薄板微成形摩擦尺寸效应及其模具表面固体润滑薄膜改性研究

The development of micro sheet forming was seriously limited because of size effects. Size effects on friction and surface modification with solid lubrication film on mould in micro sheet forming are studied in this project by experimental and theoretical methods from both macro and micro perspectives. A friction test equipment which can realize sliding, stretch bending, stretch bulging and other deformation is developed and the influence law of specimen size on friction coefficient under different lubrication conditions is studied. The state of the contact surface of the sample is analyzed before and after deformation to reveal the mechanism of size effects on friction in micro sheet forming. A friction model considering the size effects is also built. Different solid lubrication films are prepared on the surface of the mold and their performance is analyzed to determine the best suitable deposition process parameters for micro sheet forming. Micro deep drawing based on mould surface modification with solid lubrication film is studied for forming micro cylindrical and rectangular cups with high qualities. Besides this, the mechanism of solid lubrication film in micro sheet forming is also investigated. The implementation of this project will promote the development of micro sheet forming theory and industrial application, and provide significant academic value as well as important economic significance.

由于尺寸效应的影响，严重制约了薄板微成形技术的发展。本项目采用实验研究和理论分析相结合的研究方法，运用宏观和微观分析手段，开展薄板微成形摩擦尺寸效应及其模具表面固体润滑薄膜改性研究。研制可实现滑动、拉弯、拉胀等多种变形方式的薄板微成形摩擦测试设备，研究不同润滑条件下试样尺寸对摩擦系数的影响规律；分析变形前后试样的接触表面状态，揭示薄板微成形摩擦尺寸效应机理，建立考虑尺寸效应的摩擦模型；在薄板微成形模具表面制备不同的固体润滑薄膜并进行性能分析，确定最佳的制备工艺参数；研究基于模具表面固体润滑薄膜改性的微拉深工艺，成形出高质量的微杯形件和微盒形件，阐明薄板微成形条件下固体润滑薄膜的润滑机理。本项目的实施有利于促进薄板微成形理论的发展及薄板微成形工艺的工业化应用，不仅具有重要的学术价值，而且具有十分重要的经济意义。

本项目利用理论分析和实验研究相结合的方法，对薄板微成形过程的摩擦与润滑的若干基础问题进行研究。利用非接触式应变测量装置，研究了薄板微成形流动应力尺寸效应机理及其对摩擦系数的影响规律。研制了薄板微成形滑动摩擦测试装置，研究了润滑条件、成形速度等参数对摩擦系数的影响规律。分析了试样变形前后的表面状态，揭示了摩擦尺寸效应机理，建立了基于库伦定律的薄板微成形摩擦模型。利用等离子体浸没离子注入与沉积技术和磁控溅射技术，在薄板微成形模具表面制备固体润滑薄膜，确定了适合于薄板微成形的薄膜。研制了薄板微拉深成形实验装置，研究了不同工艺参数对微拉深成形的影响，成形出质量良好的微杯形件、微盒形件、微锥杯形件、微半球形件。利用DLC薄膜对微拉深模具表面进行改性，显著提高了微拉深件的表面质量和极限拉深比。本项目的研究成果对于促进薄板微成形工艺的工业化应用，具有十分重要的学术价值和经济意义。