H13钢等离子渗氮-类金刚石膜(DLC)复合处理的性能研究

研究了等离子渗氮-离子镀类金刚石膜复合处理工艺与未氮化离子镀类金刚石膜处理工艺对H13钢表面性能的影响.结果表明,经过等离子渗氮后镀类金刚石涂层复合处理的H13钢表面硬度、膜/基结合强度、耐磨性能等均优于未氮化镀类金刚石涂层的样品.     

真空阴极电弧沉积法沉积类金刚石膜在扬声器振膜上应用的研究

采用真空阴极电经反沉积技术，在纯钛球顶高音声声器振膜上镀类金刚石膜，为成类金刚石／钛复合振膜。研究了钛基体的材质、厚度、振膜的几何尺寸和形状、类金刚石镀膜工艺参数对复合振膜性能的影响。在镀膜过程中采用特殊的辅助夹具以及合理的遮挡技术，保证振膜不变形和最佳的类金刚石膜层厚度分布，使类金刚石／钛复合振膜的频响达到３０ｋＨｚ，并且能实现批量生产。     

活塞环用CrN膜层摩擦磨损性能研究

采用阴极电弧离子镀技术沉积了厚度为20μm左右的CrN膜层,分别用扫描电镜(SEM)、显微硬度计、划痕仪,分析测试了CrN膜层的表面和截面形貌、膜层厚度、硬度、结合力等性能.用专用珩磨机模拟活塞环在气缸内的运动,对比了氮化+CrN活塞环与普通氮化环在极端情况下的磨损特性.结果表明:采用阴极电弧离子镀方法制备的CrN膜具有良好的综合性能,膜层界面明晰、结构致密,膜层与基体结合力大于100 N;氮化+CrN活塞环的表层磨损量仅为普通氮化环的1/7,表现出极佳的耐磨性.     

等离子体刻蚀处理对金刚石膜结石性能影响的研究

研究了一种特殊的前处理工艺,即原位氩－氢等离子体制蚀,对金刚石膜与硬质合金基体结构性能的影响,结果表明江 氩－氢等离子体刻馒有明显地粗化基本表面,改变表面的化学成分,并形成一层纯钨层。当这层纯钨层在后续的工艺中被再次碳化后,金刚石膜与与基体的结合结构得到明显提高。     

低温离子渗氮对16Cr3NiWMoVNb齿轮钢摩擦学性能的影响

齿轮作为航空发动机的主要传动部件之一,在服役过程中齿面易发生磨损失效,无法完全满足航空发动机的需求,因此采用表面处理的方法来提高航空齿轮钢磨损性能。对16Cr3NiWMoVNb齿轮钢表面进行低温离子渗氮处理,通过扫描电子显微镜、X射线电子能谱仪等分析了不同电压对其表面组成及结构、硬度、摩擦学和耐腐蚀性能的影响。结果表明：等离子渗氮处理后在16Cr3NiWMoVNb齿轮钢表面形成了间隙固溶体,经900 V电压渗氮处理后的表面硬度由原来的269 HV提高到325 HV,且渗氮后的样品截面硬度呈现下降的趋势,其磨损率相比原样品降低了近50%;在质量分数为3.5%的NaCl溶液中,渗氮后试样的阳极极化曲线呈现出活化溶解、自钝化等特征,经850 V电压处理后腐蚀电位由未渗氮的-726.18mV提高至-410.68 mV,耐腐蚀性能得到显著改善。因此,对航空用齿轮钢,采用低温离子渗氮表面处理的方法可提高其耐磨性和耐腐蚀性。     

等离子喷涂微米和纳米Al2O3-13wt，TiO2涂层的防护性能

以微米和纳米Al2O3-13wt%TiO2为粉末材料,采用大气等离子喷涂在Q235钢基体表面制备了Al2O3-13wt%TiO2涂层,对涂层的显微结构、相组成和显微硬度等基本性能进行了表征,并对两种涂层的耐SiC砂粒磨损和耐电化学腐蚀防护性能进行了对比研究.结果表明,与微米粉末相比,纳米粉末作为热喷涂材料需要更高的喷涂功率才能获得致密的纳米和微米复合涂层;纳米粉末制备的涂层的显微硬度、耐砂粒磨损和电化学腐蚀性能均明显优于微米粉末制备的涂层,表明纳米粉末制备的涂层具有更优良的防护性能.     

金刚石表面金属化（镀膜）的试验研究

利用化学镀和真空镀 2种方法对金刚石表面进行金属化处理的试验研究结果表明 ,镀膜金刚石较未镀膜金刚石的抗压强度、热稳定性等性能和碎岩效果均有很大提高 ,其中真空镀Ti的效果最好。真空镀Ti-Cr金刚石表面上形成的碳化物TiC、Cr2 C3等中的C可能来自金刚石本身。真空镀是一种很有前景的金刚石表面处理方法。     

甲烷浓度对金刚石膜表面形貌及其热导率的影响

以甲烷为碳源气体,用直流等离子射流法制备了金刚石膜.研究了不同甲烷浓度对金刚石膜的表面形貌和热导率的影响.结果表明,在甲烷浓度φ(CH4)为1.5%时,可以获得较高热导率的金刚石膜.     

