变形工艺对低密度铌合金组织及性能的影响

Effect of deformation process on Microstructure and properties of low density niobium alloy

摘要:

低密度铌合金具有密度低、熔点高、耐腐蚀性好等特点,广泛应用于航空航天、核工程、高温结构等领域。为研究不同变形工艺对低密度铌合金组织及性能的影响,本文分别对低密度铌合金进行了轧制和挤压变形,通过OM、SEM观察,力学性能测试等方法进行了探究。结果表明：采用轧制变形时,变形量大,微观组织较均匀,第二相弥散分布,强度较高的同时塑性较好,断后伸长率可达37%；采用挤压变形时,易应力集中而开裂,变形不易深入,微观组织不易均匀,强度较高,但塑性仅有15%,对变形组织对性能的影响进行了分析,可指导铌合金的加工。

关键词:低密度铌合金;轧制变形;挤压变形;显微组织;力学性能

Abstract:

Low-density niobium alloys have characteristics such as low density, high melting point, and good corrosion resistance, and are widely used in aerospace, nuclear engineering, high-temperature structures, and other fields. To study the effect of different deformation processes on the microstructure and properties of low-density niobium alloys, rolling and extrusion deformations were carried out on the low-density niobium alloys in this study, and the effects were investigated through OM, SEM observation, mechanical property testing, and other methods. The results indicate that when rolling deformation is used, the deformation is large, the microstructure is uniform, the second phase is dispersed, the strength is high, and the plasticity is good, with an elongation after fracture of up to 37 %. When extrusion deformation is used, stress concentration can easily lead to cracking, and deformation is not easy to penetrate. The microstructure is not uniform, and the strength is high, but the plasticity is only 15 %, the impact of deformed microstructure on mechanical properties has been analyzed, which can guide the processing of niobium alloys.

Key words:low density Niobium alloy; rolling deformation; extrusion deformation; microstructure; mechanical properties