摘要:
A hard drive disk substrate is formed of a multi-phase ceramic-based material having at least two phases with amorphous phases being present in an amount less than about 1 volume percent based on the volume of the ceramic-based material or at least one phase being free metal. A process for producing the ceramic-based disk substrate is produced by forming a flat disk of a porous ceramic and then infiltrating the porous ceramic with a metal whereby a multi-phase ceramic-based computer hard drive disk is produced. Additionally, a step of passivating the porous ceramic by elevating it to a temperature of about 1300.degree. to about 1800.degree. C. before the infiltrating step may be performed, such that the surfaces are passivated and the reaction kinetics can be controlled during the infiltrating step. A preferred composite material is made of a multi-phase boron carbide composite material including grains having peaks with an average roughness value, Ra, of between about 1 to about 200.ANG., the roughness value being formed in situ by causing a micro hardness gradient of between about 19 and about 3200 Kg/mm.sup.2 in the various phases of the multi-phase boron carbide composite material.
摘要翻译:硬盘驱动器盘基板由具有至少两相的多相陶瓷基材料形成,其中无定形相以基于陶瓷基材料的体积或至少一相的量存在的量小于约1体积% 是免费金属。 通过形成多孔陶瓷的平板,然后用金属渗透多孔陶瓷来制造陶瓷基盘基板的方法,由此制造多相陶瓷基计算机硬盘驱动盘。 此外,可以在渗透步骤之前将其升高至约1300℃至约1800℃的温度来钝化多孔陶瓷的步骤,使得表面被钝化,并且可以在渗透步骤期间控制反应动力学 。 优选的复合材料由多相碳化硼复合材料制成,其包括具有平均粗糙度值Ra的峰值在约1至约200之间的晶粒,该粗糙度值通过使原位形成的微观硬度梯度 在多相碳化硼复合材料的各个相中约19至约3200Kg / mm 2。
摘要:
A hard drive disk substrate is formed of a multi-phase ceramic-based material having at least two phases with amorphous phases being present in an amount less than about 1 volume percent based on the volume of the ceramic-based material or at least one phase being free metal. A process for producing the ceramic-based disk substrate is produced by forming a flat disk of a porous ceramic and then infiltrating the porous ceramic with a metal whereby a multi-phase ceramic-based computer hard drive disk is produced. Additionally, a step of passivating the porous ceramic by elevating it to a temperature of about 1300.degree. to about 1800.degree. C. before the infiltrating step may be performed, such that the surfaces are passivated and the reaction kinetics can be controlled during the infiltrating step. A preferred composite material is made of a multi-phase boron carbide composite material including grains having peaks with an average roughness value, Ra, of between about 1 to about 200 .ANG., the roughness value being formed in situ by causing a micro hardness gradient of between about 19 and about 3200 Kg/mm.sup.2 in the various phases of the multi-phase boron carbide composite material.
摘要翻译:硬盘驱动器盘基板由具有至少两相的多相陶瓷基材料形成,其中无定形相以基于陶瓷基材料的体积或至少一相的量存在的量小于约1体积% 是免费金属。 通过形成多孔陶瓷的平板,然后用金属渗透多孔陶瓷来制造陶瓷基盘基板的方法,由此制造多相陶瓷基计算机硬盘驱动盘。 此外,可以在渗透步骤之前将其升高至约1300℃至约1800℃的温度来钝化多孔陶瓷的步骤,使得表面被钝化,并且可以在渗透步骤期间控制反应动力学 。 优选的复合材料由多相碳化硼复合材料制成,其包括具有平均粗糙度值Ra的峰值在约1至约200之间的晶粒,该粗糙度值通过使原位形成的微观硬度梯度 在多相碳化硼复合材料的各个相中约19至约3200Kg / mm 2。
摘要:
A lubricant comprising a mixture of a perfluoropolyalkyl ether and a phosphazene is described. The lubricant is useful in thin-film magnetic recording disk applications, where very low static and dynamical coefficients of friction are desired and balling effects are minimized.
