monelcu爆炸复合棒的制备及复合过程数值模拟研究.doc

摘 要

用于电子、通讯等军工及民用设备的复合金属材料要求具有高强度、高导热、高密封等性能。为了获得具有较高结合强度的蒙乃尔/铜复合棒，首次采用爆炸复合方法对其进行了制备。本文主要从爆炸复合参数理论、实验分析和数值模拟三个方面对爆炸复合法制备蒙乃尔/铜复合棒进行了研究。得出了如下结论：
1、通过计算机辅助设计程序，对蒙乃尔/铜这种金属组合的爆炸复合参数进行计算，并得出了爆炸复合窗口，从中选择合理的爆炸复合参数。
2、利用爆炸复合方法成功制备了蒙乃尔/铜双金属复合棒材。借助金相显微镜（OM）、扫描电子显微镜（SEM）、能谱分析（EDS）和压剪分离测试，探讨了不同工艺条件下蒙乃尔/铜爆炸复合界面的微观组织和力学性能。结果表明：随着爆炸比的增加，结合界面逐渐由平直状过渡到波状；在铜基体晶粒内的形变孪晶数量随爆炸比的增加而增加；界面局部存在少量熔区，熔区内存在细小的柱状晶；复合界面中没有发生扩散，但经过热处理后其界面观察到了扩散。剪切断裂发生在铜侧而非界面处，表明界面结合强度高于铜基体。结合界面附近的硬度较两侧基体内的硬度为高，并且随着与界面距离的增加，两侧基体内的硬度逐渐降低。
3、采用有限元软件LS-DYNA对爆炸复合过程进行了数值模拟。获得了爆炸复合过程中复层速度、碰撞区域压力和速度分布及其大小，并与理论计算结果和实验结果进行了比较。结果表明，爆炸复合数值模拟结果与理论和实验结果符合良好，所建立的模拟准确可靠，LS-DYNA可较好的模拟了爆炸复合过程，但尚不能对爆炸复合过程中的射流及波形特征进行模拟。通过数值模拟可方便了解爆炸复合过程，为爆炸复合工艺参数的选择提供了参考。

关键词 蒙乃尔/铜，爆炸复合，界面，数值模拟
 
ABSTRACT

Composite metallic material, used in the field of electronical, communicational and other civil equipments, are required to have the properties of high strength, high thermal conductivity and high leak tightness. The high-bonding-strength Monel/Cu clad rod was prepared by means of explosive cladding technology for the first time. The explosive cladding parameters were optimized in light of the related theory and experimental analysis, and the cladding process was numerically simulated in the present work. The conclusions were as follows:
1、By means of computer-aid-design program, the explosive cladding parameters of Monel/Cu system were calculated and the explosive cladding window was obtained, then the optimal parameters were chosen.
2、The Monel/Cu bimetal clad rod was produced with the explosive cladding technique. The microstructure and mechanical properties of the bonding interface in some different processing were analyzed by means of optical microscope, scanning electron microscopy, energy spectrum analysis and shearing separate tests. The results showed that the smooth bonding interface was transformed to a wavy bonding interface as the explosive ratios increased. Deformation twins were observed in the grains of the copper matrix, whose amount increased with the increasing of the explosive ratio. There were a certain amount of molten zones in the interface and fine columnar grains existed in this molten zone. EDS analysis indicated that diffusion did not take place between bond interfaces, however, diffusion was observed after annealing. The shearing fracture took place in the copper matrix and not in the bond interface. The microhardness, in the vicinity of the interface, was higher than that of metal matrix, and gradually decreased away from the interface.
3、Explosive cladding process was numerically simulated through finite element software LS-DYNA. the velocity of clad tube、pressure distribution of collision zone were calculated during the cladding process. Compared with theoretically calculation and experimental results, the numerically simulated results showed that, the numerically simulated results were corresponded to theoretic results and experimental results, the mathematical model can simulate the process of explosive cladding correctly. However, the jet formation and the wavy interface can't be simulated during the explosive cladding process. The numerical simulation can be referred to explosive cladding technology.

KEY WORDS  monel/copper, explosive cladding, interface, numerical simulation
 
目录

摘 要 I
ABSTRACT II
第一章 文献综述 1
1.1 Monel/Cu复合棒材的研究背景 1
1.2双金属复合管/棒的制备方法 1
1.2.1离心技术法 1
1.2.2消失模真空吸铸法 2
1.2.3中频感应加热钎焊法 2
1.2.4拉拔成形法 2
1.2.5滚压成形法 3
1.2.6电磁成形法 3
1.2.7热膨胀法 4
1.2.8填芯连铸复合法 4
1.3爆炸复合双金属复合管/棒 4
1.3.1爆炸复合的基本概念 5
1.3.2爆炸复合研究概况及其动态 5
1.3.3爆炸复合法制备双金属管/棒 6
1.3.4爆炸复合方法与其他方法制备双金属管/棒优缺点比较 8
1.4爆炸复合成波机理的研究 9
1.5爆炸复合数值模拟研究进展 11
1.6本文的主要工作和研究意义 12
第二章 实验材料与实验过程 13
2.1实验材料 13
2.2实验过程 13
2.2.1 Monel/Cu双金属复合棒的制备 13
2.2.2热处理工艺 15
2.2.3界面力学性能测试 15
2.2.4界面微观组织结构和成分分析测试 16
第三章 爆炸复合参数理论及复合窗口的确定 17
3.1参数计算流程 17
3.2爆炸复合参数理论 18
3.2.1碰撞点移动速度Vcp的临界条件 19
3.2.2碰撞点移动速度Vcp 20
3.2.3复层最小飞行速度Vpmin 21
3.2.4复层最大飞行速度Vpmax 21
3.2.5复层的飞行速度Vp 22
3.2.6碰撞角β 22
3.2.7外爆法的装药量与间距 22
3.3爆炸复合窗口的确定 24
3.4蒙乃尔/铜爆炸复合参数 26
3.5本章小结 26
第四章 实验结果及分析 27
4.1宏观形貌 27
4.2金相观察 27
4.3扫描电镜观察 31
4.4复合棒压剪强度实验结果 35
4.5压剪断口形貌及成分分析结果 36
4.6显微硬度测试 37
4.7本章小结 38
第五章 爆炸复合过程的数值模拟 39
5.1 ANSYS/LS-DYNA程序介绍 39
5.1.1概述 39
5.1.2 ANSYS/LS-DYNA程序算法 40
5.1.3沙漏控制和人工体积粘性 42
5.1.4显式动力分析 42
5.2有限元模型的建立 43
5.3材料模型 44
5.4数值模拟结果与讨论 46
5.4.1复层运动速度 47
5.4.2碰撞点区域移动速度 48
5.4.3碰撞点区域的压力场 49
5.4.4剪切应力和等效塑性应变分布 50
5.4.5碰撞点区域的温度场 51
5.5 本章小结 51
第六章 结论与展望 53
6.1 主要结论 53
6.2 展望 53
参考文献 55
致谢 60