Ti合金化DLC膜的结构和力学性能

在一台увнипА－1型双激发源等离子弧薄膜沉积装置上制取Ti合金化DLC膜，用纳米硬度计、显微硬度计、原子力显微镜以及X射线衍射仪和光电子能谱仪等手段对薄膜的力学性能和结构进行了分析和测定。摩擦磨损试验在一台球－盘滑动磨损试验机上进行。比较了不同钛合金化程度的DLC膜及热处理前后的性能变化。结果表明，薄膜的力学性能与Ti含量有非单值关系，但摩擦系数随Ti含量增加而升高；热处理后薄膜显微硬度显著升高的原因是生成了碳化钛硬化相。     

FCVA法沉积的超薄类金刚石薄膜的结构与热稳定性

采用FCVA方法沉积了厚度分别为2nm、5nm、10nm和30nm的类金刚石薄膜.在氩气保护下对类金刚石薄膜进行了180、300、400和600℃,保温6h的退火处理.用Raman光谱和宽光谱变角度椭偏仪研究了DLC薄膜的结构和热稳定性.实验结果表明,随着薄膜厚度增大,FCVA法沉积的DLC薄膜中的sp3键含量增加,薄膜热稳定性逐渐改善.当DLC薄膜的厚度为30nm时,薄膜中的sp3键含量达到最高值,薄膜具有最好的热稳定性.当退火温度为600℃时,厚度为2nm和5nm的DLC薄膜结构由非晶态转变为微晶态;厚度为10nm和30nm的DLC薄膜结构发生转变但仍保持非晶态.随着退火温度的升高,各个厚度的DLC薄膜的光学带隙Eg均先增大后减小.     

类金刚石薄膜中杂质Fe对其力学性能的影响

描述了利用射频等离子体溅射法采用不同阴极在衬底Ｓｉ片上形成类金刚石薄膜的杂质含量及杂质对厚度和硬度的影响分析与结果,比较了ＤＬＣ膜的力学性能在有无金属杂质情况下的异同,分析和计算了其硬度与硬度与制备参数间的关系,得出利用石墨作电极能制备出质量较好的ＤＬＣ膜,初步探讨在Ｓｉ衬底上沉积高硬度和强附着度类金刚石薄膜的有关工艺条件,并在理论上对这一结果进行了解释。     

基体偏压对中频磁控溅射沉积DLC膜结构的影响

利用中频非平衡磁控溅射技术,以氩气和甲烷混合气体为工作气体,在载玻片和单品硅片上沉积含氢的类金刚石簿膜.改变加载在基体上的负偏压,在0～400 V范围内,制备5种偏压值下的薄膜,研究偏压对薄膜结构的影响.用光学显微镜和AFM考察薄膜的光学形貌;激光Raman谱定性分析膜的化学组分;VFIR分析其C-H键合类型;纳米压痕法测量膜的硬度.结果表明:当基体上施加偏压-100 V时,可以有效地提高沉积粒子与基体结合力以及溥膜的致密性,薄膜中正四面体的sp3结构和sp3CHn含最增加,纳米硬度提高.     

退火温度对DLC膜热稳定性及摩擦学性能的影响

采用非平衡磁控溅射技术分别在氮化硅陶瓷球和高速工具钢圆盘表面制备了类金刚石(DLC)膜。使用箱式电阻炉对DLC膜在大气环境中进行高温退火处理以研究环境温度对DLC膜摩擦学性能的影响;并分别采用激光拉曼光谱仪和球-盘式摩擦磨损试验机对退火处理前后DLC膜的结构和摩擦学性能进行了研究。采用金相显微镜观察了摩擦副磨损表面的形貌。研究发现,随着退火温度的升高,DLC膜中sp3杂化键向sp2杂化键的转化加快,当退火温度为600℃时,DLC膜发生严重的石墨化。而当退火温度为400℃时,DLC膜的摩擦系数及磨损率最小。拉曼测试表明400℃退火处理后DLC膜表层含有Si及SiO2,在摩擦过程中形成了含SiC的转移膜,使得DLC膜的摩擦系数明显降低,磨损减小。研究结果表明,退火处理对DLC膜的热稳定性和摩擦学性能有重要的影响。     

