Page 99 - 《爆炸与冲击》2025年第12期

第 45 卷 第 12 期 爆 炸 与 冲 击 Vol. 45, No. 12
2025 年 12 月 EXPLOSION AND SHOCK WAVES Dec., 2025

DOI：10.11883/bzycj-2025-0050

铱合金在高温下的动态拉伸力学性能 *

陈军红，张方举，胡文军

（中国工程物理研究院总体工程研究所，四川 绵阳 621999）

摘要： 基于大电流加热方式建立了小尺寸板状试样高温动态拉伸实验技术，解决了片状试样与波导杆之间有效
连接、试样高温实现与温度保持、高温试样与波导杆冷接触时间精准控制三项关键技术。为获取铱合金高温动态拉
伸力学性能，利用该实验技术对铱合金进行了 10 s 应变率下室温、600、900 和 1 100 ℃ 下的拉伸实验。结果表明，当
3
−1
温度从室温上升到 900 ℃ 时，铱合金拉伸强度下降了 12%，延性增加了 2 倍，但当温度上升至 1 100 ℃ 时，铱合金拉伸
强度下降了 43% 且延性增加了 7.3 倍。基于铱合金试样宏微观断裂形貌表征阐明了其变形机理。随着温度的升高，铱
合金由沿晶断裂主控的断裂模式转变为晶粒高温软化断裂主控的断裂模式，晶界失效和晶粒高温软化屈服两者相互
竞争，决定了铱合金的高温动态断裂行为。
关键词： 分离式霍普金森拉杆；铱合金；高温；动态拉伸；失效机理
中图分类号： O347.3; TN47 国标学科代码： 13015 文献标志码： A

Dynamic high-temperature tensile characterization of an iridium alloy

CHEN Junhong, ZHANG Fangju, HU Wenjun
（Institute of System Engineering, China Academy of Engineering Physics, Mianyang 621999, Sichuan, China）

Abstract: Iridium alloys have been extensively utilized as structural materials in specific high-temperature applications,
attributed to their superior strength and ductility at elevated temperatures. To enhance the understanding of high-speed impacts
at elevated temperatures, it is imperative to characterize the mechanical properties of iridium alloys, including their failure
response under high strain rates and elevated temperatures. In this study, the conventional split Hopkinson tension bar
technique was modified to evaluate the tensile behavior of an iridium alloy at high strain rates and elevated temperatures. A
dynamic high-temperature tensile testing technique for thin and flat specimens was established based on the high current
heating method. A fixture with a slot was employed, enabling the specimen shoulder to bear the load and transmit it to the
gauge section of the specimen. An integrated high current heater equipped with a self-controlled system was utilized to heat the
iridium alloy specimen and maintain the desired high-temperature conditions. To prevent unintended heating of the bars, a pair
of hollow water-cooled pillow blocks were installed. Moreover, to mitigate rapid cooling of the specimen, the cold contact time
was meticulously controlled to be less than 1 ms. To elucidate the dynamic high-temperature properties of the iridium alloy,
3
−1
tensile tests were conducted using this technique at a strain rate of 10 s and at temperatures of room temperature, 600, 900,
and 1 100 ℃. Experimental results revealed that as the temperature increased from room temperature to 900 ℃, the tensile
strength of the iridium alloy decreased by 12%, while its ductility doubled. However, when the temperature was further
elevated to 1 100 ℃, the tensile strength decreased by 43%, and the ductility increased by a factor of 7.3. Macroscopic and
microscopic analyses of the fracture morphologies were conducted to reveal the deformation mechanisms of the iridium alloy.
It was found that with increasing temperature, the failure mode of the iridium alloy transitioned from predominantly

* 收稿日期： 2025-02-16；修回日期： 2025-06-07
基金项目： 国家自然科学基金 (12172344)
第一作者： 陈军红（1987－ ），男，博士，副研究员，chenjh@lnm.imech.ac.cn
通信作者： 张方举（1970－ ），男，本科，研究员，zhangfj@caep.cn

123103-1