• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2016, Vol. 52 ›› Issue (17): 65-71.doi: 10.3901/JME.2016.17.065

• 精密加工制造技术专栏 • 上一篇    下一篇

基于变切深纳米刻划的K9玻璃表面成形特征及去除机制研究*

张飞虎, 李琛, 孟彬彬, 赵航, 刘忠德   

  1. 哈尔滨工业大学机电工程学院 哈尔滨 150001
  • 出版日期:2016-09-05 发布日期:2016-09-05
  • 作者简介:张飞虎,男,1964年出生,博士,教授,博士研究生导师。主要研究方向为精密超精密加工与纳米加工技术。E-mail:zhangfh@hit.edu.cn李琛(通信作者),男,1992年出生,博士研究生。主要研究方向为精密超精密加工与纳米加工技术。E-mail:hit_chenli@163.com
  • 基金资助:
    * 国家自然科学基金(51175126)和国家重点基础研究发展计划(973计划,2011CB013202)资助项目; 20150905收到初稿,20160615收到修改稿;

Investigation of Surface Deformation Characteristic and Removal Mechanism for K9 Glass Based on Varied Cutting-depth Nano-scratch

ZHANG Feihu, LI Chen, MENG Binbin, ZHAO Hang, LIU Zhongde   

  1. School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001
  • Online:2016-09-05 Published:2016-09-05

摘要:

采用Berkovich压头,在纳米压痕仪上对K9光学玻璃进行了变切深纳米刻划试验。为探究摩擦因数与脆塑转变的深度,基于非线性最小二乘法对法向力、切向力关于刻划深度进行了拟合,并利用相关系数r检验其可靠性。利用AFM和SEM对刻划沟槽表面形貌进行分析,刻划过程存在弹塑转变、塑性去除和脆性断裂三个阶段。基于Hertz接触理论求得K9玻璃弹塑转变深度,根据AFM和SEM的结果,以裂纹刚开始萌生作为脆塑转变点,获得脆塑转变的临界深度。基于脆塑转变深度,通过添加修正系数,改进WEI提出的脆塑转变表征方法,建立了用摩擦因数来表征K9玻璃脆塑转变的表达式。通过分析压头在刻划过程中与工件产生的摩擦区,对脆性断裂阶段裂纹的产生和裂纹方向与刻划方向近似呈60°进行了解释。

关键词: K9玻璃, 脆塑转变, 去除特征, 变切深纳米刻划

Abstract:

The experiment of varied cutting-depth nanoscratching for K9 glass is carried out on nano indenter system by Berkovich indenter. To explore the relationship between the friction coefficient and depth of brittle-to-ductile transition, the equation of the normal force and tangential force on the depth are fitted based on nonlinear least square method, which is tested by the correlation coefficientr. The surface morphology of groove is analyzed by AFM and SEM, which find that there are three regimes(elastic-plastic transition regime, plastic removal regime and brittle fracture regime) in scratching process. The depth of elastic-plastic transition for K9 glass is obtained based on Hertz contact theory. According to the results of AFM and SEM, the critical depth of brittle-to-ductile transition is obtained with regarding the first crack as brittle-to-ductile transition point. Based on the depth of brittle-to-ductile transition, the characterization method of brittle-to-ductile transition proposed by WEI is improved by adding the correction factor. The new characterization method of brittle-to-ductile transition for K9 glass is established by the friction coefficient. By analyzing the generation of friction zone causing by the friction of indenter and workpiece in scratching process, the generation of cracks and the angle between the direction of crack and the scratching direction which is about 60° are explained.

Key words: ductile-to-brittle transition, K9 glass, removal characteristic, varied cutting-depth nano-scratch