aluminum alloy material. 0.7 to 15% by weight, Zr: 0.3 to 10% by weight, and Ti: 0.5 to 10% by weight, one or more of them, and the total amount of additive elements is 25% by weight or less, A manufacturing method has been proposed in which a molten Al alloy having residual Al and unavoidable impurities is rapidly solidified by gas atomization to form a powder, and this is hot-pressed and shaped (Patent Document 1).

In addition, one or both of Zr: 0.05 to 0.50 wt% and Sc: 0.05 to 1.0 wt%,
(A) The size of the Al-Zr dispersed particles is 35 to 450 angstrom, and the interval is 0.005 to 0.6 μm. (B) The size of the Al-Sc dispersed particles is 35 to 450 angstrom, the interval is 0.005 The aluminum alloy material of the structure which has a microstructure which satisfies at least any one of said (a) and (b) which is -0.6 micrometer is proposed (patent document 2). That is, by dispersing Al-Zr-based precipitated fine particles and / or Al-Sc-based precipitated fine particles in the metal structure and controlling the size of the fine particles and the distance between the fine particles, recrystallization of the aluminum alloy material can be suppressed. It is disclosed that an aluminum alloy material having improved strength in

Unexamined-Japanese-Patent No. 1-319643 JP-A-9-95750

  In the technique described in Patent Document 1, in order to improve the strength of the aluminum alloy material in the high temperature range, the average size of the intermetallic compound must be reduced to 0.07 to 1 μm. It is necessary to use gas atomization as a method. However, since the gas atomization method requires a complicated apparatus in addition to a large number of manufacturing steps, its manufacturing cost is significantly higher than that of the casting method.

  Moreover, in the aluminum alloy materials described in Patent Documents 1 and 2, when the temperature reaches a high temperature (150 ° C.), the strength decreases. For this reason, when manufacturing parts expected to be used in a high temperature range, such as transportation equipment parts, it was necessary to perform strength design including a strength reduction margin in the high temperature range. That is, the strength at normal temperature is improved (with anticipation of the reduction in strength in the high temperature range), and the strength is evaluated in multiple temperature environments in the high temperature area used, and the reduction in strength in the high temperature range is taken into consideration Need to determine the quality assurance value of strength. Furthermore, the evaluation of high temperature strength also required complicated equipment and a great deal of time.

  Therefore, development of an aluminum alloy material capable of securing a substantially constant and sufficient strength from a normal temperature range to a high temperature range of about 150 ° C. is desired, but the study of an aluminum alloy material having such characteristics is The fact is that it has not been done until now. That is, conventionally, there has been no means for suppressing the reduction in strength of the aluminum alloy material in the high temperature range (150 ° C.).

  The present invention has been made in view of such technical background, and it is an aluminum alloy which can maintain a constant or substantially constant sufficient strength from a normal temperature range to a high temperature range of about 150 ° C. with a small decrease in high temperature strength. It is an object of the present invention to provide a method of producing a material and an aluminum alloy product.

  In order to achieve the above object, as a result of intensive studies, the present inventors included Ce in an Al-Cu-Mg-based alloy in a range of 7.0% by mass to 15.0% by mass and a Ni content By restricting the content to 0.3% by mass or less, it is possible to remarkably improve the strength reduction in the high temperature region while suppressing the formation of a compound containing coarse Ni and Ce, and from the normal temperature region to a high temperature region of about 150 ° C. The present invention has been completed as a result of finding that a certain sufficient strength can be secured.

  That is, to achieve the above object, the present invention provides the following means.

  [1] Ce: 7.0% by mass to 15.0% by mass, Cu: 0.5% by mass to 10.0% by mass, Mg: 0.2% by mass to 3.0% by mass, and Ni The aluminum alloy material whose content rate is 0.3 mass% or less, and remainder becomes from Al and an unavoidable impurity.

  [2] Assuming that the tensile strength at 150 ° C. of the aluminum alloy material is “A” (MPa) and the normal temperature tensile strength of the aluminum alloy material is “B” (MPa), 0.95 <A / B < The aluminum alloy material according to item 1 above, which is 1.05.

  [3] The aluminum alloy is one or more selected from the group consisting of Fe, Mn, Sn, Sc, Ti, Zr, V, Cr, Co, Mo, Ag, Ta, Hf, Nb and Sr. The aluminum alloy material according to item 1 or 2, wherein each of the two or more metals is contained in an amount of 0.01% by mass to 5.0% by mass.