YG6硬质合金表面火焰法沉积纳米复合碳涂层

采用火焰法在抛光的YG6硬质合金表面沉积碳涂层,用扫描电镜、X射线衍射及显微激光拉曼光谱等分析手段对其形态及结构进行了表征.结果表明,在火焰内焰长度为50 mm、基体离火焰喷嘴距离为30 mm、沉积温度约850℃、沉积时间为1 h的工艺条件下,可制备出纳米类球状金刚石聚晶和类金刚石复合碳涂层.     

等离子喷涂碳化钛-硅化钛涂层的组织结构与性能

研究直接喷涂和反应喷涂合成的两种碳化钛-硅化钛复合涂层的组织结构与性能.通过等离子喷涂技术将两种不同复合粉(TiC-TiSi₂和Ti-SiC)分别喷涂在TC4钛合金表面制备成碳化钛-硅化钛复合涂层,利用X射线衍射仪、扫描电子显微镜、万能拉伸试验机、显微维式硬度计、划痕仪对所得涂层进行表征及测试.结果表明:等离子喷涂TiC-TiSi₂复合粉所得涂层中含TiC为58%,Ti₅Si₃为21%,TiSi₂为7%,Si为9%和SiO₂为5%,等离子喷涂Ti-SiC复合粉所得涂层含有TiC(47%),Ti₅Si₃(40%)和SiC(13%);在等离子喷涂过程中Ti-SiC复合粉中的Ti与SiC发生了明显的化学反应,反应生成了TiC和Ti₅Si₃;等离子喷涂Ti-SiC复合粉所得涂层,具有更薄的层片和更小的晶粒尺寸.与等离子喷涂TiC-TiSi₂复合粉所得碳化钛-硅化钛涂层相比,等离子喷涂Ti-SiC复合粉所得碳化钛-硅化钛涂层具有更高的结合强度、更高的显微硬度(提高了18.7%)、更好的韧性及更好的耐划痕性能,这主要在于等离子喷涂Ti-SiC复合粉反应合成的碳化钛-硅化钛涂层中硬质相的相对含量更高且反应合成的碳化钛、硅化钛晶粒更细小.     

The influence of bias and in-situ cleaning on Through Cage (TC) or Active Screen Plasma Nitrided (ASPN) steels

The effect of a substrate bias and prenitride plasma etching on the nitriding response of four steel substrates is investigated in a two factor two level full factorial experimental design. The steels investigated were P20 (M200, Plastic mould steel), H13 (W302, Hot-work tool steel, as received), 4140 (Preheat treated nitriding steel) and 1020 (CS1020, Bright mild steel). The nitriding response was determined from surface and cross-sectional hardness measurements. Nitrogen depth profile measurements were obtained using Glow Discharge Optical Emission Spectroscopy. — Considering the main effects, the results show that without worktable bias during the nitriding step there is effectively little or no nitriding response in most of the materials. The prenitride plasma etch did not produce a significant surface hardness response in all steels except H13, where a prior etch substantially increased surface hardness and influenced the hardness depth profile. The bias significantly increased the nitrogen wt%. The plasma etch also influenced the near surface nitrogen wt% concentrations, however, the practical implications of this require further investigation.     

A fundamental contribution to a study of the active screen plasma nitriding process

Active Screen Plasma Nitriding (ASPN) is a novel plasma based nitriding process which challenges many of the existing hypotheses concerning mass transfer in plasma nitriding and, in turn, questions the influence of substrate bias during nitriding. In this study, a Field Emission Gun Scanning Electron Microscope analysis was used to investigate material transfer from the active screen. The results demonstrate that material transfer and deposition, in the form of nano-particles, take place from the active screen to parts that are in a direct line of sight of the active screen. The nano-particle distribution is significantly influenced by the type of active screen material used and the application of substrate bias. However, the suggestion that the mechanism of mass transfer in ASPN is directly related to sputtering of material from the active screen is questioned by the observation that AISI H13 steel samples treated in a non line of sight position in the ASPN chamber showed a significantly higher nitriding response than AISI H13 samples treated in direct line of sight of the active screen.     

