柱弧离子镀制备Ti/TiN/Ti(N,C)/TiC黑色硬质膜

利用自制的柱弧离子镀膜机，在不同硬度基体上制备了Ti／TiN／Ti（N，C）／TiC多层复合膜。膜呈深黑色，反射率小于14％，亮度值L^＊小于43，沉积速率约为0．78μm/h，表面分布较多液滴缺陷。膜的力学性能测试受基体硬度和膜层厚度影响较大，基体越硬、膜层越厚，膜的硬度以及与基体的结合力测试结果越大。YW2硬质合金基体上制备0．82μm的黑色硬质膜显微硬度Hv（25g）=3229，结合力为26．70N。该设备和工艺已成功应用于工业生产。     

工艺参数对Ni-W-P-CeO2-SiO2纳米复合薄膜材料微观组织及性能的影响

通过Ni,W,P和CeO2,SiO2纳米颗粒的脉冲共沉积,在普通碳钢表面制备了Ni-W-P-CeO2-SiO2纳米复合薄膜材料,研究了电解液pH值和电解液温度对纳米复合薄膜材料电沉积过程的影响,采用化学组成、沉积速率、显微硬度和微观组织进行表征.结果表明:增加电解液pH值和电解液温度,纳米复合材料晶粒得到细化,沉积速率和显微硬度增加.当电解液pH值为5.5、电解液温度为60℃时,纳米复合薄膜材料晶粒细小,沉积速率最快,为28.87μm/h,显微硬度最高,为Hv673,若继续增加电解液pH值和电解液温度,沉积速率和显微硬度又开始降低.     

NbN/TaN纳米多层膜的微结构及超高硬度效应

用磁控反应溅射的方法在不锈钢基片上制备了NbN／TaN纳米多层薄膜,试验采用X射线衍射仪（XRD）、透射电子显微镜（TEM）及显微硬度仪对薄膜的微结构和硬度进行分析,结果表明：在NbN／TaN多层膜中,NbN层为面心晶体结构,TaN层为六方晶体结构;NbN／TaN纳米多层膜存在超硬效应,在调制周期2．3～170nm这一放宽的范围内保持超高硬度,硬度最大值HK达51.0GPa     

中阶梯光栅厚铝膜纳米压痕硬度尺寸效应测试与分析

为了明确中阶梯光栅厚铝膜硬度特性,从而为中阶梯光栅刻划刀具晶体结构设计奠定基础,对中阶梯光栅厚铝膜进行了纳米压痕硬度测试与分析,表征了厚铝膜硬度特性。首先,对厚铝膜进行纳米压痕试验并提取了试验数据,采用OP法计算了其硬度值。然后,通过对硬度值的拟合与分析,得出厚铝膜的硬度变化规律与宏观硬度值。实验与分析结果表明:中阶梯光栅厚铝膜在纳米压痕测试过程中会出现尺寸效应(0～0.2μm压深区间),并且不是单一随着压深增大而减小,而是呈现三个明显的变化区域,并且采用AlmasriVoyiadji模型表征了厚铝膜在压深为0～0.2μm区间的硬度变化特性。硬度值在压深为10～15 nm区间再次出现了三个明显变化区域;因此笔者对厚铝膜进行了金相试验与压入过程的接触分析,试验与分析结果表明:10～15 nm压深区域产生这种现象的原因是厚铝膜晶体发生了屈服。本研究具体表征了中阶梯光栅铝膜纳米压痕硬度尺寸效应变化规律,从晶体力学角度解释了极浅压深条件下硬度值变化的原因。     

