强流脉冲离子束辐照TA1与TC4表面形貌特征

Surface Morphology of TA1 and TC4 Irradiated by High-intensity Pulsed Ion Beam

强流脉冲离子束（HIPIB）以其高密度能量沉积的特点,被广泛应用在材料表面改性上.本实验采用用强流脉冲离子束脉冲辐照工业纯钛TA1与钛合金TC4,实验参数为：束流结构为70％C＋ ＋30％H＋,加速电压为250kV,束流密度为170～200A/cm2,束流脉冲宽度为80ns.分别研究5次、10次、15次和20次辐照下表面形貌特征.结果表明：辐照后材料表面在热力学作用下先后形成带状发亮“山脊”及环状起伏形貌;在表层选择性烧蚀作用下形成内部光滑的凹坑,在亚表层喷发作用下有中间带空洞的凹坑产生;随着辐照次数的增加,材料表层及亚表层的成分及结构趋于均匀,热传导及力学作用亦趋于稳定平衡,TA1表面起伏和凹坑逐渐减少甚至消失,逐渐趋于光滑;由于相界的存在,TC4表面还有少数相界处选择性烧蚀及喷发所形成凹坑.

High-Intensity Pulsed Ion Beam （HIPIB） has been widespreadly used in the modification of material surface due to its high power density and high energy deposition density. TA1 commercially pure titanium and TC4 titanium alloy were irradiated by HIPIB （ constituted by 70% carbon ions and 30% proton） with 250 kV acceleration voltage, 170 - 200 A/cm2 current density and 80 ns pulse duration in this work to investigate the material＇ s morphology. The number of irradiation is 5,10,15 and 20 respectively. It is noted that zonal light＂ ridge＂ and annular fluctuation morphology are formed on surface of TA1 and TC4 under the thermodynamic function of irradiation;Smooth craters are formed under se- lectivity ablation and craters that contain caves are formed too under near-surface layers e- ruption. The composition and structure of surface and near-surface layers tend to be more u- niform and heat conduction and the mechanical effect tend to be at equilibrium with the irra- diation number increase. The number of fluctuation and crater on the surface of TA1 decrea- ses, and the surface tend to be smooth;On the of TC4, there are a few craters formed fromnear-surface layers selectivity ablation and eruption due to the existence of phase bounda- ries.