Search

CN-122013007-A - High-strength heat-resistant AlCuMn aluminum alloy material and heat treatment method thereof

CN122013007ACN 122013007 ACN122013007 ACN 122013007ACN-122013007-A

Abstract

The invention discloses a high-strength heat-resistant AlCuMn aluminum alloy material and a heat treatment method thereof. The heat treatment method not only can remarkably improve the high-temperature strength of the Al-Cu-Mn aluminum alloy, but also has the advantages of simple heat treatment process, low cost and easy popularization.

Inventors

  • SU XIANG
  • BU CHUNCHENG
  • QI XING
  • ZHU YONGJIE
  • SUN YAO
  • PENG QICHENG
  • SHEN YANG
  • WANG MINZHI

Assignees

  • 常州工学院

Dates

Publication Date
20260512
Application Date
20260123

Claims (10)

  1. 1. The heat treatment method of the high-strength heat-resistant AlCuMn aluminum alloy material is characterized by comprising the following steps of: The first step, designing an alloy component, namely an Al-Cu-Mn aluminum alloy material, wherein the weight percentage expression of the alloy element is Al a Cu b Mn c , a is more than or equal to 88.0 and less than or equal to 98.5,1 and less than or equal to b and less than or equal to 8, c is more than or equal to 0.5 and less than or equal to 4, and a+b+c=100; Secondly, smelting in inert atmosphere after batching to obtain alloy materials; Thirdly, carrying out solution treatment, namely preserving the heat of the alloy material at 538-543 ℃ for 0.5-5 hours, and then quenching the alloy material into 50-100 ℃ water; Fourthly, performing low-temperature aging treatment, namely preserving the temperature of the alloy material at 160-175 ℃ for 0.5-5 hours, and then performing air cooling; and fifthly, performing high-temperature aging treatment, namely preserving the temperature of the alloy material at 230-300 ℃ for 1-100 hours, and then performing air cooling.
  2. 2. The method of claim 1, wherein in the first step, a ternary Al-Cu-Mn alloy phase diagram under near equilibrium solidification conditions is calculated by using Thermal-Calc software to obtain an alloy component of an alpha-Al+theta-Al 2 Cu+T-A1 20 Cu 2 Mn 3 three-phase region, wherein in order to avoid continuous precipitation of theta and T phases at a grain boundary, the mole percentage of the theta and T phases is 3% -24% (theta+T) Mole fraction % -24%, and the expression of the weight percentage of the alloy element is Al a Cu b Mn c , wherein a is 88.0% -98.5,1% -8 b, c is 0.5% -4, and a+b+c=100.
  3. 3. The method of claim 1, wherein the alloy element weight percent is expressed as Al a Cu b Mn c , wherein 88.0≤a≤ 94,5≤b≤8, 1≤c≤4, and a+b+c=100.
  4. 4. The method of claim 1, wherein in the third step, the alloy material is incubated at 540 ℃ for 1-2 hours and quenched into 50 ℃ water.
  5. 5. The method according to claim 1, wherein in the fourth step, the alloy material is kept at 170 ℃ for 1 to 3 hours and then air-cooled.
  6. 6. The method according to claim 1, wherein in the fifth step, the alloy material is kept at 250 ℃ to 260 ℃ for 5 to 10 hours and then air-cooled.
  7. 7. The method according to claim 1, wherein in the third to fifth steps, the alloy ingot is charged into a corundum crucible, and the alloy material is subjected to solution treatment, low-temperature aging treatment and high-temperature aging treatment by using a resistance furnace, wherein the temperature control accuracy of the resistance furnace is + -1 ℃.
  8. 8. The high-strength heat-resistant AlCuMn aluminum alloy material prepared by the heat treatment method according to any one of claims 1 to 7.
  9. 9. The high-strength heat-resistant AlCuMn aluminum alloy material as claimed in claim 8, wherein the nano-phase characteristic structure of the alloy material is characterized in that a Mn-rich theta' -Al 2 Cu phase is of a long needle shape, the length is 300-400 nm, the thickness is 10-20 nm, the number density is 0.1X10 21 ~1×10 21 m -3 ;T-A1 20 Cu 2 Mn 3 phase is of a thick rod shape, the length is 350-370 nm, the thickness is 110-135 nm, and the number density is 2.5X10 19 ~5×10 19 m -3 .
  10. 10. The high-strength heat-resistant AlCuMn aluminum alloy material as claimed in claim 8, wherein the tensile strength of the alloy material at 360 ℃ reaches 105-148 mpa.

