添加MoS2和C对粉末冶金金刚石复合材料性能的影响

研究了ＭｏＳ２和Ｃ对金刚石复合材料性能的影响，实验结果表明，ＭｏＳ２和Ｃ的加入提高了金刚石复合材料的硬度和抗弯强度，改善了减摩性能，使金刚石复合材料的切割率、出刃高度和磨削比提高，磨损量下降，从而提高了工具的切削效率和使用寿命。     

La2O3对MnO2碳热还原的催化

研究了稀土氧化物Ｌａ２Ｏ３作为添加剂对ＭｎＯ２碳热还原的作用，通过不还原实验，发现Ｌａ２Ｏ３对ＭｎＯ２碳热还原具有催化作用，对还原后试样进行ＳＥＭ分析，认为其催化作用是通过催化试样中碳的气化反应面实现的。     

氧化锰在锰铁渣中的热力学活度及金属与渣相间锰的分布

研究了埋弧炉锰铁生产中由ＭｎＯ－ＣａＯ－ＭｇＯ－ＳｉＯ２－Ａｌ２Ｏ３组成的标准炉渣。渣中Ａｌ２Ｏ３含量固定在５％。本研究目标集中在１５００℃时锰铁渣中ＭｎＯ的热力学活度上。为了达到校准的目的，在１３００、１４００和１５００℃时重新测定了Ｍｎ在Ｐｔ－Ｍｎ合金中的热力学活度。在１５００℃ＣＯ气氛下研究了碳饱和的Ｍｎ－Ｓｉ－Ｆｅ－Ｃ合金与ＭｎＯ－ＣａＯ－ＭｇＯ－ＳｉＯ２－Ａｌ２Ｏ３渣之间的平衡。在试验中发现，ａＭｎＯ值随着ＭｎＯ的增加而增大，趋向于随ＣａＯ／ＭｇＯ比的增大而增大。ａＭｎＯ值也随着碱度的增大而增大。在渣－金属平衡试验中，金属相中碳和硅的含量为反比关系。当硅含量一定时，由于Ｍｎ／Ｆｅ比增加，碳在金相中的溶解度增加。金属中含硅量随着渣中ＳｉＯ２含量的增加而增加．以及当ＭｇＯ代替渣中的ＣａＯ时，金属中含硅量增加。增大渣碱度使金属相含硅量降低。     

铁碳金属颗粒与熔渣的反应

对ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３－ＦｅＯ熔渣体系与铁碳金属颗粒反应的脱碳反应速率及脱碳反应限度进行了研究。在实验条件下,脱碳反应速率随金属颗粒初始碳含量及熔渣中氧化亚铁含量的增加而增大。金属颗粒终点碳含量随熔渣中氧化亚铁含量的增加而降低,但反应最终远未达到平衡状态。当反应坩埚内壁衬有金属钼片时,金属颗粒的终点碳含量可以降到极低的水平。因而推断：在低碳含量范围内,熔渣中电子的传递能力对反应起着非常重要的作用     

高温条件下碳还原含SiO2熔渣的研究

研究了高温条件下用碳还原含ＳｉＯ２合成渣的过程。结果表明：温度是使氮化物（ＳｉＯ２,ＭｇＯ和Ａ１２Ｏ３）还原的重要因素,在较高的温度和碳过剩条件下,控制适当的熔渣碱度和增加ＭｇＯ含量,可增加渣中还原ＳｉＯ２所生成的ＳｉＣ并减少所形成的ＳｉＯ,实现在较高温度条件下抑制渣中ＳｉＯ２被还原的目的。     

碳KLL精细结构的研究

利用ＳＡＭ技术研究了金刚石、β碳化硅晶须和碳化钛粉末的碳ＫＬＬ精细结构。结果表明,由于碳原子的周围环境不同,含碳材料的表面和内部电子结构发生显著变化,相应的碳ＫＬＬ谱线的形状有差异,这些信息为开发新材料和改进工艺提供了重要的依据。     

SiC/MoSi_2复合粉末等离子体反应制备方法

在１９９８年５月法国尼斯召开的第１５届国际热喷涂会议上,来自法国国家生物材料研究所的Ｘ．Ｆａｎ等研究人员发表论文,介绍了一种用高温等离子反应制备ＳｉＣ－ＭｏＳｉ２复合粉末的新方法。研究者认为,采用添加ＳｉＣ对改善高温结构ＭｏＳｉ２材料的机械性能亦是最好的二相增强剂。ＭｏＳｉ２粉末以一种Ａｒ－Ｈ２－ＣＨ４感应等离子方法进行飞行碳化处理。使用能起粉末控制（运载）气体和“先躯物”作用的甲烷与ＭｏＳｉ２反应生成原位ＳｉＣ相。在研究实验条件下亦使大约８．０％的碳溶合到ＭｏＳｉ２粉粒中。用ＸＲＤ、ＳＥＭ和Ｅ…     

