中国物理B ›› 2018, Vol. 27 ›› Issue (10): 106201-106201.doi: 10.1088/1674-1056/27/10/106201

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Unusual softening behavior of yield strength in niobium at high pressures

Qiu-Min Jing(敬秋民), Qiang He(何强), Yi Zhang(张毅), Shou-Rui Li(李守瑞), Lei Liu(柳雷), Qi-Yue Hou(侯琪玥), Hua-Yun Geng(耿华运), Yan Bi(毕延), Yu-Ying Yu(俞宇颖), Qiang Wu(吴强)   

  1. National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China
  • 收稿日期:2018-05-19 修回日期:2018-07-09 出版日期:2018-10-05 发布日期:2018-10-05
  • 通讯作者: Qiu-Min Jing E-mail:j_qm@163.com
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. U1530134, U1730248, 11772312, and 11504354).

Unusual softening behavior of yield strength in niobium at high pressures

Qiu-Min Jing(敬秋民), Qiang He(何强), Yi Zhang(张毅), Shou-Rui Li(李守瑞), Lei Liu(柳雷), Qi-Yue Hou(侯琪玥), Hua-Yun Geng(耿华运), Yan Bi(毕延), Yu-Ying Yu(俞宇颖), Qiang Wu(吴强)   

  1. National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China
  • Received:2018-05-19 Revised:2018-07-09 Online:2018-10-05 Published:2018-10-05
  • Contact: Qiu-Min Jing E-mail:j_qm@163.com
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. U1530134, U1730248, 11772312, and 11504354).

摘要:

In situ synchrotron angle-dispersive x-ray diffraction experiments on niobium powders have been conducted at pressures up to 61 GPa and room temperature using the diamond anvil cell technique. From the full width at half maximum of the measured diffraction lines, the yield strength was derived with the line-width analysis theory. The niobium powder sample was found to be compressed more packed firstly and then yielded at ~14 GPa-18 GPa. Following an initial increase in the yield strength with pressure, an obvious decrease was observed occurring at ~42 GPa-47 GPa accompanying with a typical pressure dependence above 47 GPa. The experimentally observed anomalous softening of the yield strength in niobium surprisingly follows the trend of the predicted unusual softening in the shear modulus by the recent theoretical investigations. The possible mechanisms, applicable to interpret the yield strength softening of materials at high pressure, were also discussed in detail.

关键词: x-ray diffraction, niobium, diamond anvil cell, yield strength, anomalous softening

Abstract:

In situ synchrotron angle-dispersive x-ray diffraction experiments on niobium powders have been conducted at pressures up to 61 GPa and room temperature using the diamond anvil cell technique. From the full width at half maximum of the measured diffraction lines, the yield strength was derived with the line-width analysis theory. The niobium powder sample was found to be compressed more packed firstly and then yielded at ~14 GPa-18 GPa. Following an initial increase in the yield strength with pressure, an obvious decrease was observed occurring at ~42 GPa-47 GPa accompanying with a typical pressure dependence above 47 GPa. The experimentally observed anomalous softening of the yield strength in niobium surprisingly follows the trend of the predicted unusual softening in the shear modulus by the recent theoretical investigations. The possible mechanisms, applicable to interpret the yield strength softening of materials at high pressure, were also discussed in detail.

Key words: x-ray diffraction, niobium, diamond anvil cell, yield strength, anomalous softening

中图分类号:  (High-pressure effects in solids and liquids)

  • 62.50.-p
07.35.+k (High-pressure apparatus; shock tubes; diamond anvil cells) 62.20.F- (Deformation and plasticity) 64.30.Ef (Equations of state of pure metals and alloys)