Description

High-strength heat-resistant AlCuMn aluminum alloy material and heat treatment method thereof Technical Field The invention belongs to the technology of Al-Cu-Mn aluminum alloy materials, in particular to a high-strength heat-resistant Al-Cu-Mn aluminum alloy material and a heat treatment method thereof. Background In view of the serious challenges of resources, energy and environment, the high-end manufacturing industries of airplanes, new energy automobiles and the like need for lightweight structural members. The aluminum alloy has the excellent characteristics of small density, high strength, good processability, corrosion resistance and the like, and is widely applied to the fields of aerospace, building bridges, automobiles, ships, mechanical equipment and the like as an excellent structural material. The Al-Cu-Mn aluminum alloy has excellent high-temperature oxidation resistance and good plastic deformation resistance under the long-time actions of temperature and dynamic and static loads, and is widely applied to important bearing parts such as aerospace, weapons, automobiles and ships, in particular aircraft skins, missile shells, aeroengine cylinders, blades, cases and the like. With the rapid development of aerospace and weapon equipment, higher requirements are put forward on the high-temperature performance of aluminum alloy, however, performance indexes such as thermal fatigue, high-temperature strength and the like of the active heat-resistant aluminum alloy are close to the limit, and the requirement of equipment development is difficult to meet. The Al-Cu-Mn aluminum alloy has the yield strength of less than 100MPa at 350 ℃ and limits the high-temperature application. The main strengthening phases in the aluminum alloy are a theta-Al 2 Cu phase and a T-A1 20Cu2Mn3 phase, wherein the heat stability temperature of the theta phase is about 225 ℃, and the heat stability temperature of the T phase is about 350 ℃. The existing researches generally develop a heat treatment process research aiming at theta phase, and literature 1（Aging behavior and strengthening mechanisms of coarsening resistant metastable θ' precipitates in an Al-Cu alloy, Materials and Design 2021, 198:109378）, adopts a T6 heat treatment (solid solution and peak aging) process to realize precipitation of a large amount of dispersed nano theta' phase in crystal grains, wherein the nano phase can effectively pin dislocation so as to obtain excellent room temperature strength. Because the thermal stability temperature of the theta 'phase is lower, the material is exposed for a long time at high temperature (more than or equal to 250 ℃), the semi-coherent theta' phase is transformed to the non-coherent theta phase, and meanwhile, the phenomena of coarsening, spheroidization, dissolution and the like of the theta phase occur, so that the strengthening effect is reduced, and the high-temperature strength of the material is sharply reduced. Document 2 (a heat treatment method for improving the high-temperature strength of an Al-Cu-Mn-Zr-based aluminum alloy), ZL202310081184.8, adopts a solution treatment, primary aging treatment and secondary aging treatment process to obtain a multi-stage strengthening phase microstructure structure, namely a large number of dispersed coarse rod-shaped T-phases, long needle-shaped theta phases and spherical particle Al 3 Zr phases, and utilizes Zr element meta-aggregation retardation theta' phase transformation and coarsening, spheroidization and dissolution of the theta phases to improve the high-temperature strength of the material. However, under the loading condition at high temperature and long time, the aggregated Zr element at the interface of the nano theta 'and theta phase can react with the Al element to form Al 3 Zr phase, the diffusion of Cu element can not be continuously hindered, so that the theta' phase and the theta phase are instable to generate actions such as transformation, coarsening, spheroidization, dissolution and the like, and the high-temperature strength of the material is reduced. Therefore, the existing heat treatment scheme of the Al-Cu-Mn aluminum alloy is not applicable to the high-temperature long-term service condition. Disclosure of Invention The invention aims to provide a high-strength heat-resistant Al-Cu-Mn aluminum alloy material and a heat treatment method thereof. The heat treatment method not only can remarkably improve the high-temperature strength of the Al-Cu-Mn aluminum alloy, but also has the advantages of simple heat treatment process, low cost and easy popularization. In order to achieve the above object, the present invention provides a heat treatment method of a high-strength heat-resistant AlCuMn aluminum alloy material, the method comprising the steps of: The first step, designing an alloy component, namely an Al-Cu-Mn aluminum alloy material, wherein the weight percentage expression of the alloy element is Al aCubMnc, a is more than or equal to 8