纯钛表面电解液微弧碳氮化制备碳氮化钛厚膜

PREPARATION OF Ti(C_xN_(1-x))THICK FILMS ON TITANIUM BY PLASMA ELECTROLYTIC CARBONITRIDING

采用电解液微弧碳氮化技术(PECN),在纯钛试样表面沉积出较厚且与基体结合牢固的多孔纳米Ti(C_xN_(1-x))改性层,研究了改性层结构和组成随PECN处理时间的演变规律.结果表明:随放电处理时间延长,PECN-Ti(C_xN_(1-x))膜层厚度、膜层中C/N的原子比以及微孔直径皆增加.处理150 min时,Ti(C_xN_(1-x))膜层厚度可达15μm,且膜层是由晶粒尺寸为40—60 nm的纳米晶粒组成.处理过程中有氢渗入,并在Ti(C_xN_(1-x))层下面形成富含TiH_2的过渡层.后期的真空退火处理可以将氢除去使TiH_2完全分解,而不影响表面Ti(C_xN_(1-x))膜的成分和形貌.

Porous nanocrystalline Ti（CxN1-x） thick films firmly bond to the substrate were obtained on commercial pure titanium by plasma electrolytic carbonitriding （PECN）. The evolutions of the microstructure and phase composition of the PECN modified film with the treatment time were investigated. The results show that the thickness, ratio of C/N and pores size of the film tend to increase with the discharge time. When discharge treated for 150 min, the film is about 15 μm in thickness and exhibits nanocrystalline characteristic with a grain size range of 40-60 nm. The TiH2- riched layer induced by the permeation of hydrogen during the PECN locates beneath the film, and it can be completely removed by subsequent vacuum annealing treatment while the composition and surface morphology of the Ti（CxN1-x） film keep unchanged.