403results about How to "Increase the dislocation density" patented technology

A method for manufacturing a light-emitting diode, which includes the steps of: providing a substrate having a plurality of protruded portions on one main surface thereof wherein the protruded portion is made of a material different in type from that of the substrate and growing a first nitride-based III-V Group compound semiconductor layer on each recess portion of the substrate through a state of making a triangle in section wherein a bottom surface of the recess portion becomes a base of the triangle; laterally growing a second nitride-based III-V Group compound semiconductor layer on the substrate from the first nitride-based III-V Group compound semiconductor layer; and successively growing, on the second nitride-based III-V Group compound semiconductor layer, a third nitride-based III-V Group compound semiconductor layer of a first conduction type, an active layer, and a fourth nitride-based III-V compound semiconductor layer of a second conduction type.

A light-emitting diode which has a significantly high luminous efficiency and which can be manufactured at a reasonable cost by one epitaxial growth and a manufacturing method thereof are provided. The above method includes: preparing a substrate provided with convex portions on one major surface, the convex portions being formed from a dielectric substance which is different from the substrate and which has a refractive index of 1.7 to 2.2; growing a first nitride-based III-V compound semiconductor layer in a concave portion on the substrate; growing a second nitride-based III-V compound semiconductor layer on the substrate from the first nitride-based III-V compound semiconductor layer in a lateral direction; and growing, on the second nitride-based III-V compound semiconductor layer, a first conductive type third nitride-based III-V compound semiconductor layer, an active layer, and a second conductive type fourth nitride-based III-V compound semiconductor layer.

A method and a device for processing metal materials with cryogenic laser shock belong to the fields of laser processing and subzero treatment. The device comprises a cryogenic treatment cavity, a laser, a liquid nitrogen tank, a temperature sensor and the like. The method is used for strengthening the materials in an ultra-low temperature environment by adopting the laser shock processing technology, insulating the materials for a period after the strengthening process, and heating the materials to be as hot as the ambient temperature. In the ultra-low temperature environment, the metal materials shrink, and a large quantity of dislocation is generated in the materials; due to the instant impact effect of the laser shock processing technology, the high-density dislocation in the materials moves at a high speed, so as to induce high-density nano twin crystal, which ensures that the materials have superior tenacity as well as high intensity, and brittle failure of the metal materials in the low-temperature environment can be avoided effectively; and a large quantity of nano educt is dissolved out from the materials, and the conversion of residual austenite as well as the thinning of martensite and crystal can be promoted effectively, which remarkably improves the mechanical properties and the mechanical properties of the materials.

The invention belongs to the technical field of preparation of metal and alloy, and provides a preparation method for high-strength and high-toughness ultra-fine grain aluminium alloy. The preparation method comprises the steps that aluminium alloy is firstly cast to form a cast-state blank; then the cast-state blank is turned into an ECAP (Equal Channel Angular Pressing) blank, and then the ECAP blank is subjected to homogenization treatment and curing quenching treatment; and then the blank subjected to the curing quenching treatment is subjected to 1-8 passes of ECAP dynamic ageing treatment at temperatures ranging from the room temperature to 300 DEG C. According to the preparation method, through the ECAP dynamic ageing treatment at different temperatures, the grain size of the alloy is obviously refined; and the form and distribution of a nanometer ageing precipitated phase are more reasonable, so that the strength of the alloy is greatly improved, and meanwhile the alloy has excellent ductility and toughness.

The invention discloses an aluminum alloy workpiece additive manufacturing method implemented through friction stir welding. On the basis of an existing electric arc additive manufacturing aluminum alloy workpiece, the characteristic that aluminum alloy is soft in property is combined, after an aluminum alloy workpiece is manufactured from electric arc additives layer by layer, friction stir welding intensification treatment is conducted on each layer, and therefore, defects such as pass gaps, interlayer incomplete fusion, air holes and the like can be eliminated through friction stir weldingwhen each layer is manufactured. Compared with the pure electric arc additive manufacturing aluminum alloy workpiece, by means of the method, the structural state of the aluminum alloy workpiece obtained through additive manufacturing can be improved; the grains can be finer; second-phase grains are finer and are distributed more uniformly; and the dislocation density achieved in the aluminum alloy additive manufacturing workpiece is increased. Compared with existing friction stir welding intensification, grain refining and defect elimination are conducted on each layer of the workpiece so that the strength of the whole workpiece can be improved rather than only surface modification, namely surface intensification, is conducted.

A method of making a group III-V nitride-based semiconductor substrate has the steps of: providing a first crystal substrate; placing the first crystal substrate on a susceptor; holding down the first crystal substrate on the susceptor; and growing a first group III-V nitride-based semiconductor crystal on the first crystal substrate.

