Fabrication, mechanical properties and high temperature oxidation behaviors of ZrN and CrN based hard coatings

现代加工业的发展，特别是高速切削、干切削工艺的出现以及日益增多的难加工材料，对刀具涂层提出了越来越严格的要求，苛刻的服役条件要求刀具涂层必须具备更高的硬度、耐磨性、高温抗氧化性以及足够的强度和韧性。广泛应用的TiN、TiC涂层以及在此基础上发展起来的TiCN，TiAlN、TiAlCN等单层/多层硬质涂层，已不能够满足现代加工业的发展对刀具涂层材料提出的更高要求。由于非钛的ZrN、CrN基硬质涂层具有优异的力学、高温抗氧化性能以及在加工钛及钛合金、高速干式切削工艺中的优越性，成为目前硬质涂层领域的研究热点。近十年来，研究者们对ZrN、CrN基硬质涂层已经开展了相关研究，并且能够制备出一些具有良好...With the development of the modern factory, especially the appearance of high speed dry machining and an increasing number of difficult to machining materials, the requests on hard coatings deposited on cutting tools are more and more restrict. Due to the severe service conditions, the hard coatings must possess higher hardness, better wear and high temperature oxidation resistance, sufficient str...学位：理学博士院系专业：化学化工学院化学系_应用化学学号：2052009015334

沉积温度对纳米ZrN涂层结构及性能的影响

利用磁控溅射方法通过改变沉积温度(Ts)制备一系列纳米ZrN涂层.采用X射线衍射、扫描电镜及CSM纳米力学综合测试系统表征了纳米ZrN涂层的物相结构、截面形貌及综合力学性能,系统研究了沉积温度对纳米ZrN涂层结构及性能的影响.实验结果表明:随着沉积温度的增加,涂层择优取向由(111)变为(200),而在600℃时结晶度很低;涂层择优取向的变化是由涂层沉积过程中原子迁移能力和不同取向表面能的差异所决定的.纳米ZrN涂层在Ts=450℃及以下温度区间为柱状结构,并随沉积温度增加柱状晶逐渐变宽,在Ts=600℃时,由于生长方式的改变使涂层变为非柱状等轴结构.纳米ZrN涂层的硬度在Ts=450℃及以下温度区间没有明显变化,但在Ts=600℃时,由于涂层结晶度以及位错密度降低导致涂层硬度下降.随沉积温度的增加,涂层与基体间结合力先减小后增大.纳米ZrN涂层的磨损率由硬度和膜基结合力共同作用决定

Zr_(1-x)Si_xN纳米涂层的制备及其力学性能

采用直流与射频共溅射技术制备Zr1-xSixN纳米涂层。通过改变Si靶溅射功率控制涂层中Si含量,研究了不同Si含量对Zr1-xSixN涂层的物相结构、晶粒尺寸、硬度和摩擦磨损性能的影响,探索了Zr1-xSixN纳米涂层的致硬机理。结果表明:Si的掺入影响Zr1-xSixN涂层的择优取向和相结构,随着Zr1-xSixN涂层中Si含量的增加,涂层截面的形貌由柱状晶转变为非柱状等轴晶,其结构的变化为:固溶体→nc-ZrN/α-Si3N4结构→非晶结构。涂层的晶粒尺寸在12～30nm之间。对于Si含量低于3.14%(摩尔分数)的Zr1-xSixN涂层,由于固溶强化作用使硬度随Si含量增加而增大,对于Si含量高于3.14%的Zr1-xSixN涂层,通过晶粒的转动和原子在晶界的移动能产生塑性形变,提高了涂层塑性形变能力,使得硬度下降。Zr1-xSixN涂层的耐磨损性能随Si含量的增加而增强

