摘要
铝合金液冷板是航空航天、国防等领域电子设备的重要散热零件,一般具有微细流道和复杂的外形,非常适合采用激光选区熔化(SLM)增材制造技术整体成形。为提升液冷板的整体成形效率,研究了1 kW高功率激光SLM成形铝合金的致密化行为、显微结构、力学性能以及微孔的最小孔径。结果表明:随着激光体能量密度增加,SLM成形AlSi10Mg试样的致密度先提升后趋于稳定;成形高致密(致密度>99.5%)试样所需的激光体能量密度为47.6~200 J/mm^(3);成形试样的显微组织由总体上呈〈100〉择优取向的α-Al基体和网状共晶Si组成;在晶界强化、固溶强化和第二相强化的共同作用下,成形试样的抗拉强度、屈服强度、延伸率分别达到(433±10)MPa、(267±8)MPa、(5.5±0.5)%,均超过同牌号压铸件;在高功率SLM成形条件下,水平与竖直伸展微孔的最小孔径分别为0.6 mm和0.4 mm,可以满足大部分微细流道的设计与成形需求。依托基础工艺研究,本文利用高功率SLM技术实现了液冷板局部模拟样件的快速成形,成形效率可达到75.6 cm^(3)/h。
Aluminum alloy liquid cold plates are important parts of heat dissipation for the electronic equipments used in aerospace and national defense industries. Usually they have complex outlines and microchannels;thus, they are suitable to be fabricated via selective laser melting(SLM) additive manufacturing technology. To elevate the build rate of the SLM-processed liquid cold plates, a high-power(1 kW) SLM apparatus was used to process AlSi10Mg alloy in this study, and the densification behavior, microstructure, mechanical properties, and minimum hole diameter of the SLM-processed samples were investigated. Results show that the relative density of the highpower SLM-processed samples first increase with the increase in laser volume energy density, and then remain unchanged at high laser volume energy densities. To obtain a high relative density of more than 99. 5%, the laser volume energy density should be set in the range of 47. 6-200 J/mm^(3) during the high-power SLM process. The microstructure of the as-fabricated sample comprises α-Al cellular dendritic matrix possessing a 〈100〉 texture along the building direction and reticular eutectic Si. Owing to the comprehensive effects of grain boundary, solid solution, and second phase strengthening, the tensile strength, yield strength, and elongation of the high-power SLM-processed samples were(433±10) MPa,(267±8) MPa, and(5. 5±0. 5)%, respectively, which were higher than the corresponding values of the die casting AlSi10Mg. When the 1 kW high-power laser was used in the SLM process of AlSi10Mg, the minimum horizontal and vertical hole diameters that could be fabricated were 0.6 mm and 0.4 mm, respectively, which could satisfy almost all design and forming requirements for a liquid cold plate. Based on the above technology, local simulation parts of an aluminum alloy liquid cold plate were successfully fabricated using high-power SLM, and the build rate was up to 75. 6 cm^(3)/h.
作者
刘梦娜
魏恺文
邓金凤
黄高
钟桥
曾晓雁
Liu Mengna;Wei Kaiwen;Deng Jinfeng;Huang Gao;Zhong Qiao;Zeng Xiaoyan(Wuhan National Laboratory for Optoelectronics,Huazhong University of Science and Technology,Wuhan,Hubei 430074,China)
出处
《激光与光电子学进展》
CSCD
北大核心
2021年第13期348-357,共10页
Laser & Optoelectronics Progress
关键词
激光技术
激光选区熔化
铝合金液冷板
成形效率
显微组织
力学性能
最小孔径
laser technique
selective laser melting
aluminum alloy liquid cold plate
build rate
microstructure
mechanical properties
minimum hole diameter