SiC/DLC过渡层对类金刚石薄膜力学性能的影响

采用等离子体浸没离子注入及沉积技术在钛合金(Ti6Al4V)表面制备了类金刚石薄膜和含有SiC/DLC过渡层的类金刚石薄膜。采用拉曼光谱及扫描电子显微镜分析了薄膜的成分和结构,并利用超显微硬度计、薄膜结合力测试仪和往复式摩擦实验机研究了薄膜的硬度、韧性、膜/基结合力和耐磨性。研究结果表明,SiC/DLC过渡层可以提高钛合金(Ti6Al4V)表面类金刚石薄膜的韧性及膜/基结合力,与未制备过渡层的类金刚石薄膜相比,含有SiC/DLC过渡层的类金刚石薄膜的耐磨性明显提高。     

类金刚石（DLC）膜的制备技术概况

综述了类金刚石膜的制备方法，以及各种制备方法的基本原理和特点，并分析了各种方法对膜的结构和性能的影响。     

铝合金表面DLC薄膜中间层对磨损性能的影响

为了改善铝合金表面磨损特性,采用离子镀方法在8种不同类型的铝合金表面制备了类金刚石(DLC)薄膜,DLC沉积之前,用磁控溅射方法和离子镀方法在铝合金表面沉积Ti,SiC和VMS 3种不同的中间层;用球-盘磨损试验机对涂层材料磨损性能进行了表征。结果表明:铝合金表面DLC薄膜的摩擦系数约为0.2～0.3,不同的铝合金,随中间层的不同具有不同的磨损效果,中间层对DLC薄膜的磨损性能影响明显,中间层为SiC的6061铝合金表现出最好的摩擦磨损特性。     

RF-PECVD工艺参数对DLC膜结构及性能的影响

用射频等离子增强化学气相沉积(RF-PECVD)法,在常温下实现在载玻片和单晶硅基片上沉积类金刚石(DLC)薄膜。研究结果表明,工艺参数(功率密度、氩气分压、丁烷分压和极间距)的变化对薄膜硬度和透过率影响较大。薄膜硬度随着功率密度的增加而增加;随着氩气分压或丁烷分压的增加,薄膜硬度降低。薄膜的透过率随着氩气分压先增后减;丁烷分压为0.42～0.7Pa或板极间距为4.5～8cm时,薄膜的透过率均达到90%。     

DLC薄膜中sp2键含量对HUVEC细胞附着性能的影响

本文利用具有特殊的电子结构的类金刚石(DLC)薄膜来研究材料表面电子结构对人脐静脉内皮细胞(HUVEC)附着性能的影响。采用直流电弧脉冲等离子体沉积法制备DLC薄膜,通过改变靶室气体种类和气体压强来控制DLC薄膜中sp2键的含量,并通过Raman光谱分析法进行测定。采用DAPI免疫荧光染色法对细胞附着形态进行观察,并利用ImageJ对随机记录的多个视场的所有细胞进行了细胞附着形态的统计学分析。实验结果表明:在充入Ar气制备的DLC薄膜表面,内皮细胞的附着性能随着sp2键含量的升高而变差,充入Ar/C2H2混合气体制备的DLC薄膜因所有细胞附着形态均很差而未体现出随sp2键含量而变化的明显趋势。     