[4] Ce: 7.0% by mass to 15.0% by mass, Cu: 0.5% by mass to 10.0% by mass, Mg: 0.2% by mass to 3.0% by mass, and Ni A molten metal forming step of obtaining a molten metal of an aluminum alloy having a content of 0.3 mass% or less and the balance being Al and unavoidable impurities;
A casting process for obtaining a cast material by casting the obtained molten metal, and a method of producing an aluminum alloy product.

  [5] Assuming that the tensile strength at 150 ° C. of the obtained cast material is “A” (MPa) and the normal temperature tensile strength of the cast material is “B” (MPa), 0.95 <A / B The manufacturing method of the aluminum alloy products of the preceding clause 4 which is <1.05.

  [6] The aluminum alloy molten metal is further selected from the group consisting of Fe, Mn, Sn, Sc, Ti, Zr, W, Cr, Co, Mo, Ag, Ta, Hf, Nb and Sr. Or the manufacturing method of the aluminum alloy products of the preceding clause 4 or 5 which contain 2 or more types of metal, respectively 0.01 mass%-5.0 mass%.

  According to the invention [1], it is possible to provide an aluminum alloy material capable of remarkably improving strength reduction in a high temperature range and capable of stably securing sufficient strength from a normal temperature range to a high temperature range of about 150 ° C. Therefore, for example, by measuring the normal temperature strength of the aluminum alloy material of the present invention, it is possible to evaluate the material and guarantee the quality without evaluating the high temperature strength at 150 ° C. which requires much time and cost.

  In the invention of [2], since the strength from the normal temperature range to the high temperature range of about 150 ° C. is more stable, the material can be evaluated without evaluating the high temperature strength, and the quality assurance accuracy Can also be improved.

  According to the invention [3], it is possible to provide an aluminum alloy material in which the tensile strength in a high temperature range is further enhanced.

  According to the invention [4], it is possible to manufacture an aluminum alloy product capable of stably securing sufficient strength from a normal temperature range to a high temperature range of about 150 ° C.

  In the invention of [5], the strength from the normal temperature range to the high temperature range of about 150 ° C. is more stable, and it becomes possible to evaluate the material without evaluating the high temperature strength, and at the same time the accuracy of quality assurance An aluminum alloy product that can be further improved can be manufactured.

  In the invention of [6], an aluminum alloy product can be produced in which the tensile strength in the high temperature range is further enhanced.

It is a perspective view showing an example of aluminum alloy products concerning the present invention.

  Hereinafter, embodiments of an aluminum alloy material according to the present invention and a method of manufacturing an aluminum alloy product according to the present invention will be described in detail. The embodiments described below are merely examples, and the present invention is not limited to the illustrated embodiments, and can be appropriately modified without departing from the technical concept of the present invention.

  The aluminum alloy material according to the present invention has Ce: 7.0% by mass to 15.0% by mass, Cu: 0.5% by mass to 10.0% by mass, Mg: 0.2% by mass to 3.0% by mass The Ni content is 0.3% by mass or less (including Ni-free inclusion; 0% by mass including Ni content), and the balance is Al and unavoidable impurities. With such an alloy composition, it is possible to provide an aluminum alloy material capable of remarkably improving strength reduction in a high temperature range and securing substantially constant and sufficient sufficient strength from a normal temperature range to a high temperature range of about 150 ° C. Therefore, for example, by measuring the normal temperature strength of the aluminum alloy material of the present invention, it is possible to evaluate the material and guarantee the quality without evaluating the high temperature strength which requires much time and cost. The aluminum alloy material of the present invention is suitable, for example, in applications used in a high temperature range up to 150 ° C.

  Next, the method for producing an aluminum alloy product according to the present invention will be described. The production method contains Ce: 7.0% by mass to 15.0% by mass, Cu: 0.5% by mass to 10.0% by mass, Mg: 0.2% by mass to 3.0% by mass, A molten metal forming step for obtaining a molten metal of an aluminum alloy having a Ni content of 0.3% by mass or less and the balance being Al and unavoidable impurities, and a casting step for obtaining a cast material by casting the obtained molten metal And.

  The molten metal forming step contains Ce: 7.0% by mass to 15.0% by mass, Cu: 0.5% by mass to 10.0% by mass, Mg: 0.2% by mass to 3.0% by mass A molten aluminum alloy is prepared, which is prepared so that the content of Ni is 0.3% by mass or less and the balance is composed of Al and unavoidable impurities.

