Cr35Ni45Nb钢铝硅共渗涂层抗渗碳性能研究

对乙烯裂解炉管材料Cr35Ni45Nb钢进行铝硅共渗处理。对处理后试样进行观察分析,渗层由渗剂残留组成的粘附层、互扩散层和连续白亮的渗层组成共渗。处理后基体硬度没有变化。对未进行铝硅共渗处理的试样渗碳处理,发现试样出现约40μm渗碳层,基体分布着碳化物颗粒。而铝硅共渗处理后的试样渗碳后,碳化物颗粒均分布在渗层,渗碳层硬度约为20μm,基体内无碳化物颗粒。因此铝硅共渗处理提升了材料的抗渗碳能力。     

Mo合金高温抗氧化涂层的研究

用粉末固体渗法在钼合金表面制备了MoSi2渗层,研究了铝硅共渗和硼硅共渗对渗层的结构和抗氧化性能的影响.结果表明,与渗硅相比,铝硅共渗层厚度保持不变,渗层由单层结构变成多层复合结构,抗氧化性下降;硼硅共渗层厚度减少,结构没有明显改变,抗氧化性能得到了明显改善.     

交流电场对45钢粉末法铝硅共渗的影响

通过一对平行电极对45钢试样与渗剂施加交流电场,进行交流电场增强粉末法铝硅共渗。通过分析对比电场增强粉末法铝硅共渗与常规铝硅共渗渗层的厚度、组织、微区成分、相结构及抗氧化性能,研究电场对45钢粉末法铝硅共渗的作用特性。结果表明:交流电场能够显著促进粉末法铝硅共渗,渗层厚度和硅含量随电场强度增加而增加,渗层相结构也发生相应变化,当渗扩温度≥650℃、电场电流≥0.5 A时,富铝相消失;常规工艺700℃共渗4 h的渗层厚度仅约24μm,但在电流为0.7 A的电场作用下,可获得约100μm厚渗层;900℃循环氧化试验表明,电场铝硅共渗试样的抗氧化性能远高于常规铝硅共渗试样。     

用耐火粘土,三氧化二铬和铝粉进行钢纤维的铝铬硅三元共渗

用耐火粘土（６０％ＳｉＯ２）、三氧化二铬和铝粉对Ｑ１９５低碳钢纤维进行铝铬硅三元共渗处理，共渗层具有很高的抗高温氧化和耐蚀防锈性能。     

预氧化对铝—硅渗层抗热腐蚀性能影响的研究

在涂渗与扩散两工序之间进行950℃/30min的预氧化处理可以大幅度提高ASL系列3型铝硅渗层的抗热腐蚀能力,而对渗层/基材系统的力学性能则无任何损害。 分析证明,预氧化处理使这类铝-硅渗层的表面形成一层致密的,且铝、硅含量较高的氧化膜,其中二氧化硅的存在使氧化膜具有优越的抗热腐蚀性能。     

钛铝基合金渗硅层结构及抗高温氧化性能初探

研究了钛铝基合金固体渗硅后的渗层结构、抗高温循环氧化性能。结果表明：钛铝基合金固体渗硅后表层形成主要由Ti5Si3、Al3O3和Al3Ti、TiSi2、Si构成的复合渗层，该复合渗硅层有效阻止了高温氧化过程的进行，显著提高了钛铝基合金的抗高温循环氧化能力。     

化学成分对奥氏体耐热钢抗渗碳性能的影响

本文通过固体渗碳实验方法,研究了Ni、Si和Nb等合金元素对奥氏体耐热钢抗渗碳性能的影响规律。结果表明:Ni、Si或Nb均提高耐热钢的抗渗碳能力。其中Ni和Si主要通过阻碍渗层碳化物的形成而降低渗层碳浓度。Nb既即可通过表面氧化膜的作用,限制碳向钢中扩散,降低渗层碳浓度;有时又可能提高渗层碳浓度,降低渗层厚度的增长速率。     

3Cr2W8V钢制模具的热处理与强化方法及应用

综述了3Cr2W8V钢制模具的热处理研究方法及应用实例。3Cr2W8V钢可采用淬火、回火处理，渗碳、渗氮、渗硼及碳氮共渗、渗铝、渗铬及铬—铝—硅三元共渗等化学热处理，镀金属等表面强化处理来提高其高温强度、冷热疲劳抗力、耐磨性、抗腐蚀性及防粘模等性能，从而达到提高3Cr2W8V钢制模具的使用寿命的目的。     