不同厚度聚氯代对二甲苯膜的结晶与性能研究

在真空气相沉积条件下制备厚度分别为0.32μm、2.39μm、7.98μm和17.11μm的聚氯代对二甲苯膜(PC膜),采用X射线衍射仪(XRD)、原子力显微镜(AFM)和纳米压痕仪对不同厚度PC膜的结晶度、表面形貌以及力学性能进行了表征与测试。结果表明,随着成膜厚度的增加,聚氯代对二甲苯薄膜的结晶度提高,表面晶粒尺寸增大,结晶形态更加完整,其表面粗糙度、压入模量和压入硬度呈逐渐增大的趋势。而PC膜表面形貌、力学性能的差异又与结晶度密切相关。     

对薄膜CrAlTi(Y)N硬度的研究

本文研究了Al靶中加入不同含量的稀土钇（Y）对CrAlTiN薄膜硬度的影响。并应用原子力显微镜（AFM）、能谱仪（EDS）、纳米压入仪、显微硬度计对薄膜样品进行分析。结果表明,CrAlTiN薄膜中稀土元素Y的加入使得灿元素单位时间内沉积量提高,CrAlTiN薄膜晶粒细化,薄膜的表面相由CrN、Cr2N向Cr逐渐变化。当Y〈0．84％时CrAlTiN薄膜的硬度随着稀土Y含量的升高而降低;当Y〉0．84％时CrAlTiN薄膜的硬度随着Y含量的升高而升高。     

马氏体气阀钢多元共渗层的组织及性能

用固体粉末法,在4Cr10Si2Mo马氏体气阀钢表面制备了Al—Cr二元渗层及Al—Cr—Ce三元渗层,研究了渗层的显微组织和成分分布,测定了渗层由表及里的显微硬度。Al—Cr渗层厚度约为3501μm,硬度为580Hv;Al-Cr—Ce渗层厚度约为420μm,硬度为500Hv。     

低硬度薄膜厚度的简易检测方法

介绍了一种检测硬基体上软薄膜厚度的简易方法——显微硬度法。并就射频溅射MoS_2膜的厚度测量与XPS、X射线衍射、表面形貌仪等方法进行了比较。结果表明,此法具有一定的检测精度,可达到一般软薄膜厚度的测量要求。     

选择布氏硬度试验力的经验公式

根据GB231－84标准，布氏硬度试验有2个重要的测试条件，即试样的最小厚度应大于压痕深度的10倍和试验后压痕的直径d应处在0．25D＜d＜0．6D范围内。当压痕直径d—0．375D是最理想的条件，它相当于布氏硬度值HB与试验力F的关系曲线处于平坦区段的中部，此时压入角中一44（o）、维氏硬度利用这个理想条件，选取维氏压头棱面夹角a—136（”），获得较好的相似性。众所周知，试验后压痕直径d的大小与试验力F有直接关系。试验力F愈大，则压痕直径d亦大，反之亦然。在布氏硬度试验中，怎样选择试验力F的大小，使其压痕直径d刚好等于或接近于…     

七种金属基底上类金刚石膜的过渡层制备研究

为了解决类金刚石（DLC）膜在金属基底上附着力低的困难,本研究分别利用了两种厚度不同的Ti/TiCx/DLC过渡层和一种Ti/TiNy/TiNyCx/DLC过渡层在7种金属基底上（W18Cr4V、Cr12、GCr15、TC4、40Cr、9Cr18、1Cr18Ni9Ti）制备了DLC薄膜。利用Si（100）基底镀膜前后的形变,计算的薄膜应力高达3.9 GPa,这种应力在过渡层中部分释放而制备了较厚（0.9μm）DLC膜。薄膜的附着力通过拉拔试验发现,选择合适的过渡层,薄膜的附着力有很大的提高,拉拔中只有胶被拉开。纳米硬度计测试结果表明,薄膜的硬度都在5000 Hv左右,不随基底材料改变。往复式摩擦试验结果显示,稳定后的摩擦系数在0.1附近。通过Raman谱发现,所有基底上薄膜的谱图一致,这说明薄膜的结构不受基底影响。     

On the factors affecting the critical indenter penetration for measurement of coating hardness

