Solid-state additive manufacturing high performance aluminum alloy 6061 enabled by an in-situ micro-forging assisted cold spray
Solid-state additive manufacturing high performance aluminum alloy 6061 enabled by an in-situ micro-forging assisted cold spray
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DOI：
10.1016/j.msea.2020.139024
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发表时间：
2020-03
期刊：
影响因子：
6.4
通讯作者：
Yingkang Wei;Xiao-Tao Luo;X. Chu;Guosheng Huang;Chang-jiu Li
中科院分区：
文献类型：
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作者：
Yingkang Wei;Xiao-Tao Luo;X. Chu;Guosheng Huang;Chang-jiu Li
冷喷涂是一种具有竞争力的增材制造方法，具有多种独特的特性，可以使用多种材料大规模生产金属部件。在文献中，使用高成本氦气生产的高性能冷喷涂铝沉积物已适合各种应用。在这项研究中，使用低成本氮气通过原位微锻造效应 (MF-CS) 冷喷涂方法生产高性能铝合金 6061 (AA6061) 沉积物。结果表明，MF-CS AA6061 矿床具有非常低的孔隙率以及较高的极限拉伸强度 (UTS) 和弹性模量 (E)。此外，MF-CS AA6061 沉积物由具有随机取向的优质等轴亚微米细 Al 晶粒组成。然而，沉积过程中强烈的颗粒塑性变形引起的严重加工硬化导致 MF-CS AA6061 沉积物的延展性非常低。为了消除这一限制，对 MF-CS AA6061 沉积物进行了三种热处理策略（应力消除、再结晶退火和 T6）。研究发现，热处理对颗粒间结合和颗粒内微观结构（晶粒尺寸、位错密度和析出）产生复杂的影响，并且不同的策略导致AA6061沉积物的机械性能不同。其中，T6 热处理的 AA6061 镀层具有最佳的整体机械性能，具有可比的 UTS 和 E，但延展性仅略逊于相应的 T6 块体。
Cold spraying is a competitive additive manufacturing method featuring several unique characteristics and allows large-scale production of metallic components from a wide range of materials. In literature, high performance cold sprayed aluminum deposits produced using high-cost helium gas have been qualified for various applications. In this study, high performance aluminum alloy 6061 (AA6061) deposits were produced through a cold spray method using low-cost nitrogen gas enabled by an in-situ micro-forging effect (MF-CS). Results show that the MF-CS AA6061 deposit presents very low porosity as well as high ultimate tensile strength (UTS) and elastic modulus (E). Moreover, the MF-CS AA6061 deposit consists of superior equiaxed submicron fine Al grains with random orientations. However, the severe work hardening induced by intensive particle plastic deformation during deposition leads to very low ductility of the MF-CS AA6061 deposit. To eliminate this limitation, three strategies of heat treatments (stress relieving, recrystallization annealing and T6) were performed to the MF-CS AA6061 deposit. It was found that heat treatment generated complex effects on both inter-particle bonding and inner-particle microstructure (grain size, dislocation density and precipitation) and different strategies lead to different mechanical properties of AA6061 deposits. Among them, T6 heat-treated AA6061 deposits give the best overall mechanical properties with comparable UTS and E and only slightly inferior ductility to the corresponding T6 bulk.