稀土化学热处理进展

综述了哈尔滨工业大学稀土化学热处理研究和应用成果。包括稀土渗碳及碳氮共渗、稀土渗氮及氮碳共渗、等离子体稀土渗氮、稀土渗硼及硼铝共渗、稀土多元共渗、稀土渗金属工艺技术，稀土的催化和微合金化机制，渗层组织和性能的改善，稀土化学热处理在生产中的应用及其过程的数学模型与计算机仿真等。     

碳氮共渗预处理对渗硼层组织性能的影响

研究了碳氮共渗对16Mn钢渗硼层组织结构和性能的影响。结果表明，碳氮共渗预处理使渗硼层的组织、显微硬度分布、脆性、耐磨性比单一渗硼层有明显的改善。碳氮共渗预处理可以得到具有较强支撑作用的过渡层，从而使耐磨性提高。通过复合渗处理的灰砂砖模板，其使用寿命可提高2～3倍。     

输入轴的防渗碳涂料自动涂敷设备设计开发和应用

通过设计开发输入轴防渗碳涂料自动涂敷专用设备,它可靠性、可控性、再现性、重复性、安全性、维修便捷性好,并开发出一套完整的涂敷工艺,经过反复验证,符合防渗碳范围的技术要求、重现性好。     

液相Al-Si共渗提高Ti3Al基合金高温抗氧化性

使用Al-8Si（mass %）合金熔体对Ti3Al基合金表面进行液相Al-Si共渗硅处理，在表层发生了不同程度的界面反应，经X射线能谱分析和对涂层的X射线衍射分析，推断涂层由TiAl3及Ti-Si化合物组成.经1 013 K/6 min+983 K/10 min的二次改性处理，可明显改善Ti3Al基合金的高温抗氧化性.1173 K/100 h氧化后的涂层组织，分析表明，涂层改善基体抗高温氧化性的根本原因是在最外层生成了一薄层致密的Al2O3膜.相关机理还有待更深一步研究.     

几种涂料的防渗碳试验及选择应用

在产品加工中,渗碳件有些部位不需要渗碳,而需要采用涂料法对其进行了防渗碳。本文通过几种防渗碳涂料的防渗碳试验,对比几种涂料的防渗碳保护效果,根据试验结果确定合适的涂料应用于轴承套圈生产中。     

EIS study of a self-repairing microarc oxidation coating

The self-repairing microarc oxidation (MAO) coating consisting of a bottom nanocrystalline layer covered by a top conversion ceramic coating was fabricated on 2024 Al alloy by a duplex process with surface mechanical attrition (SMAT) prior to microarc MAO treatment. A 20 μm thick nanocrystalline layer with average grain size of 52.8 nm was fabricated by SMAT, and on which covered by a top MAO coating of 5 μm. The self-repairing property caused by the formation of a dense passive film at the damaged regions contacting the bottom nanocrystalline layer enhances the corrosion reisitance of the SMAT-MAO coating.     

复合材料导电铝涂层的表面喷丸

在火焰喷涂过程中,金属Al的熔滴表面被氧化,在涂层中凝固时形成一层电绝缘的氧化物(Al2O3).同时涂层中的空隙都会影响Al涂层的导电性能.本文通过对涂层表面进行喷丸处理,从而细化熔滴颗粒,降低涂层孔隙率.提高涂层的导电性能.经过喷丸处理后的涂层,电阻可以减小至0.043mΩ,与未经过喷丸处理的涂层比较,电导率提高至1...     

Corrosion protection of AZ31 magnesium alloy by a TiO2 coating prepared by LPD method

TiO₂ layer was prepared as a protective coating for AZ31 magnesium alloy by the liquid phase deposition (LPD) method followed by an annealing treatment. The structural evolution and crystallization of coating brought by annealing were investigated by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD), respectively. The corrosion protection performance was evaluated in a three-electrode electrochemical examination system. The anatase TiO₂ layer shows evident corrosion resistance. With the increase of the annealing temperature and prolongation of annealing time, the anticorrosion property was improved. The improvements of the anticorrosion properties were related with the structural evolution of the coating brought by the annealing treatment.     