The nanoindentation test is the only viable approach to assess the properties of very thin coatings (<1 μm) since it can operate at the required scale and provides a fingerprint of the indentation response of the coating/substrate system. To measure the hardness of the coating only it is traditionally assumed that, as a rule-of-thumb, when the relative indentation depth (RID, i.e. the penetration divided by the coating thickness) is less than 0.1, the substrate will not affect the measured hardness of the coating. However, it is found that this rule is too strict for some and too loose for other coated systems. In this paper we present a comprehensive investigation of the factors influencing the critical relative indentation depth (CRID) using finite element simulation. The CRID is very sensitive to tip radius for soft coatings on hard substrates. For most coating/substrate combinations at reasonable penetration depths the 0.1 rule-of-thumb is a safe estimate. It is shown that the elastic property mismatch between coating and substrate also has an important effect on the measured hardness and this means that the Oliver and Pharr method generally used to extract hardness from nanoindentation data may give inaccurate results in coating/substrate systems with significant elastic mismatch.     

The heat treatment effect on the structure and mechanical properties of electrodeposited nano grain size Ni-W alloy coatings

The Ni-W alloy coatings with tungsten content from 32.5 to 61.2 wt.% were prepared in this study by electro-deposition. Experimental results show that the grain size of Ni-W coatings evaluated by XRD decreased with increasing tungsten content in coatings, however, the micro-hardness increased with increasing tungsten content. As-deposited Ni-61.2 wt.%W coating has amorphous-like structure and the grain size is around 1.5 nm, after annealing at 500 °C, the hardness of the coating is promoted to 1293 Hv owing to formation of Ni₄W and NW precipitates. In addition, the heat-treated Ni-W coatings show a better wear resistance than the as-plated Ni-W coatings.     

The effects of nitrogen bonding on hardness of AIN/CrN multilayer hard coatings

AIN/CrN multilayer hard coatings with various bilayer thicknesses were fabricated by a reactive sputtering process. The microstructural and mechanical characterizations of multilayer coatings were investigated through transmission electron microscope (TEM) observations and the hardness measurements by nano indentation. In particular, the variation of chemical bonding states of the bilayer nitrides was elucidated by near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Many broken nitrogen bonds were formed by decreasing the bilayer thickness of AIN/CrN multilayer coatings. Existence of optimum AIN/CrN multilayer coatings thickness for maximum hardness could be explained by the competition of softening by the formation of broken nitrogen bonds and strengthening induced by decreasing bilayer thickness.     

SiCp/Al复合材料表面电镀Ni-P合金的工艺研究

在高体积分数SiCp/Al复合材料表面镀覆一层Ni-P合金可有效改善其可焊性.为在体积分数60%的SiCp/Al复合材料表面电镀一层Ni-P合金,采用正交试验对电镀工艺参数进行了优化,研究了电镀前预处理工艺,并考察了预处理对电镀层的影响.由正交试验获得了最佳硬度和最佳表面质量的工艺参数;采用SEM、EDS、X射线衍射仪和显微硬度计等对镀层进行表征.研究结果表明:P含量通过影响Ni-P的晶体结构,进而影响其性能,随着P含量(9.38%~15.4%)的增加,Ni-P的非晶态结构越明显,硬度在P含量11.4%时达到最大值723.3 HV;与SiCp/Al表面SiC相上的沉积相比,电沉积Ni-P在Al相上的初始沉积迅速,且长大速度快,导致镀层微观表面凹凸不平.经165℃活化热处理及化学镀18 min后,再电镀40 min,获得的镀层微观表面平整、厚12.90~14.79μm.说明经过优化工艺参数和预处理,可制备表面平整且结合良好的Ni-P电镀层.     

Hardness and indentation-induced damage of SiC-coated graphite

The hardness and indentation damage of chemical vapour-deposited SiC coating/graphite substrate composites have been studied. Experimental results indicate that hardness is a non-linear function of coating thickness, and is not significantly affected by the changes in the magnitude of the residual stresses in SiC coating. The size of indentation lateral crack, observed using optical microscopy, varies with coating thickness. Acoustic emission spectra show that thinner coatings suffer more extensive fracture as compared with thicker coatings.     

