回复与再结晶退火
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第三章 基于回复与再结晶过程的退火 Annealing Based on
Recovery and Recrystallization
4. 1 概述
(1) 对象:冷变形或有严重内应力的金属及其合金 (2) 目的:
➢提高塑性,降低变形抗力,有利于变形材料继续的后续加工 ➢有利于加工制品的最终使用性能
✓退火去内应力; ✓制造强度和塑性配合良好的半硬制品; ✓提高弹性极限(铜合金的低温退火硬化现象); ✓提高耐蚀性和组织稳定性。
1. A large reduction in the number of point defects; 2. Dislocations of opposite sign attract and/or
annihilate each other; 3. Dislocations rearrange themselves into 4. lower energy configuration. 4. Both point defects and dislocations are absorbed 5. by grain boundaries migrating through the material; 5. A reduction in the grain boundary area.
结构、成分的改变,仅伴随 着缺陷运动与消失,是一种 组织变化。
晶粒长大:晶粒以小吃大,
即界面能下降的过程。
Ag deformed 50% and annealed at 300C for 30S. Longitudinal
Summary: Upon annealing after cold deformation,
在加热退火过程中组织变化:
冷变形储能使冷变形金属的自由能提高,这是加热过程中组织变化的驱动力。经回 复、再结晶、晶粒长大等过程,完全再结晶的金属组织和性能恢复到平衡态。不完 全的可能停留在中间阶段。
加热时的转变过程:
回复:储能降低,能量再
分配, 主要是空位、位错 等运动、重布的过程。
再结晶:储能差消失,无
(3) 原因:
随着冷变形程度增大,加工硬化,变形抗力增大,塑性降低;
变形不均,导致内应力产生。
(4) 退火过程中主要固态转变: Example:
回复、再结晶与晶粒长大
1ຫໍສະໝຸດ Baidu A steel wire cold bended;
2. Al-, Cu-alloys plate---annealed
4. 2 冷变形金属在加热退火过程中组织性能变化
Al with high purity hot compressed (strain of 0.3). Polycrystal specimen.
Al with high purity hot compressed (strain of 1.5). Polycrystal specimen.
Large-grained materials
Optical micrograph of the as-cast AA5754 alloy cold rolled to 95% reduction showing the alignment of particles and particle clusters (arrows) on the longitudinal plane along the rolling direction.
金属冷变形所消耗的变形功大部分(90~98%)以热的形式耗散,小部 分(2~10%)以储能的形式残留,存在金属内部。储能的结构形式是 晶格畸变和各种晶体缺陷(如点缺陷、位错、亚晶界、堆垛层错等)
冷变形金属
(1)纤维组织 (2)变形织构 (3)晶格畸变(储能) (4)晶体缺陷(储能)——点 缺陷、位错、亚晶界、堆垛 层错等以及位错缠结、位错 网胞等亚结构
Fig.? TEM micrograph showing a tendency of cell formation of the AA5182 stressed to 2.4.
Metal with lower energy of stacking fault:
Early stages of recrystallization: Observations were carried out on the longitudinal section within the shear band area of a Ag crystal deformed 67% and annealed at 265C for 30S.
EBSD maps showing microstructure development of medium-grained Al-0.1Mg after deformation at strains: (a) 0.69, (b) 1.2, (c) 2.6, (d) 3.9. Comparison with largegrained materials shows that the low angle boundaries are less obviously aligned, and that the formation of new high angle boundaries by process such as deformation banding, is less extensive and tends to occur mainly at the higher strains.
Fig.? SEM backscattered micrographs of large-grained Al-0.1Mg: (a) deformed 50%, showing cell bands aligned at 40o to rolling plane, (b) deformed 70%, showing large scale deformation banding of grain A.
Recovery and Recrystallization
4. 1 概述
(1) 对象:冷变形或有严重内应力的金属及其合金 (2) 目的:
➢提高塑性,降低变形抗力,有利于变形材料继续的后续加工 ➢有利于加工制品的最终使用性能
✓退火去内应力; ✓制造强度和塑性配合良好的半硬制品; ✓提高弹性极限(铜合金的低温退火硬化现象); ✓提高耐蚀性和组织稳定性。
1. A large reduction in the number of point defects; 2. Dislocations of opposite sign attract and/or
annihilate each other; 3. Dislocations rearrange themselves into 4. lower energy configuration. 4. Both point defects and dislocations are absorbed 5. by grain boundaries migrating through the material; 5. A reduction in the grain boundary area.
结构、成分的改变,仅伴随 着缺陷运动与消失,是一种 组织变化。
晶粒长大:晶粒以小吃大,
即界面能下降的过程。
Ag deformed 50% and annealed at 300C for 30S. Longitudinal
Summary: Upon annealing after cold deformation,
在加热退火过程中组织变化:
冷变形储能使冷变形金属的自由能提高,这是加热过程中组织变化的驱动力。经回 复、再结晶、晶粒长大等过程,完全再结晶的金属组织和性能恢复到平衡态。不完 全的可能停留在中间阶段。
加热时的转变过程:
回复:储能降低,能量再
分配, 主要是空位、位错 等运动、重布的过程。
再结晶:储能差消失,无
(3) 原因:
随着冷变形程度增大,加工硬化,变形抗力增大,塑性降低;
变形不均,导致内应力产生。
(4) 退火过程中主要固态转变: Example:
回复、再结晶与晶粒长大
1ຫໍສະໝຸດ Baidu A steel wire cold bended;
2. Al-, Cu-alloys plate---annealed
4. 2 冷变形金属在加热退火过程中组织性能变化
Al with high purity hot compressed (strain of 0.3). Polycrystal specimen.
Al with high purity hot compressed (strain of 1.5). Polycrystal specimen.
Large-grained materials
Optical micrograph of the as-cast AA5754 alloy cold rolled to 95% reduction showing the alignment of particles and particle clusters (arrows) on the longitudinal plane along the rolling direction.
金属冷变形所消耗的变形功大部分(90~98%)以热的形式耗散,小部 分(2~10%)以储能的形式残留,存在金属内部。储能的结构形式是 晶格畸变和各种晶体缺陷(如点缺陷、位错、亚晶界、堆垛层错等)
冷变形金属
(1)纤维组织 (2)变形织构 (3)晶格畸变(储能) (4)晶体缺陷(储能)——点 缺陷、位错、亚晶界、堆垛 层错等以及位错缠结、位错 网胞等亚结构
Fig.? TEM micrograph showing a tendency of cell formation of the AA5182 stressed to 2.4.
Metal with lower energy of stacking fault:
Early stages of recrystallization: Observations were carried out on the longitudinal section within the shear band area of a Ag crystal deformed 67% and annealed at 265C for 30S.
EBSD maps showing microstructure development of medium-grained Al-0.1Mg after deformation at strains: (a) 0.69, (b) 1.2, (c) 2.6, (d) 3.9. Comparison with largegrained materials shows that the low angle boundaries are less obviously aligned, and that the formation of new high angle boundaries by process such as deformation banding, is less extensive and tends to occur mainly at the higher strains.
Fig.? SEM backscattered micrographs of large-grained Al-0.1Mg: (a) deformed 50%, showing cell bands aligned at 40o to rolling plane, (b) deformed 70%, showing large scale deformation banding of grain A.