295results about How to "Prevent surface oxidation" patented technology

The invention discloses a method for controlling pitting on the surface of a medium steel plate, which prevents the surface of the medium steel plate from generating the pitting by controlling the components of a billet and adopting different heating and descaling processes according to different components, wherein the billet comprises the following chemical components in percentage by mass: 0.08 to 0.20 percent of C, 0.13 to 0.20 percent of Si, 0.90 to 1.60 percent of Mn, less than or equal to 0.02 percent of P, less than or equal to 0.02 percent of S, 0 to 0.04 percent of Nb, 0 to 0.018 percent of Ti, 0.02 to 0.05 percent of Alt and the balance of Fe and impurities; for a steel type containing a microalloy, a method for reducing Si content, heating the steel at a high temperature, descaling at the high temperature and fast cooling the steel after rolling the steel is adopted; and for a steel type containing no microalloy, a method for reducing Si content, heating the steel at a low temperature, descaling at the low temperature and fast cooling the steel after rolling the steel is adopted. The method of the invention can substantially clear off primary scales on the surface of the medium steel plate, thereby greatly reducing the occurrence of the pitting on the surface of the medium steel plate, and reducing the energy consumption and production cost and improving the production efficiency and the economic benefit of enterprises while guaranteeing the properties of the steel plate. The method is suitable to be popularized on a national scale.

Disclosed is a metallic pigment which enables to provide a coating film with very brilliant appearance and excellent corrosion resistance at the same time. Also disclosed is a coating material containing such a metallic pigment. Specifically disclosed is a metallic pigment which is composed of aluminum particles as the base particles whose surfaces are covered with a coating-layer composed of one or more layers. The outermost layer of the coating-layer contains a polymer which is obtained by polymerizing a monomer having a basic group and at least one polymerizable double bond. The monomer may preferably contain nitrogen. The metallic pigment may preferably be provided with a surface modification layer. Also specifically disclosed is a coating material containing such a metallic pigment.

A method of reducing tin whisker formation by creating a tin deposit which is inherently less prone to tin whisker formation or growth facilitated by oxide presence or corrosion reactions on the tin deposit surface. This is obtained by one or more of: (i) the deposition of a fine-grained tin deposit having an average grain diameter in the range of 0.05 to 5 microns; (ii) a phosphorous compound in the solution that is used to electroplate the tin deposit so that that the deposit incorporates trace amounts of phosphorous which in turn reduces tin whisker formation by preventing surface oxides even when exposed to heat or humidity; or (iii) a phosphorous compound, mercaptan, or organic or organo-metallic compound in a solution that applies a protective coating to the surface of a previously electroplated tin deposit, wherein the protective coating acts to minimize or prevent oxide formation or corrosion of the tin deposit during exposure to heat or humidity. Such tin deposits containing 80% to 100% by weight of tin exhibit minimal to no tin whisker growth.

The present invention relates to a nano-silicon composite negative electrode material, including graphite matrix and nano-silicon material homogeneously deposited inside the graphite matrix, wherein the nano-silicon composite negative electrode material is prepared by using silicon source to chemical-vapor deposit nano-silicon particles inside hollowed graphite. The nano-silicon composite negative electrode material of the present invention has features of high specific capacity (higher than 1000 mAh/g), high initial charge-discharge efficiency (higher than 93%) and high conductivity. The preparation process of the present invention is easy to operate and control, and has low production cost and is suitable for industrial production.

This invention provides a new through weld method to carry out welding of a base metal made of aluminum or that of aluminum alloy using high energy beams wherein a shield gas ambience (an inert gas ambience) to cover a welding site in a submerged-scar is formed, even a shield gas ambience (an inert gas ambience) to cover a welding site irradiated by the high energy beams. Since the former shield gas ambience to cover the submerged-scar pushes the keyhole against the gravity and/or the gas pressure force of the latter shield gas supplied to the laser irradiation side, then the forming of hang down of beads and the resultant projection of the welding base metal are prevented.

The invention discloses a laminar composite, comprising a first wrought aluminum alloy, a non-continuum-reinforced aluminum-based composite layer and a second wrought aluminum alloy which contact with each other in sequence, wherein the non-continuum-reinforced aluminum-based composite layer is a coated middle layer. According to the preparation method, the three-layer laminar composite containing the non-continuum-reinforced aluminum-based composite layer is prepared through a combination of extrusion cladding and rolling, wherein the extrusion cladding refers to bidirectional side extrusion of the non-continuum-reinforced aluminum-based composite layer located at the middle by wrought aluminum alloy rods located at two sides. The laminar composite provided by the invention inherits the advantages of high specific strength, high specific rigidity and high modulus of a non-continuum-reinforced aluminum-based composite and the advantages of good fatigue resistance, fracture toughness and corrosion resistance of wrought aluminum alloy.

