摘要
研究了Ti,Al和TiO_2混合粉体经无特殊气氛保护的高能球磨和真空热压烧结工艺原位合成了TiN/Al_2O_3复合材料,该材料的抗弯强度达到850 MPa,断裂韧性为5.5 MPa·m^(1/2)。利用DTA,XRD及SEM等手段的分析测试结果,结合热力学计算,研究了该粉体的高能球磨过程和球磨粉体在后续热处理中的物相形成及转化规律。结果表明:在球磨过程中粉料吸附并溶解了空气中的N_2和O_2气,在后续热压烧结处理中首先原位反应形成了Ti_2AlN,Al_2O_3以及TiAl,Ti_3Al,TiAl_3等金属间化合物相。随温度的升高Ti_2AlN逐渐分解形成TiN相,当热压温度升高到1300℃时,其它物相基本消失,从而形成了TiN/Al_2O_3复合材料。
The TiN/Al2O3 composites were fabricated via in-situ reaction by high energy milled and hot pressing of Ti-Al-TiO2 composite powder at 1300 ℃. The phase transformation and sintering process were studied by DTA, XRD, SEM and thermodynamics calculation. The mechanical properties and microstructure of TiN/Al2O3 composites were also investigated. The N2 dissolved in powders in the process of the high energy milling, and the phase of Ti2AlN was formed after heat treatment of the milled powders. The Ti2AlN decomposed to the TiN phase at sufficiently high temperatures. The TiN promoted densification of the ceramics and increased their mechanical properties. The TiN-Al2O3 composites hot pressed at 1300 ℃ for 30 min under a pressure of 30MPa have the bending strength of 850 MPa, and the fracture toughness of 5.5 MPa·m^1/2.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2008年第A01期789-792,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金资助项目(50432010
50672056)
陕西科技大学科学研究基金(SUST-B14)
关键词
高能球磨
原位反应
TiN/Al2O3
力学性能
high energy milling
in situ reaction
TiN/Al2O3
composite ceramic
mechanical properties
