【作者】 闫鸿浩；

【导师】 李洪升； 李晓杰；

【作者基本信息】 大连理工大学 ， 工程力学， 2003， 博士

【摘要】 非晶态合金是新型功能材料研究的热点之一。采用从熔体直接快淬方法可以生产出一系列非晶态金属材料，由于在合金微观结构上呈现高度无序的玻璃态，使得合金有许多不同于普通金属的性能。许多非晶态合金材料兼有众多优异性能于一身，如同时具备高强度、高硬度、优异的磁学性能，抗腐蚀性等等。这样开发非晶态合金材料具有广泛的应用范围和极大的开发价值。但是，由于快淬形成的特点所决定，一般非晶态合金只能以条带、薄片与粉末形式存在。为此，开发块体非晶态合金成为这类功能材料实用化的焦点问题。总结非晶态块体合金制备技术可以归纳为四个方向，即粉末冶金技术、固态反应、从液相中直接制取、爆炸加工等等。本论文重点研究非晶态合金块体的爆炸焊接制备技术。论文主要研究成果有： 1．针对多层非晶态合金薄带爆炸焊接的特殊性，提出了“薄带爆炸焊接理论窗口”，对焊接上、下限、流动限分别给予新的限定。 2．多层非晶态合金薄带爆炸焊接后的样品中有时出现宏观和微观裂纹。为了减少裂纹的产生需对爆炸焊接界面附近的应变率、应变分布规律进行分析。论文中采用理想流体对称碰撞模型沿流线详细研究驻点近区的沿流线应变率、应变分布规律。并且发现了焊接界面附近最大应变率出现的位置及其分布规律，为分析界面绝热剪切带形成打下了基础。在焊接界面附近应变计算中得到了在相同碰撞速度、不同爆速下的整体应变分布规律。 3．爆炸焊接界面附近温升是由爆炸绝热压缩和畸变形能沉积两者造成的。通过计算绝热压缩温升和畸变形能沉积产生的温升，给出熔化判据，定量估计出了在小碰撞角下爆炸焊接界面熔化层厚度。 4．结合爆炸焊接传热的特殊性和焊接界面熔化层厚度计算，提出用一种方波型温度场模型来解释非晶态薄带爆炸焊接后能保证非晶态的原因。结果表明该模型很好解释这一现象：多层非晶态薄带爆炸焊接后，界面能保持很好的非晶态。 5．实验上，论文中完成了20～120层，25μm厚非晶薄带的爆炸焊接，焊件分别制成板状件与管状件。同时也完成了单层非晶态薄带与普通钢的焊接实验。更多还原

【Abstract】 Amorphous alloys have various useful properties such as high strength, soft magnetism and high corrosion resistance. The shapes of these alloys, however, are limited mainly to ribbons, wires, powders, or thin film, because of high quenching rate generally required to preserve the amorphous state from liquid state, This imposed serious limitation on the amorphous state from liquid state and then on the application fields of amorphous alloys. In order to make full use of the potentially useful properties of amorphous alloys and extend the potentially useful properties of amorphous alloys as well as the industrial application, it is very necessary to prepare amorphous alloys in a bulky form. Many research works have been carried out to prepare amorphous alloy compacts. The current researches can be sorted as four aspects, namely, powder metallurgy technique, solid state reaction, making bulk amorphous alloys from melt directly and explosive machining. Bulk amorphous alloys manufactured with explosive welding of explosive machining is researched detailed. It can dispose of the oxide films and the amorphous state of the amorphous ribbons welded can be maintained in bulk samples. Research products worked out are as follows:1. "Foils academic explosive welding window" is put forward based on the particularity of explosive welding for multi-layer amorphous ribbons. Welding upper limit, down limit and flow limit are qualified newly.2. Macroscopical and microcosmic cracks appear in bulk amorphous alloys produced by explosive welding some times. To prevent it, strain rate and strain near explosive welding interface must be researched. In this paper, an ideal fluid model of symmetrically colliding is taken to analyze the distribution rule of strain rate and strain on streamline. Points position for maximum equivalent strain rate are found out, It is useful for analyzing adiabatic shear bands(ASB). Whole strain distribution rules with same colliding speed, different explosive speed are calculated.3. Temperature rising near explosive welding interface is caused by explosive adiabatic compression of temperature and sedimentary abnormality deformation energy. Throughcalculation of temperature rising callused by them, melt criterion is given, the thickness of melted layer near explosive welding interface with small collision angle is estimated.4. Based on analysis of characters of amorphous alloys producing and heat exchange during explosive welding ,a square wave model for the temperature field across the interface during explosive welding for multi-layer foils has been proposed. The model can be used to analyze the reason of amorphous state kept across the interface after explosive welding, and results accord with the matters of fact very well.5. Explosive welding of amorphous alloys with 20~120 layers. 25um thickness hasbeen carried out. Amorphous alloys board and tube are explosive welded well. At the same time, single layer amorphous alloys can been welded on general steel well.更多还原