摘要:
The invention is a complex-shaped article, comprising an article prepared by joining at least one multi-phase ceramic-metal part and at least one shaped part of another material, wherein the theoretical density of the at least one ceramic-metal part is greater than 80 percent.In another aspect, the invention is a process for preparing complex-shaped articles, comprising:(a) forming at least one ceramic-metal part;(b) forming at least one shaped part of another material; and(c) joining the at least one shaped ceramic-metal part with the at least one shaped part of another material such that a complex-shaped article is formed.The invention is a less costly and time-consuming process for preparing complex-shaped composite articles wherein the articles are formed of two or more selected materials wherein one of the materials is a ceramic-metal composite.
摘要:
Substantially pure 2,3,5,6-tetrachloropyridine is recovered from a mixture of chlorinated pyridines containing initially 2,3,5,6-tetrachloropyridine and other chlorinated pyridines in an improved process which comprises (a) reacting by contacting a first mixture of chlorinated pyridines with chlorine in the presence of a strong Lewis acid catalyst to thereby obtain a second mixture consisting essentially of 2,3,5,6-tetrachloropyridine and pentachloropyridine, and (b) recovering the 2,3,5,6-tetrachloropyridine from said second mixture. The reaction is normally conducted at a temperature of from about 150.degree. C. to about 300.degree. C. by pressurizing chlorine into a molten mixture of the chlorinated pyridines and maintaining such conditions until substantially all of the isomers have been converted to the symmetrical tetrachloropyridine or pentachloropyridine.
摘要:
The present invention is a laminate which comprises: a) a plastic substrate having a surface; b) an adhesion promoter layer which is a first plasma polymerized organosilicon compound deposited on the surface of the substrate in the substantial absence of oxygen; and c) a protective coating layer which is a second plasma polymerized organosilicon compound deposited on the surface of the adhesion layer at a power density from about 10.sup.6 J/kg to about 10.sup.8 J/kg, and in the presence of a sufficient stoichiometric excess of oxygen to form a silicon polymer of SiO.sub.1.8-2.4 C.sub.0.3-1.0 and H.sub.0.7-4.0. The coating layer provides abrasion and solvent resistance for the substrate, and the adhesion promoter prevents the coating layer from peeling off the substrate. The coated plastic substrate can be used in liquid crystal display devices as an alternative to glass.
摘要:
Improved polymeric optical fibers comprising a core of a copolymer prepared by anionic polymerization of alpha-methylstyrene and a monovinylidene aromatic comonomer at a temperature above 61.degree. C. and a cladding polymer are disclosed. The fibers have superior combination of high heat resistance, high flexibility, and low transmission loss in bent form.
摘要:
A method for preparing halogenated alkanes and alkenes which comprises reacting by contacting, for 0.005 to 0.1 second at a temperature of 675.degree. C. to 850.degree. C., a halogenating agent of the formula CCl.sub.x Br.sub.4-x, wherein x is an integer from 0 to 4, with a compound of the formula R.sub.2 CH.sub.2, wherein each R is H, Cl or Br, with or without the presence of inert gases. The utilization of the above conditions prevents the formation of large amounts of undesirable tars.
摘要:
A laminate has at least two layers, at least one of which comprises a polymer having more than one perfluorocyclobutane group. Such polymers impart qualities of environmental or protection, chemical and solvent resistance, hydrolytic stability, lubricity, low dielectric, hydrostatic stability, weatherability, flame resistance, chemical resistance, hydrolytic stability, lubricity, environmental protection, scratch resistance, solvent resistance, surface passivation, water repellancy, lower surface refractive index, lower surface coefficient of friction, fluid barrier properties, oil repellancy, thermal stability, and/or reduced moisture pick-up. Additionally, the coatings are optically clear, easy to apply either neat, in a solvent or otherwise, have relatively low cure temperatures for their temperature resistance, and exhibit insulating and planarizing capabilities.
摘要:
Highly chlorinated pyridines are prepared by reacting 2,6-dichloropyridine with chlorine at temperatures of from about 150.degree. to about 300.degree. C. in the presence of an aluminum, iron or silica oxide catalyst and under sufficient pressure to maintain the 2,6-dichloropyridine reactant as a liquid.