  Next, a cast material is obtained by casting the obtained molten metal (casting process). The casting method is not particularly limited, and a conventionally known method may be used, and examples thereof include a continuous casting and rolling method, a semi-continuous casting method (DC casting method), and the like.

  As described below, one of the processes such as the homogenization heat treatment process, the hot forging process, the solution treatment process, the quenching process, the artificial age hardening process, the cold compression (processing) process, etc., as necessary. Alternatively, a plurality of steps may be selected and implemented.

(Homogenization heat treatment process)
By performing homogenization heat treatment on the obtained cast material, homogenization of microsegregation caused by solidification, precipitation of supersaturated solid solution element, and change of metastable phase to equilibrium phase are performed. By the homogenizing heat treatment, the size of the intermetallic compound can be reduced while preventing the melting of Al—Ce eutectic Ce. Thus, as the intermetallic compound becomes smaller, the destruction starting from the intermetallic compound is suppressed, and the strength is further improved. Further, by performing the homogenization heat treatment, each element contained in the intermetallic compound is uniformly diffused into the base material, and it is possible to further improve the strength by solid solution strengthening and precipitation.

  The homogenization heat treatment is preferably performed in a temperature range in which eutectic melting does not occur, and as high as possible. By performing the homogenizing heat treatment under such conditions, dissolution and diffusion of the intermetallic compound into the base material are effectively performed. As a result, the size of the intermetallic compound can be reduced.

  It is preferable to set the processing temperature of the said homogenization heat processing to the range of 470 degreeC-520 degreeC. By heat treatment at a temperature of 470 ° C. or more, an intermetallic compound such as a crystallized product of a casting material is solid-solved, and sufficient homogenization can be performed, and by heat treatment at a temperature of 520 ° C. or less It can prevent burning.

(Hot forging process)
The temperature conditions of the hot forging, as well as the wrought ratio described later, have a relationship in that the characteristics of the aluminum alloy are expressed with good reproducibility, that is, the microstructure after the solution treatment of the aluminum alloy is equiaxed grains and It is possible to Among them, hot forging is preferably performed at a temperature of 420 ° C. to 500 ° C. Since the hot forging temperature is 420 ° C. or higher, generation of cracks in the aluminum alloy can be prevented during hot forging, and the hot forging temperature is 500 ° C. or lower, so that the structure of the aluminum alloy Since coarser crystal grains are less likely to be generated, the high temperature strength of the aluminum alloy material can be further improved (that is, the strength reduction at high temperatures can be sufficiently suppressed).

(Solution treatment process, hardening treatment process, artificial aging treatment process)
Next, the solution treatment step, the quenching treatment step, and the artificial aging treatment step will be described. The solution treatment is a heat treatment in which the aluminum alloy is maintained at a high temperature and then quenched to form a supersaturated solid solution. The quenching treatment is a heat treatment that rapidly cools the solid solution obtained by the solution treatment to form a supersaturated solid solution. The artificial age hardening treatment is a heat treatment for heating and holding the aluminum alloy at a relatively low temperature to precipitate an element which is solid-solved in supersaturation, thereby giving an appropriate hardness. By performing these heat treatments (solution treatment, hardening treatment, artificial age hardening treatment), fine precipitates are uniformly dispersed, eutectic Si turns into spheres, and strength, ductility and toughness are highly balanced. Aluminum alloy material can be obtained.

  These heat treatment conditions may be selected according to the component composition, the required characteristics, and the like. For example, the solution treatment may be quenching after heating and cooling at 450 ° C. to 550 ° C. for 0.5 hours to 10 hours. Among them, the solution treatment is more preferably performed by setting the heating temperature to 490 ° C. to 530 ° C. and the holding time to 1 hour to 5 hours, and in this case, the balance between cost and characteristics is better.

  Moreover, what is necessary is just to hold | maintain artificial age hardening process at 120 degreeC-280 degreeC for 0.5 hour-20 hours, for example. Above all, it is more preferable to carry out the artificial age hardening process by setting the heating temperature to 170 ° C. to 270 ° C. and holding time to 1 hour to 10 hours, and in this case, the balance between cost and characteristics is better.

