Method for preparing high strength and high plasticity aluminum-magnesium alloy of mixcrystal structure

Abstract

The invention relates to a method for preparing high strength and high plasticity aluminum-magnesium alloy of a mixcrystal structure. The preparing method includes the two steps of homogenizing treatment and intermediate annealing-assisted large reduction controlled rolling. The method specially comprises the steps that element macro segregation in a cast-state structure is removed through high-temperature homogenizing treatment at first to achieve high alloying element solubility; and then controlled rolling deformation is combined with intermediate annealing treatment to introduce high-density dislocation, and recrystallization is promoted to refine crystal grains. Nano-grains, ultra-fine grains and micro-grains in the aluminum-magnesium alloy structure prepared through the method are mixed to coexist, and compared with a single nano-grain or ultra-fine grain structure, the mixcrystal structure aluminum-magnesium alloy has high strength and high plasticity. Dislocation motion, accumulation and storage in the plastic deformation process can be facilitated through the mixcrystal structure, plastic strain local concentration of a nano-grain metal material is effectively prevented, and work hardening and plastic deformability of the material can be improved obviously.

Description

technical field

[0001] The invention relates to the field of metal materials, in particular to a preparation method of a high-strength plastic mixed crystal structure aluminum-magnesium alloy. Background technique

[0002] Aluminum-magnesium alloy has low density, high specific strength, good processing performance, corrosion resistance, welding performance and fatigue resistance, and low price. High-strength aluminum-magnesium alloys have become popular candidates for replacing traditional steel parts, and have broad application prospects in aerospace, transportation, and building structures. However, the strength of traditional wrought aluminum-magnesium alloys is difficult to match that of steel. The strength of aluminum-magnesium alloys can be greatly improved by using large deformation technology, which has attracted extensive attention in recent years. At present, the preparation methods of high-strength non-heat-treated aluminum-magnesium alloys mainly include high-...

Examples

Embodiment 1

[0020] (1) High-temperature homogenization treatment: The cast Al-5Mg alloy is subjected to a homogenization heat treatment at 580 degrees Celsius for 180 minutes to eliminate macro-segregation of elements in the as-cast structure and achieve high solid solution of alloying elements;

[0021] (2) Intermediate annealing assisted large-reduction controlled rolling: process the Al-5Mg alloy after homogeneous heat treatment into a sample of a certain size, and then carry out rolling deformation with a single-pass reduction of 60%. No microcracks occur; place the deformed sample in an air heating furnace or a salt bath furnace, and keep it warm at 320 degrees Celsius for 10 minutes to eliminate internal stress and form a recovered or recrystallized structure, and then put the sample in cold water to cool down to room temperature; The annealed sample was subjected to rolling deformation with a reduction of 70% at room temperature, that is, the total reduction reached 88%, and no obvi...

Embodiment 2

[0024] (1) High-temperature homogenization treatment: The cast Al-7Mg alloy is subjected to a homogenization heat treatment at 550 degrees Celsius for 180 minutes to eliminate macro-segregation of elements in the as-cast structure and achieve high solid solution of alloying elements;

[0025] (2) Intermediate annealing assisted large-reduction controlled rolling: process the Al-7Mg alloy after homogeneous heat treatment into a sample of a certain size, and then carry out rolling deformation with a single-pass reduction of 70%. No micro-cracks are produced; place the deformed sample in an air heating furnace or a salt bath furnace, and keep it warm at 350 degrees Celsius for 5 minutes to eliminate internal stress and form a recovered or recrystallized structure, and then put the sample in cold water and cool it down to room temperature; The annealed sample was subjected to rolling deformation with a reduction of 70% at room temperature, that is, the total reduction reached 91%, ...