PREPARATION AND MECHANICAL PROPERTIES OF Zr1–xSixN NANO-COATINGS

第一作者：黄若轩(1984—)，男，硕士研究生。 通讯作者：王周成(1963—)，男，教授。[中文文摘]采用直流与射频共溅射技术制备Zr1–xSixN 纳米涂层。通过改变Si 靶溅射功率控制涂层中Si 含量，研究了不同Si 含量对Zr1–xSixN 涂层的物 相结构、晶粒尺寸、硬度和摩擦磨损性能的影响，探索了Zr1–xSixN 纳米涂层的致硬机理。结果表明：Si 的掺入影响Zr1–xSixN 涂层的择优取向和相结 构，随着Zr1–xSixN 涂层中Si 含量的增加，涂层截面的形貌由柱状晶转变为非柱状等轴晶，其结构的变化为：固溶体→nc-ZrN/α-Si3N4 结构→非晶结构。 涂层的晶粒尺寸在12～30 nm 之间。对于Si 含量低于3.14% (摩尔分数)的Zr1–xSixN 涂层，由于固溶强化作用使硬度随Si 含量增加而增大，对于Si 含量高于3.14%的Zr1–xSixN 涂层，通过晶粒的转动和原子在晶界的移动能产生塑性形变，提高了涂层塑性形变能力，使得硬度下降。Zr1–xSixN 涂层的 耐磨损性能随Si 含量的增加而增强。 [英文文摘]Zr1–xSixN nano-coatings were deposited by direct current and radio frequency co-sputtering from zirconium and silicon. The Si contents in the Zr1–xSixN coating were varied by changing the power applied to the Si target. The influences of Si content on the phase structure, composition, crystal sizes, hardness and tribological properties of Zr1–xSixN coatings were investigated, and the hardening mechanism of the coatings was explored. The results show that the addition of Si significantly affects the orientation and phase structure of Zr1–xSixN coatings. When Si content increased, the cross-section morphology of the coating changes from column structure to non-column structure, the microstructure changes from solid solution to nc-ZrN/α-Si3N4, and then to amorphous. The grain size in the coating is from 12 to 30 nm. When Si adding content is lower than 3.14% in mole, its hardness of Zr1–xSixN coatings increases with the increase of Si content, which is taken as the result of solid solution hardening; while for Zr1–xSixN coatings with the Si contents higher than 3.14% in mole, as a result of atomic sliding in the grain boundaries and grain rotation, its hardness decreases with the increase of Si content. The coatings with higher Si contents have better wear resistance.国家科技支撑计划(2007BAE05B04)资助项目

Influences of Nitrogen Flow Percentage on Microstructure and Hardness of ZrN Nano-Coatings from Magnetron Sputtering

作者简介：黄若轩(1984-),男,硕士生;王周成(联系人),男,教授.[中文摘要]利用磁控溅射方法,通过改变氮气流量制备出ZrN纳米涂层,研究了氮气流量对ZrN纳米涂层结构及硬度的影响,并采用表面轮廓仪、X射线衍射仪、扫描电镜及纳米压痕表征了ZrN纳米涂层的厚度、相结构、形貌及硬度.实验结果表明,随着氮气流量增加,涂层厚度减小,涂层择优取向由(111)变为(200),对应的截面形貌由柱状结构变为非柱状结构;传统的位错滑移机制不适用于ZrN纳米涂层的塑性变形,其硬度随择优取向和晶粒尺寸的增大而增加.[英文摘要]The influences of nitrogen flow percentage on microstructure and hardness of ZrN nano-coatings fabricated by DC magnetron sputtering were investigated.The thickness,phase structure,morphology of cross-section and hardness of ZrN nano-coatings were characterized with profilometer,X-ray diffraction,scanning electron microscope and nanoindentation.The results show that the nitrogen flow percentage significantly affects the thickness and phase structure of ZrN nano-coatings.With increasing nitrogen flow percentage,the coating thickness decreases and the phase structure evolves from the orientation(111) tｏ(200),the cross-secction morphology changes from columnar structure to non-columnar structure as well．For the ZrN nano-coating,the dislocation sliding is not the cause for plastic defomation,and the hardness increases with the increasing grain size and preferred orientation.国家科技支撑计划资助项目(2007BAE05B04