(Cold compression process)
In cold compression, using a mold tool under normal temperature (room temperature), an external force exceeding the elastic limit is applied to the aluminum alloy material, causing permanent strain, and processing (compression molding) into a desired shape or size. It is something to do. Since the molding is performed at normal temperature, the molding accuracy is high, and the processing in the post-process can be reduced, and the strength of the aluminum alloy material can be improved because the metal fibers are hard to stand up.

  Next, the composition of the “aluminum alloy” in the method for manufacturing an aluminum alloy material and an aluminum alloy product according to the present invention described above will be described in detail below. The aluminum alloy contains Ce: 7.0% by mass to 15.0% by mass, Cu: 0.5% by mass to 10.0% by mass, Mg: 0.2% by mass to 3.0% by mass, It is an aluminum alloy having a Ni content of 0.3% by mass or less (including Ni-free content; that is, a Ni content of 0 mass%) and the balance of Al and unavoidable impurities.

  The Ce (component) is an important element in the present invention, and is dispersed along the grain boundaries of α-aluminum crystal grains as Al—Ce eutectic Ce during crystallization as an intermetallic compound with Al. It precipitates and contributes to the strength improvement by dispersion strengthening. Further, the intermetallic compound precipitated at the grain boundaries can suppress the enlargement of the aluminum crystal grains at high temperatures, which contributes to the improvement of the heat resistance. The Ce content in the aluminum alloy is in the range of 7.0% by mass to 15.0% by mass. When the Ce content is less than 7.0% by mass, the amount of intermetallic compounds deposited in Al grain boundaries decreases, and the effect of suppressing the growth of aluminum crystal grains at high temperatures can not be obtained, and high temperature strength is obtained. descend. In addition, when the Ce content exceeds 15.0% by mass, the precipitated intermetallic compound is enlarged and the toughness is lowered. Among them, the Ce content in the aluminum alloy is preferably in the range of 9.0% by mass to 12.0% by mass.

The Cu (component) is an element effective to impart age hardenability to the alloy in cooperation with Mg. When Cu is added together with Mg, normal temperature strength and high temperature strength can be further improved by performing solution treatment, hardening treatment, and age hardening treatment as a heat treatment type alloy. The Cu content in the aluminum alloy is in the range of 0.5% by mass to 10.0% by mass. When the Cu content is less than 0.5% by mass, sufficient age hardenability can not be obtained, and hence the effect of improving the strength is small. In addition, when the Cu content exceeds 10.0% by mass, the age hardenability saturates, so the effect of improving the strength decreases and the coarse Al ₂ Cu that reduces the elongation is likely to crystallize, so the workability Decreases. Among them, the Cu content in the aluminum alloy is preferably in the range of 2.0% by mass to 5.0% by mass.

  The Mg (component) is an element effective for imparting age hardenability to the alloy in cooperation with Cu as described above. When Mg is added together with Cu, normal temperature strength and high temperature strength can be further improved by performing solution treatment, hardening treatment, and age hardening treatment as a heat treatment type alloy. The Mg content in the aluminum alloy is in the range of 0.2% by mass to 3.0% by mass. When the Mg content is less than 0.2% by mass, sufficient age hardenability can not be obtained, and hence the effect of improving the strength is small. In addition, when the Mg content exceeds 3.0% by mass, a coarse intermetallic compound is formed, and the strength is reduced. Among them, the Mg content in the aluminum alloy is preferably in the range of 1.0% by mass to 2.0% by mass.

  The Ni (component) is liable to form an intermetallic compound with Ce, and when it is contained in excess of 0.3% by mass, coarse intermetallic compounds containing Ni and Ce in the crystal grains and in the crystal grain boundaries are crystallized. As well as reducing mechanical properties, corrosion resistance and toughness are likely to be reduced. Therefore, the Ni content in the aluminum alloy is 0.3% by mass or less (including Ni-free; that is, the Ni content also includes 0% by mass). Among them, the Ni content in the aluminum alloy is preferably 0.25% by mass or less.