Ce添加对Mg–Ca挤压合金力学性能与热稳定性影响研究

目的 研究在Mg–0.2Ca挤压合金基础上分别添加质量分数为0.3%的Ce和0.6%的Ca后对合金的组织、力学性能和热稳定性的影响,探究Ce和Ca 2种合金元素对镁合金的强化和中高温条件下的稳定化效果。方法 首先,熔炼制备Mg–0.2Ca、Mg–0.2Ca–0.3Ce和Mg–0.8Ca 3种成分的合金;随后,对3种合金进行挤压变形,并对挤压合金组织和力学性能进行表征和测试;最后,在300℃下对3种合金进行等温退火,研究其组织演变过程和力学性能的衰减情况。结果 在Mg–0.2Ca合金基础上添加质量分数为0.3%的Ce可将挤压态合金再结晶分数由约92%降至约53%,再结晶晶粒尺寸由约1.64μm细化至约0.86μm,Mg–0.2Ca–0.3Ce三元合金的屈服强度可大幅提升至约364 MPa,该屈服强度与Mg–0.8Ca合金相当（约361 MPa）,表明单位质量Ce的添加对强度提升的效果优于Ca。退火3 h后,Mg–0.2Ca–0.3Ce三元合金屈服强度的下降幅度约为124 MPa,显著低于Mg–Ca二元合金（约170 MPa）。以Mg–0.2Ca–0.3Ce合金为例进行静态再结晶组织演化分...     

Structural, Mechanical Properties and Thermal Stability of ZrAlN Coatings

Dry machining will result in elevated temperatures at the tool surface ( 800 ～ 1000 ℃ ). So, coating materials that can provide protection for cutting tools at these temperatures are of great technological interests. ZrAlN coating is proposed to possess high-temperature stable structural and mechanical properties due to the addition of the alloying element.ZrAlN coatings were grown using a dc reactive magnetron sputtering. The XRD and ultramicro-indentor were employed to investigate the effects of reaction gas partial pressure and substrate bias on structural, mechanical properties, as well as hightemperature stability. The ZrAlN coating, when deposited under optimum conditions ( -37 V substrate bias and 1.5 10-7 Torr N2 partial pressure), showed smooth surface with 22 GPa hardness and 2.2 GPa internal stress. Its structural and mechanical properties kept high-temperature stability before and after annealing .     

类金刚石薄膜的耐热性研究进展

类金刚石薄膜具有良好的物理化学性能、光电性能、机械性能及摩擦学性能。但是在高于400℃的温度条件下，DLC膜易向石墨结构转变，从而阻碍了其在高温条件下的应用。因此关于类金刚石薄膜耐热性的研究是目前的一个热门研究课题。在综合分析近年来该领域研究的基础上总结了影响DLC膜耐热性的3种因素：膜结构、掺杂、制备方法，并分析了各种因素的影响机理。     

Effect of Nonmetallic Inclusions on the Mechanical Properties of Hydrogenated Steels

We have studied intermediate-alloy Ni-Cu-Mo-V steel of open-hearth and converter (more pure as to nonmetallic inclusions) melting. In the case of middle hydrogen concentrations (up to 5 cm³ per 100 g), the strength characteristics, plasticity, and fracture energy of transverse and vertical specimens of converter steel decrease less than those for open-hearth steel. For higher hydrogen concentrations, the characteristics of steel become very low and almost identical for both materials. Under loading, cracks are initiated on nonmetallic inclusions; in hydrogenated steel, they propagate along the shortest path from one inclusion to another, without involving significant volumes of the specimen in plastic deformation. We have established that nonmetallic inclusions accelerate crack initiation under conditions of corrosion in pipe steels in the course of operation of pipelines.__________Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 40, No. 6, pp. 115–119, November–December, 2004.     

相容剂对阻燃剂/聚丙烯体系热性能及力学性能的影响

选用丙烯酸接枝聚丙烯(PP-g-AA)、马来酸酐接枝聚丙烯(PP-g-MAH)及N-羟甲基丙烯酰胺接枝聚丙烯(PP-g-NMAM)3种相容剂来改善聚磷酸铵/季戊四醇膨胀型阻燃剂(IFR)与聚丙烯的相容性。力学性能和扫描电镜(SEM)分析结果表明,PP-g-MAH/PP/IFR具有较好的相容性及力学性能,能较好地解决阻燃剂在聚丙烯体系中的团聚现象。氧指数(LOI)和垂直燃烧UL94测试结果表明,相容剂的加入对PP/IFR体系的燃烧性能影响不大,PP-g-MAH效果最佳,加入10%的PP-g-MAH,IFR的含量为30%时,LOI达到32.8%,UL94测试达到V-0级。热分析发现,季戊四醇和聚磷酸铵是通过酯化反应成炭而形成一层保护膜,保护膜起到隔热隔氧的作用而阻燃。     

