摘要
使用RDL05电子蠕变疲劳试验机,在试验温度为650℃、孔隙率为31.27%和52.97%、应力为0.05,0.1,0.15 MPa条件下,分别对多孔Cu-35Ni-10Al合金在熔融Li2CO3-38%K2CO3环境下进行压缩蠕变试验,获得了多孔Cu-35Ni-10Al合金时间-应变曲线。采用JSM6360LV扫描电镜对样品蠕变前后的显微形貌进行观察和能谱分析,综合考虑熔盐环境、孔隙率大小及载荷大小对材料蠕变性能的影响。研究结果表明,碳酸熔融盐环境、较高的孔隙率和较大的载荷均能加速多孔铜材料的蠕变。当应力超过0.1 MPa时,蠕变速率会出现明显的增大;当应力较小时,腐蚀与载荷的混合作用主要集中在材料的富铜相中。而随着应力的增大,贫铜相也逐渐受到侵蚀并生成圆环状腐蚀产物,但其原始形貌并未改变。另外,在合金材料中,Al元素含量较低处易受到熔融碳酸盐的侵蚀。分析表明,熔盐环境、外加应力、孔洞尺寸及表面元素分布共同决定了该合金的变形机制。
The compressive creep test is conducted on porous Cu-35Ni-10 Al alloys in molten Li2CO3-38%K2CO3environment,with the utilization of the RDL05 electronic creepfatigue testing machine,at a test temperature of 650 ℃,with different porosities,and under different stress conditions,then the time-strain change curve of porous Cu-35Ni-10 Al alloy is obtained.JSM6360 LV scanning electron microscope and energy spectrum analysis was used to observe the microstructure of the specimen before and after the creep test.The effect of molten salt environment,porosity size and load level on creep properties of materials are comprehensively considered.The result shows that creep can be accelerated by molten salts,high load stress and large porosity.When the load stress is higher than 0.1 MPa,an evident increase of steady creep rate is obtained.At the initial stage,the molten salts corrosion is mainly concen-trated on the copper-rich phase.However,copper-poor phases are gradually corroded with the increase of load stresses.Annular corrosion products are observed surrounding the phases but the original morphology of which does not change.Moreover,areas where the contents of Al are relative low are easily corroded by molten carbonate.The analysis shows that the molten salts condition,load stresses,size of the pores and the elements distribution are the joint factors to decide the deformation mechanism of Cu-35Ni-10 Al alloys.
出处
《长沙理工大学学报（自然科学版）》
CAS
2016年第1期62-68,共7页
Journal of Changsha University of Science and Technology:Natural Science
基金
国家自然科学基金资助项目(51075044)
湖南省高校创新平台开放基金项目(13k052)
