氮分压对反应溅射(Ti,Al)N薄膜微结构与力学性能的影响

采用Ti-Al复合靶在不同氮分压下制备了一系列(Ti,Al)N薄膜,用EDS、XRD、TEM和微力学探针表征了薄膜的沉积速率、化学成分、微结构和力学性能.结果表明,氮分压对(Ti,Al)N薄膜影响显著:合适的氮分压可以得到化学计量比的(Ti,Al)N薄膜,薄膜为单相组织,并呈现(111)择优取向,最高硬度和弹性模量分别达到34.4GPa和392GPa;过低的氮分压不但会造成薄膜贫氮,而且薄膜中的Al含量偏低,硬度不高;过高的氮分压下,由于存在"靶中毒"现象,尽管薄膜的成分无明显变化,但会大大降低其沉积速率,并使薄膜形成纳米晶或非晶态结构,薄膜的硬度也较低.

Influence of N2 Partial Pressure on Microstructure and Mechanical Properties of Reactively Sputtered (Ti,Al)N Films

Different types of (Ti,Al)N films were grown in a gaseous mixture of argon and nitrogen by reactive sputtering of a Ti-Al composite target under different film growth conditions.The properties of the films were characterized with electron diffraction spectroscopy(EDS),X-ray diffraction(XRD) and transmission electron microscopy(TEM).The results show that N 2 partial pressure significantly affects the microstructures and mechanical properties of the film.At an optimal N 2 partial pressure,single phased film with strong(111) texture and good stoichiometry can be easily grown and that the film displays some favorable mechanical properties,such as a maximum hardness of 34.4 GPa and an elastic module of 392 GPa.However,higher or lower N 2 partial pressures may inversely affect the film quality.For instance,lower N 2 pressure results in Al-poor films with deficiency of N and low hardness.Whereas,higher N 2 pressure leads to target poisoning,reduction of deposition rate,and the growth of amorphous films with much lower hardness.