锰铁氮化

在一台高温天平装置上对固态锰铁进行了氮化处理。氮化速度及吸氮量与温度、金属成分和粒度有关，在完全转化的物料中得到的含氮量在２．７－９．２ｗｔ％之间。相分析表明，低碳锰铁生成的是硅氮化物ＭｎＳｉＮ２和碳氮化物（Ｍｎ，Ｆｅ）４（Ｃ，Ｎ）的混合物，其相对数量取决于物料的初始成分，高碳锰铁的分析表明，是氮置换了（Ｍｎ，Ｆｅ）碳化物晶格中的碳，氮化速度主要取决于温度和粒度。     

稀散金属近况（Ⅱ）

稀散金属近况（Ⅱ）周令治，邹家炎（广州有色金属研究院广州５１０６５１）２ＳＭ的重要用途２．１近年国外ＳＭ的应用结构多年来美与日是世界耗ＳＭ的大户，两匡应用ＳＭ的情况具有代表性。今将１９８５～１９９：年间国外ＳＭ的应用结构列入表８～１４。表８美与日的镓...     

35MnTiB推土机履带板用钢的研制

设计了一种履带板新钢种３５ＭｎＴｉＢ,该钢种同国内现有履带板用钢４０ＳｉＭｎ２相比,碳、锰含量降低。经过热处理后,可减少履带板在使用中的断裂现象,同时耐磨性不低于４０ＳｉＭｎ２履带钢,延长了履带板的使用寿命。     

碳含量对Cr25Ni20型奥氏体耐热钢高温氧化性能的影响

对两种不同碳含量的Cr25Ni20型奥氏体耐热不锈钢分别加热到800 和1 100 ℃循环氧化96 h后，进行了循环氧化分析，并利用扫描电镜观察钢材表面氧化膜形貌；利用X射线衍射仪对氧化膜进行物相分析；采用划痕法测量氧化膜与金属基体的黏附力。结果表明，氧化膜是由菱形结构的Cr2O3晶粒和尖晶石结构的MnCr2O4晶粒组成，随着氧化温度的升高，氧化物晶粒变得粗大并由菱形结构向尖晶石结构转变；碳含量的增加造成“贫铬”现象的发生，减缓保护性氧化膜的生成，降低氧化膜与金属基体的黏附力；随着氧化温度的升高，氧化膜横截面的厚度不断增加，氧化膜受破坏程度也不断加剧。     

Physicochemical interaction and structure development during the formation of metal gas-transport coatings on diamond (review) II. Mechanism

Formation of chromium, titanium, molybdenum, vanadium, and tungsten coatings on diamond under various metallizing conditions and with different phase compositions of the metal sprays is studied. In the initial stages this process is controlled by the interaction of the diamond (carbon) surface with metal oxides through the gas phase as well as by diffusion of the metal spray. After formation of a continuous layer further coating growth is controlled by carbon diffusion. A reduction in the rate of mass transfer to the reaction surface and the rate of carbon yield from it are factors which limit coating growth. The former is connected with depletion of the metal spray; with a decrease in volatile phase flow, and reduction of MoO₃, V₂O₅, and WO₃, as well as with their removal during pumping; a reduction of the dissociation and disproportioning rate of the oxides; retardation of metal ion diffusion in the metal spray and appearance of oxides (V₂O₃, VO, Ti₂O₃, TiO, etc.) in it which interact weakly with carbon. Emergence of carbon at the surface is specified by its inhibition under diffusion in the growing layer of the coating, filling of carbon vacancies in carbide (TiC, VC) lattices, carbidization of metal, and transformation of lower carbides into higher forms.Translated from Poroshkovaya Metallurgiya, No. 8 (356), pp. 57–63, August, 1992.     

大面积CVD金刚石膜的热铁板抛光

研制成功国内第1台大面积CVD金刚石膜热铁板抛光机.它可以在10^-3Pa真空条件下,加热到1 100℃;抛光台可以在0~10 r/min间实现无级调速,一次完成3片φ110 mm的金刚石膜的抛光.金刚石膜在980℃,2 h抛光的结果表明该装置有良好的抛光效果.金刚石膜在980℃抛光不同时间的Raman谱表明,金刚石热铁板抛光是金刚石石墨化和C原子不断扩散的过程.     

