泡沫铝夹芯三明治结构制备及可靠性评价.pdf

硕士学位论文硕士学位论文 泡沫铝夹芯三明治结构制备 及可靠性评价 PREPARATION AND RELIABILITY EVALUTION OF THE ALUMINUM FOAM SANDWICH 于冲冲于冲冲 2012 年年 7 月月 图书分类号： TG457.1 学校代码： 10213 国际图书分类号：621.791 密级：公开 工学硕士学位论文 泡沫铝夹芯三明治结构制备 及可靠性评价 硕 士 研 究 生 ：于冲冲 导 师 ：耿正 教授 申 请 学 位 ：工学硕士 学 科 ：材料加工工程 所 在 单 位 ：材料科学与工程学院 答 辩 日 期 ：2012 年 7 月 授予学位 单 位 ：哈尔滨工业大学 Classified Index: TG457.1 U. D. C: 621.791 Dissertation for the Master Degree in Engineering PREPARATION AND RELIABILITY EVALUTION OF THE ALUMINUM FOAM SANDWICH Candidate: Yu Chongchong Supervisor: Proffessor Geng zheng Academic Degree Applied for: Master of Engineering Speciality: Material Processing Engineering Affiliation: School of Materials Science and Engineering. Date of Defence July, 2012 Degree-Conferring-Institution: Harbin Institute of Technology 哈尔滨工业大学工学硕士学位论文 -I- 摘 要 以泡沫铝为芯层，金属为面板的泡沫铝夹芯三明治结构复合板，是一种新型结构材料，具有一系列的优异性能，在汽车、航空航天与建筑等多个领域得到了广泛应用。

但是应用的基础是实现泡沫铝与金属面板的有效连接，而表面的多孔性及氧化膜使得泡沫铝连接困难针对这个问题，本文提出了 Zn-Al-Cu基合金为钎料，刮擦振动钎焊的方法，制备出了连接良好的夹芯结构板，并对其进行了压缩、弯曲和冲击等性能的测试与分析 刮擦振动钎焊的方法，就是用火焰加热待焊端面，熔敷钎料，同时机械刮擦；冷却，将泡沫铝与上下两个面板同时对接，进行二次加热；再次冷却过程中施加振动作用，完全冷却后即得到了夹芯结构板再次冷却阶段，不施加振动、施加机械振动及超声振动所得到的连接界面有所不同 机械刮擦能去除表面的氧化膜，形成毛细通道，使润湿铺展顺利进行制备的夹芯三明治板，其铝板与泡沫铝的连接处，钎料与铝板结合致密，仅与泡沫铝的孔壁端面结合；再次冷却阶段无振动作用时，钎料未进入泡沫铝的孔隙中；机械振动时，钎料流布并填充进入孔隙中但填充不均匀；超声振动时，钎料流布并填充进入孔隙且填充均匀 制得夹芯结构板的连接处， 钎料/铝板及钎料/泡沫铝孔壁端面结合处的组织由四个相区组成，而中心钎料处由三个相区组成冷却阶段施加不同作用得到的界面组织相似，相的成分有所不同拉剪试验表明，泡沫铝与铝板结合良好 泡沫铝与制备的夹芯结构板，压缩试验对应的应力－应变曲线都可分为三个阶段：弹性阶段、应力平台阶段和密实化阶段；吸能－应变曲线的斜率逐渐增大，表明吸能效率增大。

夹芯结构板的三点弯曲试验，应力－应变曲线也由三个阶段组成，可由面板局部屈曲、芯体剪切失效和面板的凹陷及芯层密实的变化过程来解释在三点弯曲与落锤冲击的试验中，夹芯结构板都表现出了比泡沫铝更为优异的性能，强度与能量吸收为泡沫铝的几倍甚至几十倍；试验后，夹芯结构整体未断裂，芯层破坏严重，界面连接依然良好 钎料在泡沫铝等多孔材料表面的润湿行为，受表面状态、钎料成分、孔隙率等因素的影响对 Zn-Al-Cu 基合金在泡沫铝表面的润湿，可以建立倒“凹”状的润湿模型，并进行初步的推导计算 关键词：夹芯三明治板；刮擦振动钎焊；界面组织；力学性能；润湿模型 哈尔滨工业大学工学硕士学位论文 -II- Abstract Aluminum Foam Sandwich, with foam aluminum as the core layer, metal for the panel, is a new type of structural materials, which has a series of excellent performance, in the automotive, aerospace and construction and other fields has been widely applied. The foundation of the application is the realization of effective connection between foam aluminum and metal plate, but the surface porous and oxidation film makes foam aluminum connection problems. Aiming at this problem, this paper puts forward the scratching and vibration auxiliary brazing method, with Zn-Al-Cu alloy for solder. Then using the above methods, prepared the sandwich structure well connected, and has carried on these compressive, bending and impact performance test and analysis . Scratching and vibration auxiliary soldering, the specific process as follows: heat the mother material surface by flame, melt the solder and scratch at the same time; after cooling, dock the aluminum foams and two aluminum panel up and down, then secondary heating; the secondary cooling is applied in the process of vibration effect, completely after cooling to obtain structural sandwich panel. In the second cooling stage, without vibration effect, putting on mechanical vibration and the ultrasonic vibration is applied to get connection interfaces of different structural sandwich panel. Mechanical scraping, contribute to the removal of the surface oxide film, forming a capillary channel, so that the wetting and spreading smoothly. Joint between aluminum sheet and aluminum foam, solder combine with aluminum sheet tight, only connect with the aluminum foam hole wall surface. The second cooling stage without vibration, solder fill into the aluminum foam pore; putting on mechanical vibration, solder flow and fill into the pores but fill uneven; ultrasonic vibration, solder flow and filled into the pores and uniform filling. The joint of prepared sandwich plate, solder/aluminum and solder/aluminum foam hole wall surface combination formed the microstructure organization by four phase composition, while the center solder by three phase composition. The second cooling stage exert different effects are similar to the interface microstructure, phase composition of different. Tensile shear test results show that the aluminum sheet well connect with aluminum foam from the beginning to the end. Aluminum foam and the prepared sandwich structure plate, the stress strain curve corresponding to compression tests can be divided into three stages: elastic, stress platform and densification stage; slope of the energy absorbing strain curve increases gradually, show that the energy absorption efficiency raise. The prepared 哈尔滨工业大学工学硕士学位论文 -III- sandwich panel of three point bending test, stress-strain curve is composed of three stages, which consists of a panel of local buckling, core shear failure and panel depressions and core layer compacting process to explain. In three point bending and impact test, the sandwich panel show than the aluminum foam is more excellent performance, strength and energy absorption of foam。