摘要
分别以Ti-B4C-C体系和Ti-B4C-C-Al体系复合粉为反应原料,利用自反应喷射成形技术制备Ti(C,N)-TiB2基复合陶瓷坯件.利用XRD、SEM、EDS、TEM等方法,研究分析了向喷射体系中加入5wt%金属Al对喷射沉积坯件组织结构、主要力学性能的影响及其原因.结果表明,Ti-B4C-C体系的喷射沉积坯件主要由TiC0.3N0.7和TiB2主相及TiO2副产物相组成,其致密度、维氏硬度、弯曲强度、断裂韧性等性能分别为97.2%、17.3GPa、387MPa、6.0MPa.m1/2;喷射体系中添加5wt%金属Al后,喷射沉积坯件的主相仍为TiC0.3N0.7和TiB2,但副产物相中不含有害相TiO2,而增加了对复合材料有益的Al2O3与Ti3Al相,坯件内TiB2颗粒长径比增大,出现大量长棒状晶,并使坯件的致密度、维氏硬度、弯曲强度、断裂韧性等性能也分别提高到97.7%、20.6GPa、425MPa、7.3MPa.m1/2.可见金属Al的添加可有效抑制喷射过程中Ti的氧化,明显改善喷射沉积坯件的综合力学性能.
With composite powders of Ti-B4C-C and Ti-B4C-C-Al systems as reactants,Ti（C,N）-TiB2-based com-posite ceramic preforms were prepared by self-reactive spray forming technology.XRD,SEM,EDS and TEM were used to investigate the influence of 5wt% Al addition on the structure and properties of the preforms.It was shown that the performs made from Ti-B4C-C system were mainly composed of TiC0.3N0.7 and TiB2,with by-product phase of TiO2.Relative density,Vickers hardness,flexural strength and fracture toughness of Ti-B4C-C preforms were 97.2%,17.3GPa,387MPa and 6.0MPa.m1/2,respectively.By adding 5wt%Al in the sprayed system,the by-product of the preforms was the desirable phases of Al2O3 and Ti3Al,not TiO2,though the main phases of Ti-B4C-C-Al preforms remained to be TiC0.3N0.7 and TiB2.The length to diameter ratio of the TiB2 grains increased obviously.As a result,relative density,Vickers hardness,flexural strength and fracture toughness of Ti-B4C-C-Al preforms as-cended to be 97.7%,20.6GPa,425MPa and 7.3MPa.m1/2,respectively.The additive Al effectively restrained the oxidation of Ti in the spray forming process,which improved the mechanical properties of the preforms greatly.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第7期715-720,共6页
Journal of Inorganic Materials
基金
国家自然科学基金(51001118
50672130)~~