不锈钢表面含Cu功能梯度复合改性层的制备及抗菌性能

为提高奥氏体不锈钢(ASS)的耐磨性及赋予其抗菌性能,应用改进的活性屏离子渗氮(ASPN)技术,将纯铜冲孔板置于不锈钢冲孔板上面作为活性屏的顶盖,对316奥氏体不锈钢在低温下(430℃)进行表面渗氮处理,在其表面形成由含Cu抗菌沉积层和S相(氮在奥氏体中的过饱和固溶体γ_N)硬质支撑层组成的功能梯度复合改性层。用扫描电镜(SEM)及其所附能谱仪(EDS)、X射线衍射仪(XRD)表征复合改性层的组织形貌、成分及相结构。用显微硬度计和往复摩擦磨损试验机测试了基体和复合改性层的显微硬度和摩擦磨损性能,用金黄色葡萄球菌进行体外抗菌试验评价复合改性层的抗菌性能。结果表明,在偏压达到250 V后,形成了连续分布的硬质S相扩散层和含Cu沉积层组成的复合改性层。改性层表面最高硬度可达928 HV0.05,与Si₃N₄小球对磨时比磨损率较基体降低约57.76%,显著提高了不锈钢的耐磨性。抗菌试验表明,复合改性层与金黄色葡萄球菌接触24 h后,对金黄色葡萄球菌抗菌率提高到98.5%。改进的活性屏离子渗氮技术制备的功能梯度复合改性层可以有效提高...     

Manufacturing and Macroscopic Properties of Cold Sprayed Cu-In Coating Material for Sputtering Target

This study attempted to manufacture a Cu-In coating layer via the cold spray process and to investigate the applicability of the layer as a sputtering target material. In addition, changes made to the microstructure and properties of the layer due to annealing heat treatment were evaluated, compared, and analyzed. To examine the microstructural and property changes made to the Cu-In coating layer and Cu coating layer (comparison material), ICP, XRD, SEM, and other tests were conducted; purity, density, hardness, porosity, and bond-strength were measured. The results showed that coating layers with thickness of 20 mm (Cu) and 810 μm (Cu-In) could be manufactured via cold spraying under optimal process conditions. With the Cu-In coating layer, the pure Cu and intermetallic compounds of Cu₇In₃ and CuIn₄ were found to exist inside the layer regardless of annealing heat treatment. The preannealing inconsistent microstructure of the layer, whose phases were difficult to distinguish was found to have transformed into one with clearer phase distinction and fine, consistent grains following thermal treatment via a progress of recovery, recrystallization, and grain growth. The porosity and hardness values of the coating layers were 1.4% and 133.9 HV, respectively, for Cu and 3.54% and 476.6 HV, respectively, for Cu-In. The values of the Cu-In layer were higher than those of the Cu layer in terms of porosity and hardness, which declined drastically after annealing. With the porosity of the Cu-In coating layer in particular, the higher value found during the preannealing stage dropped to 0.36% after heat treatment of 773 K/1 h as the level on a par with pure Cu (0.44%), thus indicating the improved quality of the Cu-In layer. Moreover, the results of the bond-strength measurement performed on the Cu-In coating layer and annealing treated materials revealed the strength to be relatively high for heat treated coating layers. Based on the findings of this study and on the comparison and discussion of the properties that are typically required of the target material, the Cu-In coating layer manufactured via cold spray process and annealing heat treatment can be said to be applicable as sputtering target in the future.     

Microstructure and corrosion resistance of modified 2024 Al alloy using surface mechanical attrition treatment combined with microarc oxidation process

A top ceramic coating was fabricated on the surface mechanical attrition treatment (SMAT) modified nanocrystalline layer of 2024 Al alloy by microarc oxidation (MAO) process. The corrosion resistance of the SMAT-MAO composite coating was studied by EIS. The results show that SMAT-MAO composite coating with 10 μm top ceramic coating exhibited better corrosion resistance, while the SMAT-MAO coating with the thickness of 15 μm showed worse corrosion resistance compared with those simple MAO coatings with same thickness. The formation of a dense passive film at the damaged region caused by the bottom nanocrystalline interface contributed to the improved corrosion resistance property.     

玻璃涂层的制备与性能研究

用落球试验，扫描电镜，X射线衍射，电化学测试等方法对用热熔敷法和火焰喷熔法制取的玻璃涂层性能进行了研究，结果表明，两种方法得到的玻璃涂层表面质量好，主要由玻璃相组成，有少量晶相析出；火焰喷熔涂层与金属的作用剧烈，反应充分，形成的过渡层宽，密着强度较热熔敷涂层的高，且后者的底釉层与面釉层之间存在界面夹层，影响面釉层的密着；热熔敷涂层与基体反应轻微，耐蚀性好，而火焰喷涂层与基体反应剧烈，耐蚀性差。