2024-T3铝合金硫酸、草酸和酒石酸常温硬质氧化工艺

为寻求节能环保的硬质阳极氧化工艺,以硫酸为基础液外加草酸和酒石酸对2024-T3铝合金进行硬质氧化。研究了供电方式、电解液组分及氧化工艺(温度、电流密度及时间)对2024-T3铝合金硬质阳极氧化膜厚度和硬度的影响,通过SEM,EDS及XRD分析了氧化膜的微观结构和元素组成。结果表明:最佳工艺为10%(体积分数)硫酸,30 g/L草酸,30 g/L酒石酸,采用恒电流法直流叠加脉冲电源,电流密度2 A/dm2,温度15℃,氧化时间50 min;最优工艺下所制备的氧化膜厚度达50μm、硬度达350 HV;氧化膜颜色与混酸中硫酸、草酸浓度及温度有关。     

Tribological Properties of Mo-N Hard Coatings on Ti6Al4V by Double Glow Discharge Technique

Mo-N hard coatings on Ti6Al4V were formed using double glow discharge technique. The fundamental coating properties, such as the phase, hardness and elastic modulus were investigated. The tribological performances of the coatings in dry wear condition were studied by means of ball-on-disc wear machine. The experimental results showed that the thickness of the Mo-N hard coating was about 10 µm. The coating was single fcc γ-Mo2N phase with (200) preferred orientation. The hardness and the elastic modulus of the coating was 13.80 GPa and 261.65 GPa respectively. The surface treatment enhanced the hardness and elastic modulus of the surface of Ti6Al4V base greatly. With GCr15 slider ball, the friction coefficient of the Mo-N hard coating was in the range of 0.56~0.65 at the steady state. Though the coating did not show friction reducing effect, it improved the wear resistance of Ti6Al4V greatly.     

Hard transparent dielectric coatings

Hard transparent corrosion-resistant dielectric coatings were investigated (a) for application to the direct protection of glass surfaces, (b) for application to the protection of thin film metallic window coatings used for reflection or transmission of solar radiation and (c) for use in codeposited metal-ceramic coatings. The dielectric coatings were Al₂O₃, SiO₂ and SiC in the thickness range 100–100 000 Å. The coatings were deposited under varying conditions of substrate temperature, gas composition, r.f. power and substrate preparation. The results of the following measurements on the dielectric coatings are presented: diamond pyramid hardness tests, optical reflectance and transmittance in the region 0.6–4.0 eV and corrosion resistance tests under cyclic conditions. The results showed a considerable improvement in the scratch resistance and hardness of glass by layering of hard dielectric coatings 2–5 μm thick.     

超音速电弧喷涂Ti-Al涂层抗滑动磨损性能研究

采用二次正交回归试验设计原理和钛铝双丝超音速电弧喷涂Ti-Al合金复合涂层方法，对LY12铝合金进行了表面强化研究，并采用金相、XRD、SEM、硬度和磨损试验方法，对涂层的组织结构及力学性能进行了表征，考察了喷涂工艺参数对涂层孔隙率、显微硬度和耐滑动磨损性能的影响，研究结果表明：在本文的实验条件下，涂层的体积磨损量、孔隙率、显微硬度与喷涂电压和喷涂距离之间的变化规律，可用回归模型进行描述；随喷涂电压的增大，涂层磨损量逐渐下降；喷涂距离小于220mm时，随喷涂距离的增大涂层磨损量逐渐增大；喷涂距离为220mm时，磨损量达到最大，继续增加喷涂距离，涂层的磨损量逐渐下降；在干摩擦条件下，Ti-Al合金涂层的磨损机制主要以化合物相剥落引起的磨粒磨损和氧化磨损为主。