  In the present invention, the aluminum alloy is further selected from the group consisting of Fe, Mn, Sn, Sc, Ti, Zr, W, Cr, Co, Mo, Ag, Ta, Hf, Nb and Sr. Or it is good also as composition (composition) which contains 0.01 mass%-5.0 mass% of 2 or more types of elements, respectively. Each of these elements has a slow diffusion rate in the aluminum alloy, so that fine intermetallic compounds can be crystallized in the Al matrix to further improve the high temperature strength of the aluminum alloy material. With any of the elements, when the content is 0.01% by mass or more, the effect (further improvement of the high temperature strength of the alloy material) can be sufficiently obtained, and the content is 5.0%. By being% or less, precipitation as a coarse intermetallic compound can be suppressed, and a decrease in high temperature strength and a decrease in toughness of the aluminum alloy material are not caused. In addition, when making an aluminum alloy contain 2 or more types of the said elements, in order to suppress formation of a coarse intermetallic compound, the total value of the content rate of the said element (2 or more types of elements) is 8.0 mass It is preferable to set it as% or less.

  Next, specific examples of the present invention will be described, but the present invention is not particularly limited to these examples.

Example 1
Aluminum alloy containing Ce: 10.0 mass%, Cu: 4.50 mass%, Mg: 0.55 mass%, Ni: 0.16 mass%, Al: 84.79 mass%, and containing unavoidable impurities After heating to obtain a molten aluminum alloy, continuous casting was performed using the molten aluminum alloy at a casting diameter of 57 mm to obtain a continuous cast material. The obtained continuous cast material was subjected to homogenization heat treatment at 500 ° C. for 7 hours, and then air cooled.

  The air-cooled continuous cast material is cut to a length of 80 mm, heated at 510 ° C. for 3 hours for solution treatment, then placed in 25 ° C. water for water quenching, then at 260 ° C. for 1 hour The mixture was heated and subjected to an artificial aging treatment to obtain a cylindrical cast material 1 shown in FIG.

Example 2
As a molten aluminum alloy, Ce: 8.0% by mass, Cu: 4.50% by mass, Mg: 0.55% by mass, Ni: 0.16% by mass, Al: 86.79% by mass, unavoidable impurities A cast material 1 was obtained in the same manner as in Example 1 except that a molten aluminum alloy containing H was used.

Example 3
Unwanted impurities containing as molten aluminum alloy, Ce: 14.0% by mass, Cu: 4.50% by mass, Mg: 0.55% by mass, Ni: 0.16% by mass, Al: 80.79% by mass A cast material 1 was obtained in the same manner as in Example 1 except that a molten aluminum alloy containing H was used.

Example 4
As a molten aluminum alloy, Ce: 10.0 mass%, Cu: 1.50 mass%, Mg: 0.55 mass%, Ni: 0.16 mass%, Al: 87.79 mass%, unavoidable impurities A cast material 1 was obtained in the same manner as in Example 1 except that a molten aluminum alloy containing H was used.

Example 5
As a molten aluminum alloy, it contains 10.0 mass% of Ce, 8.00 mass% of Cu, 0.55 mass% of Mg, 0.16 mass% of Ni, 81.29 mass% of Al, and unavoidable impurities A cast material 1 was obtained in the same manner as in Example 1 except that a molten aluminum alloy containing H was used.

Example 6
As a molten aluminum alloy, it contains 10.0 mass% of Ce, 4.50 mass% of Cu, 1.00 mass% of Mg, 0.16 mass% of Ni, 84.34 mass% of Al, and unavoidable impurities A cast material 1 was obtained in the same manner as in Example 1 except that a molten aluminum alloy containing H was used.

Example 7
As a molten aluminum alloy, Ce: 10.0 mass%, Cu: 4.50 mass%, Mg: 2.00 mass%, Ni: 0.16 mass%, Al: 83.34 mass%, unavoidable impurities A cast material 1 was obtained in the same manner as in Example 1 except that a molten aluminum alloy containing H was used.

Example 8
An aluminum alloy melt containing 10.0 mass% of Ce, 4.50 mass% of Cu, 0.55 mass% of Mg, 84.95 mass% of Al as molten aluminum alloy and containing unavoidable impurities is used. A cast material 1 was obtained in the same manner as in Example 1 except for the above.

Example 9
As a molten aluminum alloy, Ce: 10.0 mass%, Cu: 4.50 mass%, Mg: 0.55 mass%, Ni: 0.10 mass%, Al: 84.85 mass%, unavoidable impurities A cast material 1 was obtained in the same manner as in Example 1 except that a molten aluminum alloy containing H was used.

Example 10
As a molten aluminum alloy, Ce: 10.0 mass%, Cu: 4.50 mass%, Mg: 0.55 mass%, Ni: 0.25 mass%, Al: 84.70 mass%, unavoidable impurities A cast material 1 was obtained in the same manner as in Example 1 except that a molten aluminum alloy containing H was used.

