非晶合金在振动载荷作用下的热塑性微成形机理研究

Amorphous alloys have advanced into a class of fascinating micro-forming materials due to the absence of crystalline structures, excellent mechanical properties, and unique superplastic behavior in the supercooled liquid region. However, the high viscosity and interfacial friction during microforming impose grand challenges in applications of this kind of material in the field of micro/nano manufacturing. Vibration assisted plastic forming technique has been proposed to mitigate this issue, but the fundamental understanding of this process has been very limited. In the present project, the micro-scale sample will be selected , and a systematic study will be carried out to understand the following open puzzles: (1) Effect of vibrational loading on the viscosity of supercooled liquid amorphous alloys and the underlying mechanism; (2) The role of vibrational loading in interfacial interaction between the amorphous alloy and the micro-mould cavity surface and the related mechanism; (3) Effect of vibrational loading on the rheological behavior of amorphous alloy along the micro-mould cavity; (4) Effect of vibrational loading on the microstructure and mechanical properties of the micro-parts. The above mentioned research can shed light on understanding the effect and mechanistic origin of vibrational loading on the viscosity of amorphous alloy, interfacial interaction, material flow, microstructure and mechanical properties of the micro-parts. This project is also important for establishing favorable thermoplastic microforming protocols and revealing the related mechanism for amorphous alloys under vibrational loading. From a practical viewpoint, this project is of great significance for the manufacture of amorphous alloy micro-devices with high precision as well as excellent properties, and for its practical application in the field of micro-machining.

非晶合金由于没有晶粒、机械性能优异、在过冷液态区可超塑性成形等特点而成为一类重要的微成形材料。但过冷液态非晶合金的高粘度和微成形时的界面摩擦严重制约了这类材料在微纳制造领域的应用。振动塑性成形技术有望解决上述难题。但目前针对该方面的研究仍十分欠缺，其中涉及的一些重要科学问题尚缺乏深入理解。本项目拟以微尺度样品为研究对象，深入开展以下研究：（1）振动加载对过冷液态非晶合金粘度的影响及机理；（2）振动加载对非晶合金与微尺度模具表面间界面摩擦的影响及机理；（3）振动加载对微尺度模具中非晶合金流动行为的影响；（4）振动加载对微成形件微观组织结构和力学性能的影响。通过以上研究，阐明振动加载对非晶合金粘度、界面摩擦、材料流动、成形件微观组织结构及力学性能的影响规律，揭示非晶合金的振动加载热塑性微成形机理。本项目研究将对制造高精度、性能优异的非晶合金微器件，促进其在微细加工领域的实际应用具有重要意义。

非晶合金由于没有晶粒、机械性能优异、在过冷液态区可超塑性成形等特点而成为一类重要的微成形材料。但过冷液态非晶合金的高粘度和微成形时的界面摩擦严重制约了这类材料在微纳制造领域的应用。振动塑性成形技术有望解决上述难题。但目前针对该方面的研究仍十分欠缺，其中涉及的一些重要科学问题尚缺乏深入理解。本项目主要以微尺度样品为研究对象，深入开展如下重要研究：（1）振动加载对过冷液态非晶合金粘度的影响及机理；（2）振动加载对非晶合金与微尺度模具表面间界面摩擦的影响及机理；（3）振动加载对微尺度模具中非晶合金流动行为的影响；（4）振动加载对微成形件微观组织结构和力学性能的影响。此外，根据国际研究前沿发展动态，重点研究了“（5）振动加载对过冷液态非晶合金热塑性成形能力的影响机理研究”，以及“（6）非晶基复合材料的振动加载热塑性成形制备研究”。.取得的重要进展如：（1）超声振动热塑性成形制备出高强度（1GPa）高断裂韧性（230 MPa•m1/2）的非晶基复合材料；（2）揭示了振动加载条件下非晶合金的热塑性成形机理；（3）研发出热压成形非晶合金表面几何微结构调控摩擦系数新技术；（4）建立起了高熵非晶合金的形变图；（5）揭示了振动加载激活非晶合金流动单元的影响机理。.通过以上研究，阐明振动加载对非晶合金粘度、界面摩擦、材料流动、成形件微观组织结构及力学性能的影响规律，揭示非晶合金的振动加载热塑性微成形机理。本项目研究将对制造高精度、性能优异的非晶合金微器件，促进其在微细加工领域的实际应用具有重要意义。