Embodiment 3

[0028] (1) High-temperature homogenization treatment: The cast Al-7Mg-0.2Sc alloy ingot is subjected to a homogenization heat treatment at 550 degrees Celsius for 180 minutes to eliminate macro-segregation of elements in the as-cast structure and achieve high solid solution of alloying elements;

[0029] (2) Intermediate annealing assisted large-reduction controlled rolling: the Al-7Mg-0.2Sc alloy after homogeneous heat treatment was processed into a rolling sample of a certain size, and then rolled and deformed in two passes. The lower weight is 50%, and no microcracks are produced on the sample surface; the rolled sample is placed in an air heating furnace or a salt bath furnace, and is kept at 350 degrees Celsius for 10 minutes to eliminate internal stress, and then the sample is put into cold water to Room temperature; the sample after intermediate annealing is subjected to rolling deformation at room temperature with a reduction of 60% in a single pass, that is, the total ...

technical field

[0001] The invention relates to the field of metal materials, in particular to a preparation method of a high-strength plastic mixed crystal structure aluminum-magnesium alloy. Background technique

[0002] Aluminum-magnesium alloy has low density, high specific strength, good processing performance, corrosion resistance, welding performance and fatigue resistance, and low price. High-strength aluminum-magnesium alloys have become popular candidates for replacing traditional steel parts, and have broad application prospects in aerospace, transportation, and building structures. However, the strength of traditional wrought aluminum-magnesium alloys is difficult to match that of steel. The strength of aluminum-magnesium alloys can be greatly improved by using large deformation technology, which has attracted extensive attention in recent years. At present, the preparation methods of high-strength non-heat-treated aluminum-magnesium alloys mainly include high-...

Examples

Embodiment 1

[0020] (1) High-temperature homogenization treatment: The cast Al-5Mg alloy is subjected to a homogenization heat treatment at 580 degrees Celsius for 180 minutes to eliminate macro-segregation of elements in the as-cast structure and achieve high solid solution of alloying elements;

[0021] (2) Intermediate annealing assisted large-reduction controlled rolling: process the Al-5Mg alloy after homogeneous heat treatment into a sample of a certain size, and then carry out rolling deformation with a single-pass reduction of 60%. No microcracks occur; place the deformed sample in an air heating furnace or a salt bath furnace, and keep it warm at 320 degrees Celsius for 10 minutes to eliminate internal stress and form a recovered or recrystallized structure, and then put the sample in cold water to cool down to room temperature; The annealed sample was subjected to rolling deformation with a reduction of 70% at room temperature, that is, the total reduction reached 88%, and no obvi...

Embodiment 2

[0024] (1) High-temperature homogenization treatment: The cast Al-7Mg alloy is subjected to a homogenization heat treatment at 550 degrees Celsius for 180 minutes to eliminate macro-segregation of elements in the as-cast structure and achieve high solid solution of alloying elements;

[0025] (2) Intermediate annealing assisted large-reduction controlled rolling: process the Al-7Mg alloy after homogeneous heat treatment into a sample of a certain size, and then carry out rolling deformation with a single-pass reduction of 70%. No micro-cracks are produced; place the deformed sample in an air heating furnace or a salt bath furnace, and keep it warm at 350 degrees Celsius for 5 minutes to eliminate internal stress and form a recovered or recrystallized structure, and then put the sample in cold water and cool it down to room temperature; The annealed sample was subjected to rolling deformation with a reduction of 70% at room temperature, that is, the total reduction reached 91%, ...

Embodiment 3

[0028] (1) High-temperature homogenization treatment: The cast Al-7Mg-0.2Sc alloy ingot is subjected to a homogenization heat treatment at 550 degrees Celsius for 180 minutes to eliminate macro-segregation of elements in the as-cast structure and achieve high solid solution of alloying elements;

[0029] (2) Intermediate annealing assisted large-reduction controlled rolling: the Al-7Mg-0.2Sc alloy after homogeneous heat treatment was processed into a rolling sample of a certain size, and then rolled and deformed in two passes. The lower weight is 50%, and no microcracks are produced on the sample surface; the rolled sample is placed in an air heating furnace or a salt bath furnace, and is kept at 350 degrees Celsius for 10 minutes to eliminate internal stress, and then the sample is put into cold water to Room temperature; the sample after intermediate annealing is subjected to rolling deformation at room temperature with a reduction of 60% in a single pass, that is, the total ...

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