Comparative Example 1
As a molten aluminum alloy, Si: 11.2 mass%, Cu: 4.50 mass%, Mg: 0.55 mass%, Ni: 0.18 mass%, Al: 83.57 mass%, unavoidable impurities A cast material was obtained in the same manner as Example 1, except that a molten aluminum alloy containing H was used.

Comparative Example 2
As a molten aluminum alloy, Ce: 6.0% by mass, Cu: 4.50% by mass, Mg: 0.55% by mass, Ni: 0.16% by mass, Al: 88.79% by mass, unavoidable impurities A cast material was obtained in the same manner as Example 1, except that a molten aluminum alloy containing H was used.

Comparative Example 3
As a molten aluminum alloy, Ce: 16.0 mass%, Cu: 4.50 mass%, Mg: 0.55 mass%, Ni: 0.16 mass%, Al: 78.79 mass%, unavoidable impurities A cast material was obtained in the same manner as Example 1, except that a molten aluminum alloy containing H was used.

Comparative Example 4
As a molten aluminum alloy, Ce: 10.0 mass%, Cu: 0.10 mass%, Mg: 0.55 mass%, Ni: 0.16 mass%, Al: 89.19 mass%, unavoidable impurities A cast material was obtained in the same manner as Example 1, except that a molten aluminum alloy containing H was used.

Comparative Example 5
As a molten aluminum alloy, Ce: 10.0 mass%, Cu: 12.00 mass%, Mg: 0.55 mass%, Ni: 0.16 mass%, Al: 77.29 mass%, unavoidable impurities A cast material was obtained in the same manner as Example 1, except that a molten aluminum alloy containing H was used.

Comparative Example 6
As molten aluminum alloy, an aluminum alloy melt containing Ce: 10.0 mass%, Cu: 4.50 mass%, Ni: 0.16 mass%, Al: 85.34 mass% and containing unavoidable impurities is used. A cast material was obtained in the same manner as in Example 1 except for the above.

Comparative Example 7
As a molten aluminum alloy, Ce: 10.0 mass%, Cu: 4.50 mass%, Mg: 4.00 mass%, Ni: 0.16 mass%, Al: 81.34 mass%, unavoidable impurities A cast material was obtained in the same manner as Example 1, except that a molten aluminum alloy containing H was used.

Comparative Example 8
As a molten aluminum alloy, Ce: 10.0 mass%, Cu: 4.50 mass%, Mg: 0.55 mass%, Ni: 0.35 mass%, Al: 84.60 mass%, unavoidable impurities A cast material was obtained in the same manner as Example 1, except that a molten aluminum alloy containing H was used.

  Various evaluations were performed based on the following evaluation methods for each cast material obtained as described above. These results are shown in Tables 1 and 2. In Tables 1 and 2, the (A / B) value is a value obtained by dividing “tensile strength A (MPa) at 150 ° C.” by “tensile strength B (MPa) at normal temperature”. Moreover, in each element column in Tables 1-2, the description of "-" has shown that it is a numerical value below a detection limit (0.005 mass%) (that is, the said element was not detected).

<Evaluation method of tensile strength at normal temperature>
A part of the obtained aluminum alloy cast material (cylindrical body) is cut out to prepare a JIS No. 4 test piece, and the measurement environment of a normal temperature (25 ° C.) of the test piece in accordance with the provisions of JIS Z2241-2011. The tensile strength (MPa) at normal temperature was measured by conducting a tensile test below.

<Evaluation method of tensile strength at 150 ° C>
A part of the obtained aluminum alloy cast material (cylindrical body) is cut out to prepare a JIS No. 4 test piece, and after maintaining the test piece at 150 ° C. for 100 hours in accordance with the provisions of JIS Z2241-2011. The tensile strength (MPa) at 150 was measured by conducting a tensile test in a measuring environment of 150 ° C.

<Evaluation method of tensile strength at 200 ° C>
A part of the obtained aluminum alloy cast material (cylindrical body) is cut out to prepare a JIS No. 4 test piece, and after keeping the test piece at 200 ° C. for 100 hours in accordance with the provisions of JIS Z2241-2011. The tensile strength (MPa) at 200 was measured by conducting a tensile test in a measuring environment of 150 ° C.

