硼含量对单晶Ni_3Al力学性能的影响

THE INFLUENCE OF BORON CONTENT ON MECHANICAL PROPERTIES OF Ni_3 Al SINGLE CRYSTAL

本文研究了硼含量为0、0.52、1.37、2.22和3.00at％的Ni_3Al单晶的组织以及在室温和高温的力学性能。结果表明,随着硼含量增加,室温和800℃的抗张强度和屈服强度不断提高,分别在1.37和0.52at％B时达到最高值,进一步提高硼含量,由于组织中析出硼化物共晶而使性能恶化。850℃,100MPa条件下的持久时间和持久延伸率均随硼含量的提高而不断地明显降低,但与同样成分的多晶Ni_3Al比较,它们都提高1个或2个数量级。

The relationship between Ni_3Al single crystal structures with Boron contents of 0, 0.52, 1.37, 2.22 and 3.00 at % and their mechanical properties at room and high temperatre is studied in this paper. It shows that as the Boron content grows, the tensile strength and yield strength of Ni_3Al single crystal at room temperature and 800℃ increase continuously. The maximums are obtained at contents of 1.37 and 0.52at % B respectively. If the Boron content continue to grow, boride eutectic will separate out from Ni_3Al structure and make its property worse.At 850℃, 100MPa, rupture time and elongation of Ni_3Al will obviously decrease with the increase of Boron content. But compared with Ni_3Al polycrystal of the same composition, the rupture time and elongation will be one to two order of magnitude higher.