热障涂层（TBC）稳定性的研究EI

将ＺｒＯ_２·８％Ｙ_２Ｏ_３用射频磁控溅射技术沉积在ＮｉＣｒＡｌＹ底涂层上，进行ｌｌ００℃→室温，１１００℃→冷水和９００℃→室温等热周期和熔盐作用的试验。随后进行Ｘ－射线衍射（ＸＲＤ）分析和扫描电镜（８ＥＭ）观察。结果表明，沉积态的氧化锆层主要为立方相和少量单斜相及四方相。热周期及熔盐Ｎａ_２ＳＯ_４－５％ＮａＣｌ与ＺｒＯ_２·８％Ｙ_２Ｏ_３的化学作用都促使立方相→单斜相的转变。熔盐对晶界和底涂层的化学和物理的作用是影响涂层稳定性的另一因素。     

Effect of Phosphorus on Mechanical Properties and Thermal Stability of Fine-grained GH761 Alloy

The effect of phosphorus on mechanical properties and thermal stability of fine-grained GH761 alloy has been investigated.The results show that,when the content of phosphorus is in the range of 0.0007-0.040,there are no significant effects on the tensile properties.Phosphorus strongly affects the stress rupture life.The content of 0.023 P results in the longest life in this experiment.Compared with that of the alloy with 0.0007 P,the life is increased more than 2 times in the alloy with 0.023 P.After ageing at 700℃ for 1000 h,the life reduced to some extent.However,phosphorus exhibits the similar effect on the life as before ageing.The tensile properties of the alloy are not influenced by long term ageing obviously.The present results suggested that the optimum content of phosphorus is 0.023.The phosphorus with this content can optimize the precipitates at the grain boundaries and prevent the excessive growth of the precipitates.The combining mechanical properties of GH761 alloy can be largely improved by phosphorus addition combined with grain refinement.     

Thermal Mechanical Fatigue Behavior of Advanced Overlay Coatings

Environmental protection and cost effectiveness lead to the demand to increase the efficiency of energy conversion. In the past decade gas turbines have become an important factor in efficient power generation. Gas turbine inlet temperatures are being increased continuously to decrease the specific fuel consumption. The development of new base materials and sophisticated processes like single crystal solidification allows higher metal temperatures. This causes higher oxidative stress to the MCrAlY overlay coatings. As shown in an earlier paper (I), an improvement of the high temperature properties is achievable by the addition of Rhenium. In this paper we report on properl ies of MCrAlY coatings containing 8 to 12% Al and 10% Rhenium by weight. The coatings were applied on Inco 738 LC by LPPS (Low Pressure Plasma Spraying). Data for static oxidation and cyclic oxidation data at 950°C, I000°C up to 10,000 hours are presented. However, the main aim of this report is to discuss the thermal-mechanical properties of LPPS-coatings with Re. As known from earlier work, the variation or addition of different elements to overlay coatings lead to a change in the ductile-brittle transition. Ductile-Brittle-Transition-Temperature (DBTT) measurements on 10% Re containing systems under the variation of Co, Cr, Al and Si have been done. In order to get more information about the thermal-mechanical properties of the coating under service like conditions, TCF (Thermal Cycle Fatigue) and TMF (Thermal Mechanical Fatigue) tests were carried out. On discus shaped samples, the TCF behavior of an MCrAlYRe coating in comparison to an MCrAlY coating has been evaluated up to 1,500 cycles. The samples were heated in a radiation oven up to 1000°C and cooled down by compressed air. By this method a differentiation in the thermal fatigue behavior is possible. However, this kind of test does not cover all possible relaxation processes. A more realistic investigation of the thermal mechanical fatigue behavior is given by TMF tests. A service life cycle was taken to study the thermal mechanical behavior. It is shown that Re improves the thermal mechanical properties of MCrAlY coating systems considerably.