<Evaluation method of growth rate>
A part of the obtained aluminum alloy cast material (cylindrical body) is cut out to prepare a JIS No. 4 test piece, and the measurement environment of a normal temperature (25 ° C.) of the test piece in accordance with the provisions of JIS Z2241-2011. When a tensile test is performed below and the distance between control points before the tensile test of the tensile test piece is "L ₀ " and the distance between control marks after breaking by the tensile test (immediately before breaking) is "L",
Elongation rate (%) = {(L-L ₀ ) / L ₀ } × 100
The value obtained by the above formula was taken as the elongation rate (%).

<Overall evaluation>
Assuming that the tensile strength at 150 ° C. of the casted aluminum alloy is “A” (MPa), the tensile strength at room temperature of the casted aluminum alloy is “B” (MPa), and the (A / B) value is obtained.
(Judgment criteria)
“◎”: 0.985 <A / B <1.015
“O”: 0.95 <A / B ≦ 0.985, or 1.015 ≦ A / B <1.05
“×”... A / B ≦ 0.95 or 1.05 ≦ A / B
An overall evaluation was made based on the above criteria.

  As apparent from the table, the casted aluminum alloy (aluminum alloy material) of Examples 1 to 10 according to the present invention has high temperature from normal temperature range to 150 ° C. with little or no decrease in tensile strength at 150 ° C. An almost constant, stable and sufficient strength is secured to the region. Therefore, based on the evaluation result of the normal temperature strength of the aluminum alloy material of the present invention, quality assurance of strength at high temperatures up to 150 ° C. is also possible.

  On the other hand, in the aluminum alloy cast materials of Comparative Examples 1, 2, 4, and 6 of the alloy composition deviating from the specified range of the present invention, the reduction in tensile strength at 150 ° C. is considerable compared to the tensile strength at normal temperature. It was a big one. Further, in Comparative Examples 3, 5, 7 and 8 of alloy compositions deviating from the specified range of the present invention, the toughness is lowered due to excessive amounts of Ce, Cu, Mg and Ni, respectively, and the workability is lowered, and the solution treatment is performed. There was a problem that cracking occurred in the cast material at the time of subsequent quenching, so these were not used for the above-mentioned various evaluations (see Table 2).

  The aluminum alloy material according to the present invention is, for example, an aluminum alloy material (raw form) for manufacturing parts for internal combustion engines (for example, piston etc.) and compressor parts (for example compressor wheel etc.) used for automobiles and other various transport devices. Materials, but is not particularly limited to such applications.

1 ... Aluminum alloy products

Claims (6)

  Ce: 7.0% by mass to 15.0% by mass, Cu: 0.5% by mass to 10.0% by mass, Mg: 0.2% by mass to 3.0% by mass, and the Ni content is The aluminum alloy material which is 0.3 mass% or less, and remainder becomes from Al and an unavoidable impurity.   Assuming that the tensile strength at 150 ° C. of the aluminum alloy material is “A” (MPa) and the normal temperature tensile strength of the aluminum alloy material is “B” (MPa), 0.95 <A / B <1.05 The aluminum alloy material according to claim 1, which is   The aluminum alloy is one or more selected from the group consisting of Fe, Mn, Sn, Sc, Ti, Zr, W, Cr, Co, Mo, Ag, Ta, Hf, Nb and Sr. The aluminum alloy material according to claim 1 or 2, containing 0.01% by mass to 5.0% by mass of each of the metals listed above. Ce: 7.0% by mass to 15.0% by mass, Cu: 0.5% by mass to 10.0% by mass, Mg: 0.2% by mass to 3.0% by mass, and the Ni content is A molten metal forming step of obtaining a molten metal of an aluminum alloy having 0.3 mass% or less and the balance being Al and unavoidable impurities;
A casting process for obtaining a cast material by casting the obtained molten metal, and a method of producing an aluminum alloy product.   Assuming that the tensile strength at 150 ° C. of the obtained cast material is “A” (MPa) and the normal temperature tensile strength of the cast material is “B” (MPa), 0.95 <A / B <1. The method for producing an aluminum alloy product according to claim 4, which is 05.   The aluminum alloy molten metal is further selected from the group consisting of Fe, Mn, Sn, Sc, Ti, Zr, V, W, Cr, Co, Mo, Ag, Ta, Hf, Nb and Sr. The method for producing an aluminum alloy product according to claim 4 or 5, wherein each of the above metals is contained in 0.01% by mass to 5.0% by mass.

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