QPQ处理工艺对F690钢渗层微观结构及磨蚀性能的影响

利用QPQ技术对F690海工钢进行盐浴复合强化处理,考察了碳氮共渗温度和时间对F690钢渗层组织、相结构及硬度、腐蚀磨损性能的影响。结果表明:经过QPQ处理后,F690钢表面形成由Fe₃O₄氧化层、Fe₂C/Fe₂N化合物层及扩散层组成的渗层,且渗层组织平整均匀。随着QPQ处理温度升高和时间延长,渗层厚度增加,渗层硬度均呈先增大而后减小的变化规律;当共渗温度为570 ℃、时间为60 min时,F690钢的渗层硬度达854HV,较F690钢硬度提高1.7倍。与F690钢相比,3.5%NaCl介质下渗层的自腐蚀电流密度降低了一个数量级,腐蚀速率降低了86.71%,摩擦系数下降约12%,磨损率显著降低。     

压铸模具的热处理工艺

通过工艺试验及生产验证,4Cr5MoSiV1钢压铸模具经过气体氮化处理后具有高的热稳定性、表面硬度高、耐磨性好、脆性低、心部强度高和热处理变形小等优点,是气体氮化适用的钢种。     

钛涂层接骨板的生物和力学性能的研究

采用低压等离子喷涂工艺，在３１７Ｌ不锈钢质接骨板上喷涂了钛涂层，制备出钛涂层的接骨板，通过动物的植入试验，研究了这种骨板的生物相容性，利用扫描电镜，电子探针，Ｘ射线衍射仪等分析仪器对涂层的微观结构，涂层－基体界面成分分布等进行了研究，同时也对涂层接骨板的电化学性能进行了研究，结果表明，喷涂过程对不锈钢质接骨板本身的冶金能影响很小，钛涂层结合良好，其与骨组织的生物相容性能优于未涂钛层的不锈钢接骨板。     

HVOF和APS喷涂WC-10Co-4Cr涂层性能研究

以45号钢为基体分别采用超音速火焰喷涂(HVOF)和大气等离子喷涂(APS)法,制备了两种WC-10Co-4Cr涂层,并对两种工艺喷涂的WC-10Co-4Cr涂层进行了金相显微结构分析、结合强度及硬度测试.试验结果表明:HVOF和APS制备的WC-10Co-4Cr涂层金相组织分布均匀,界面结合致密无杂质;HVOF制备的WC-10Co-4Cr涂层的孔隙率较小,且显微硬度及结合强度均优于APS的.表明,HVOF制备的WC-10Co-4Cr涂层的基本性能优于APS制备的WC-10Co-4Cr涂层.     

煤矿井下采掘机械齿轮选材及其综合性能的探讨

煤矿井下的环境与地面完全不同，受到了作业空间和地质条件等方面诸多因素的制约。采掘机械的齿轮是其核心零件，是决定其综合性能优劣和工作寿命长短的关键因素。目前，我国齿轮的制造工艺和技术虽有了很大的进步和发展，采掘机械齿轮的制造精度已提高到了6～7级，但齿轮的寿命约为国外先进国家齿轮寿命的一半。现在     

硬质合金刀具的类金刚石涂层的研究

采用优化的沉积类金刚石（DLC）涂层工艺及过渡层技术,在硬质合金上制备出性能优良的DLC膜,实验室切削试验与工业生产现场切削表明：在切削铝青铜和共晶铝硅合金时,DLC膜涂层刀具使用寿命明显高于末涂层刀具。     

双层辉光离子渗Cr合金层组织和性能

在Q235钢表面进行双层辉光离子渗Cr，表面Cr含量约为40％，渗层厚度近50 μm.然后进行超饱和渗C，表面含C量达到2.7％左右，超过平衡碳计算值.随后进行淬火＋低温回火处理，经X射线衍射分析，合金化层碳化物类型为M23C6，M7C3，尺寸为1～2 μm.表面硬度达到HV 1 200左右.将表面冶金试样进行摩擦因数和耐磨性能试验，结果表明，表面冶金试样摩擦因数为0.21～0.28，耐磨性是Q235钢渗碳淬火试样的1.62倍.将表面冶金试样在10％的H2SO4、3.5％的NaCl水溶液和H2S富液（含H2S 5～8 g/L，NH3·H2O 20 g/L）中进行电化学腐蚀试验，结果表明，表面冶金试样在10％的H₂SO₄、3.5％的NaC1水溶液和H2S富液中的耐腐蚀程度比Q235基体试样分别提高了2.35，3.10，2.14倍.     

Low temperature plasma surface alloying of medical grade austenitic stainless steel with carbon and nitrogen

Low temperature surface alloying with either nitrogen (nitriding) or carbon (carburizing) has been successfully employed in hardening AISI 316. However, little work has been directed towards low temperature plasma surface alloying with both nitrogen and carbon simultaneously. In addition, little or no research has been conducted on the surface modification of medical grade austenitic stainless steels, such as ASTM F138 and F1586. In this study, plasma surface alloying treatments have been conducted on medical grade ASTM F138 and ASTM F1586 as well as on engineering grade AISI 316 for comparison. Systematic materials characterization was carried out using optical microscopy, GDOES and XRD. The surface properties such as hardness, wear and corrosion of the modified surface layers were evaluated. Based on the results, the response of these materials to simultaneous plasma surface alloying with both nitrogen and carbon is compared with nitriding and carburizing processes.