Provided is a method for manufacturing a high-strength galvanized steel sheet, made from a steel sheet containing Si and/or Mn, having excellent exfoliation resistance during heavy machining. When a steel sheet containing 0.01% to 0.18% C, 0.02% to 2.0% Si, 1.0% to 3.0% Mn, 0.001% to 1.0% Al, 0.005% to 0.060% P, and 0.01% or less S on a mass basis, the remainder being Fe and unavoidable impurities, is annealed and galvanized in a continuous galvanizing line, a temperature region with a furnace temperature of A° C. to B° C. (600≦A≦780 and 800≦B≦900) is performed at an atmosphere dew-point temperature of −5° C. or higher in a heating process.

The invention discloses a preparation method for a TiAl alloy bar and relates to a preparation method for a bar. The preparation method for the TiAl alloy bar aims at solving the problems that according to a TiAl alloy bar prepared through an existing method, the preparation process is complex, the surface of the bar cracks, the diameter is nonuniform, the bar structure grain size is nonuniform, and TiAl alloy reacts with package materials and is molten when the extrusion temperature is too high. The preparation method for the TiAl alloy bar comprises the specific steps that 1, all raw material components are weighed; 2, a cast ingot is prepared through water cooling copper crucible induction skull melting; 3, pretreatment is conducted on an extrusion blank; and 4, bar extrusion is conducted, and thus the TiAl alloy bar can be obtained. The surface of the TiAl alloy bar obtained through the preparation method is free of cracking, the diameter is uniform, the bar structure grain size is uniform, and the process is simple.

The invention relates to a coaxial powder feeding device for broadband laser cladding and a powder feeding method thereof. The device comprises a sleeve module; a light beam isolation cover, and an inner-layer air cover, an outer-layer air cover and a cooling water cover for coating the light beam isolation cover in sequence from inside to outside are arranged at the bottom end of the sleeve module; two powder feeding pipes symmetrically arranged about the light beam isolation cover are arranged between the inner-layer air cover and the outer-layer air cover at the bottom end of the sleeve module; outlets of the powder feeding pipes are rectangular pipes; outlets of the light beam isolation cover, the inner-layer air cover, the outer-layer air cover and the cooling water cover at the bottoms are rectangular; and the sleeve module is provided with a water injecting port, a water outlet, an outer-layer protective gas inlet, an inner-layer protective gas inlet and a powder feeding inlet. The method comprises three steps of connection of external source equipment, powder feeding device parameter adjustment and coaxial broadband powder feeding laser cladding. The device can prevent fused metal liquid from splashing to block the outlet of the powder feeding device, can enable the powder spot pavement to become more uniform in powder spot shaping, and is simple in structure and easy to machine.

A perpendicular magnetic recording medium is disclosed that includes a substrate; a soft magnetic underlayer formed on the substrate; a seed layer of an amorphous material formed on the soft magnetic underlayer; an oxidation prevention layer formed on the seed layer; an underlayer formed on the oxidation prevention layer, the underlayer including multiple crystal grains formed of Ru or a Ru alloy having an hcp crystal structure, and a first air gap part configured to separate the crystal grains from each other; and a recording layer formed on the underlayer, the recording layer including multiple magnetic particles having a magnetocrystalline easy axis in a direction substantially perpendicular to the surface of the substrate, and one of a second air gap part and a non-magnetic non-solid-solution phase, the one being configured to separate the magnetic particles from each other. The oxidation prevention layer includes a noble metal element other than R.

The invention discloses a method for preparing a TiAl alloy plate without canning in order to solve the problems that an existing ingot metallurgy canning and rolling the TiAl alloy plate is complicated in process, high in machining cost and low in raw material utilization rate, and a TiAl alloy bar prepared through a powder metallurgy method is easy to introduce impurities and is high in cost. The method comprises the specific steps of 1, weighing all raw material ingredients; 2, preparing a casting ingot through induction skull melting of a water-cooling copper crucible and melted model precision casting; 3, carrying out blank pre-treatment; 4, carrying out a first plate extrusion stage; 5, carrying out a second plate extrusion stage, thus obtaining the TiAl alloy plate. According to the method for preparing the TiAl alloy plate without canning, disclosed by the invention, the surface of the obtained plate is smooth and has no cracks, and the TiAl alloy plate is uniformly organized, is small in crystal grain and has excellent mechanical performance.

The semiconductor device is formed according to the following steps. A TiN film 71 and a W film 72 are deposited on a silicon oxide film 64 including the inside of a via-hole 66 by the CVD method and thereafter, the W film 72 and TiN film 71 on the silicon oxide film 64 are etched back to leave only the inside of the via-hole 66 and form a plug 73. Then, a TiN film 74, Al-alloy film 75, and Ti film 76 are deposited on the silicon oxide film 64 including the surface of the plug 73 by the sputtering method and thereafter, the Ti film 76, Al-alloy film 75, and TiN film 74 are patterned to form second-layer wirings 77 and 78.