粉末扩散法金刚石表面金属化

研究粉末扩散法使金刚石表面金属化的工艺。采用铜(或钴)、碳化物形成元素铬(或钛)和金刚石混合粉在真空下进行扩散热处理,金刚石表面形成由碳化物层和合金层组成的涂层。涂层可以通过固相扩散反应和液相存在下的扩散反应两种模式形成。铜基和钴基胎体材料和涂层金刚石间具有良好的结合强度。同无涂层金刚石比较,含涂层金刚石胎体材料的抗弯强度提高9%~20%。     

Formation of chromium coatings alloyed with nickel on diamond

The methods of x-ray phase analysis are used to study the composition of chromium — nickel coatings and metallizing mixtures (metal spraying compositions) as a function of the annealing conditions. The thickness of the coatings is calculated from the weight gain by diamond. It is shown that coatings are formed mainly by the transfer of chromium and nickel through the gas phase to the reaction surface (diamond or the outer surface of the coatings) and diffusion of carbon from the diamond (into the coating) which determines the phase composition of the coating: Cr₃C₂, Cr, Cr₇C₃, and Ni. Nickel appears in the metal spraying compositions because of the reduction of NiO by the carbon of chromium and carbon monoxide. The formation of the phases in the metal spraying compositions, which block the intensity of evaporation of chromium (due to NiO restoration with chromium) and of Ni(Cr) (due to the dissolution of chromium in nickel), is the factor that limits the growth of the coating. This is the main reason for the decrease in the thickness of the coating when nickel monoxide is added to the chromium metallizing mixture.Institute of Materials Science Problems, Ukrainian Academy of Sciences, Kiev. Translated from Poroshkovaya Metallurgiya, No. 1 (361), pp. 47–51, January, 1993.     

Surface graphitization analysis of cerium-polished HFCVD diamond films with micro-raman spectra

The etching technique using Ce is a convenient and fast method for polishing and shaping diamond films. In this study, the influence of polishing parameters such as polishing temperature and time on the surface crystallinity and phase composition of diamond films was thoroughly investigated via the analysis of Raman spectra such as FWHM and ID/IG. Moreover, the issue on the graphitization of diamond after polishing with Ce was further researched through the detailed study of the depth distribution of Raman data including FWHM and ID/IG, and a result completely different from the hot-iron metal polished ones was obtained. The results showed that polished diamond films had considerably higher diamond content than those before polishing, and not a bit of graphitization was found in the polished ones, owing to a higher solubility of carbon in rare earth metal Ce than that in transition metals, and the original crystallinity of the films polished with Ce did not deteriorate.     

人造金刚石合成的亚稳定间隙固溶体机制

采用实验设计,获取了单一的金属薄膜;通过金属薄膜处的成分分析,发现了金刚石合成过程中触媒材料的成分变化和物质迁移,在比较现有金刚石合成理论的基础上,提出了人造金刚石合成的亚稳定间隙固溶体机制。     

Microstructural evolution of diamond growth during HFCVD

High resolution transmission electron microscopy (HRTEM) was used to study nucleation and growth mechanism of diamond by hot filament chemical vapor deposition (HFCVD) process. A novel technique has shown a direct evidence for the formation of the diamond-like carbon layer 8–14 nm thick in which small diamond micro-crystallites were embedded. These diamond micro-crystallites were formed as a result of transformation of diamond-like carbon into diamond. The diamond micro-crystallites present in the amorphous diamond-like carbon layer provided nucleation sites for diamond growth. Large diamond crystallites were observed to grow from these micro-crystallites. The mechanism of diamond growth will be presented based on experimental findings.     

金刚石表面的金属化

用真空蒸镀法在金刚石表面镀覆Ti层,并经扩散处理使金刚石表面形成TiC膜,实现了金刚石表面的金属化.X射线衍射分析证实了TiC的存在,利用XPS定量分析验证了在金刚石表面碳原子与钛镀层之间的反应扩散模型.经表面金属化的金刚石烧结体的力学性能测试表明,金刚石与粉末合金界面上的结合得到增强     

碳纤维表面沉积碳化钨膜研究

通过W(CO)6化学气相沉积(MOCVD)工艺,在碳纤维表面沉积得到了碳化钨膜材料,研究了碳纤维表面沉积碳化钨膜的工艺条件.结果表明:在400℃沉积温度下沉积时间15min,一定浓度的W(CO)6可解离沉积在碳纤维表面形成致密碳化钨膜;膜层厚度0.4μm,物相为WC1-x相,与碳纤维基体结合强度高.DTA分析表明,复合...