通过铬强化铁镍因瓦合金。

Strengthening of the Fe-Ni Invar Alloy Through Chromium.

作者信息

Sui Qingshuang, He Jun, Zhang Xin, Sun Zhonghua, Zhang Yunfei, Wu Yingfei, Zhu Zhixiang, Zhang Qiang, Peng Huifen

机构信息

School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, China.

HBIS Group Technology Research Institute, HBIS Group, Shijiazhuang 052165, China.

出版信息

Materials (Basel). 2019 Apr 20;12(8):1297. doi: 10.3390/ma12081297.

DOI:10.3390/ma12081297

PMID:31010010

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6515356/

Abstract

Invar alloys with both high strength and low thermal expansion are urgently needed in fields such as overhead power transmission, aero-molds, and so on. In this paper, Cr was introduced as a cost-efficient alloying element into the Fe-36Ni binary invar alloy to increase its mechanical strength. Our results confirmed that fine CrC precipitants, together with some FeC, in the invar alloy aged at 425 °C could be obtained with a short aging time. Those precipitants then grew and aggregated at grain or sub-grain boundaries with an increase in aging time. Simultaneously, mechanical strength and coefficient of thermal expansion (CTE) parabolically varied with the increase in aging time. The sample aged at 425 °C for 7 h presented a maximum strength of 644.4 MPa, together with a minimum coefficient of thermal expansion of 3.30 × 10 K in the temperature range of 20-100 °C. This optimized result should be primarily attributed to the precipitation of the nanoscaled CrC.

摘要

在架空输电、航空模具等领域，迫切需要兼具高强度和低热膨胀率的因瓦合金。本文将Cr作为一种经济高效的合金元素引入Fe-36Ni二元因瓦合金中，以提高其机械强度。我们的结果证实，在425℃时效的因瓦合金中，短时效时间即可获得细小的CrC沉淀相，以及一些FeC。随着时效时间的增加，这些沉淀相在晶粒或亚晶界处长大并聚集。同时，机械强度和热膨胀系数（CTE）随时效时间的增加呈抛物线变化。在425℃时效7 h的样品，在20-100℃温度范围内呈现出644.4 MPa的最大强度，以及3.30×10 K的最小热膨胀系数。这一优化结果主要归因于纳米级CrC的析出。