J4 ›› 2009, Vol. 20 ›› Issue (20): 0-2519.

• 材料工程 •    

Zr基大块非晶合金在过冷液相区超塑性成形的摩擦行为及机理研究

郑志镇;成蛟;王新云;李建军   

  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2009-10-25 发布日期:2009-10-25

Study on the Friction Behavior and Mechanism of Zr-based Bulk Metallic Glass Superplastic Forming in the Supercooled Liquid Region

Zheng Zhizhen;Cheng Jiao;Wang Xinyun;Li Jianjun   

  • Received:1900-01-01 Revised:1900-01-01 Online:2009-10-25 Published:2009-10-25

摘要:

采用双杯挤压方法研究了成形温度、应变速率等工艺参数对Zr55Al10Ni5Cu30块体非晶合金在过冷液相区塑性成形时模具和零件之间的摩擦行为的影响。采用有限元模拟方法获得大块非晶合金双杯挤压的摩擦因数标定曲线,有限元模拟中非晶合金的变形采用Kawamura的本构模型,将高温压缩实验的数据拟合,获得本构模型中的参数,结果表明非晶合金在过冷液相区内变形的摩擦因数在0.2~0.7之间。当应变速率较低时,随着温度的升高,摩擦因数总体上降低;而当应变速率较高时,随着温度的升高,摩擦因数先略有上升,然后急剧下降。当温度较低时,随着应变速率增大,摩擦因数显著增大,而在高温时,随着应变速率增大,摩擦因数略微有所减小。按照现代摩擦理论对非晶合金在过冷液相区内成形的摩擦机理进行了分析,认为黏着是摩擦的主导因素。

关键词: Zr基非晶合金, 过冷液相区, 双杯挤压;摩擦行为;摩擦机理

Abstract:

The friction behavior of Zr55Al10Ni5Cu30 bulk metallic glass in the supercooled liquid region was investigated. The influence of forming temperature and velocity on friction factor was established by double cup extrusion test. The calibration curves of friction factor were evaluated by FE simulation
and Kawamura’s constitutive equation was adopted. Constant parameters in the constitutive equation were acquired by fitting the data from compression test. The results indicate that the friction factor of bulk metallic glass forming in the supercooled liquid region is between 0.2 and 0.7. With the temperature rising, the friction factor decreases in general under a low forming velocity. However, the friction factor increases slightly and then decreases abruptly under a high forming velocity. In low temperature area of supercooled liquid region, the friction factor increases abruptly with increasing of the forming velocity. While in high temperature area of supercooled liquid region, the friction factor decreases
slightly with increasing of the forming velocity. The friction mechanism of bulk metallic glass forming in supercooled liquid region was analyzed by modern tribology theory. Adhesion is the dominant factor contributing to the friction of bulk metallic glass.

Key words: Zr-based bulk metallic glass;supercooled liquid region;double cup extrusion test, friction behavior, friction mechanism

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