The low temperature quick aluminizing agent specially for petroleum pipe and casing consists of metal source, activator, catalyst and stuffing. The metal source consists of 150-mesh Al powder in 10-20 wt% of the aluminizing agent, 120-mesh Zn powder in 10-25 wt%, 150-mesh Zn-Fe alloy powder in 10-20 wt% and/or 150-mesh Fe-Al alloy powder in 10-15 wt%. The activator consists of ammonium chloride, aluminum chloride, sodium fluoride and/or potassium bifluoride. The catalyst consists of 100-mesh Mo powder in 0-3 wt% and La and Os 0-3 wt%, with La and Os in the weight ratio of 1 to 1. The stuffing is 100-mesh alumina powder. The aluminizing agent is applied at 380-500 deg.c to obtain aluminized layer.

The invention discloses a high-strength, high-conductivity and heat-resisting aluminum alloy bus and a production method thereof. The high-strength, high-conductivity and heat-resisting aluminum alloy bus comprises the following components in percentage by mass: 0.4-1.1 percent of magnesium (Mg), 0.3-0.9 percent of silicon (Si), 0.85-2.1 percent of copper (Cu), 0.03-0.3 percent of zirconium (Zr), 0.05-0.38 percent of rare earth (La), less than 0.4 percent of Ferrum (Fe), less than 0.01 percent of manganese (Mn) and the balance of aluminum (Al), wherein the ratio of Cu to Mg is 1.9-2.3. The production method comprises the steps of: uniformly annealing a cast ingot obtained through smelting and casting for 10-20h at a temperature of 470-550 DEG C, furnace-cooling; controlling the temperature of the cast ingot to be 480-540 DEG C for thermally deforming, wherein the final temperature of the thermal deformation is not less than 380 DEG C, the total deformation rate of the thermal deformation reaches 80-94 percent; then carrying out cold deformation on a thermally deformed blank at the total deformation rate of 80-90 percent; annealing the deformed product, wherein the annealing temperature is 330-350 DEG C, the insulation time is 2h; carrying out solution treatment for 1-3h at a temperature of 490-525 DEG C; and carrying out artificial ageing treatment for 24-36h at a temperature of 175-200 DEG C.

The invention discloses a high-strength corrosion-resistant aluminum alloy profile and a preparation method thereof. The aluminum alloy profile comprises an aluminum alloy base body and a ceramic coating. The aluminum alloy base body is prepared from Cu, Si, Fe, Cr, Mg, Mn, Zn, Ti, Li, Ni, Zr, Y, W, V and the balance Al. The ceramic coating is prepared from SiC, Cr2O3, NiO, Cr3C2, Al2O3 and Si3N4. According to the high-strength corrosion-resistant aluminum alloy profile, ceramic powder is arranged on the surface of the aluminum alloy base body through plasma cladding, and then laser remelting is conducted, so that the obtained aluminum alloy profile has good mechanical performance such as strength, hardness and impact toughness; and meanwhile, the high-strength corrosion-resistant aluminum alloy profile has the beneficial effects of being resistant to corrosion, good in abrasion resistance, long in service life and the like.

Affords a Group-III nitride crystal substrate that is of low dislocation density and is inexpensive to manufacture, a method of manufacturing such a substrate, and Group-III nitride semiconductor devices that incorporate the Group-III nitride crystal substrate. The Group-III nitride crystal substrate manufacturing method includes: a step of growing, by liquid-phase epitaxy, a first Group-III nitride crystal (2) onto a base substrate (1); and a step of growing, by vapor-phase epitaxy, a second Group-III nitride crystal (3) onto the first Group-III nitride crystal (2). The Group-III nitride crystal substrate, produced by such a manufacturing method, has a dislocation density of 1×10⁷ dislocations/cm².

The invention provides a preparation method of a high-toughness metal-based nanometer composite material and belongs to the technical field of composite materials. The preparation method provided by the invention comprises the following steps of: firstly, using an atmosphere heat treatment process, generating a layer of a nanometer ceramic thin film on the sheet-shaped metal powder through reaction in-situ; and then carrying out densifying treatment by using a powder metallurgical process, so as to obtain the large compact metal-based composite material. The metal-based composite material prepared by the invention has a metal/ceramic alternative laminated structure, wherein a ceramic layer can be used for effectively restraining the reply of a metal layer and the crystal grain growth, improving the high-position wrong storage capability, keeping a nanometer crystal matrix structure, and causing the rotation and inactivation of fissures, so as to realize mechanical properties matched with the high toughness. The preparation method provided by the invention is simple, convenient and practicable, can be used for realizing the macro-quantized preparation of the large-size composite material, and is good for prompting engineering applications of the metal-based nanometer composite material.

This invention discloses a method for using necking extension to get extension films of low dislocation density, which utilizes deposition, selective extension and thermal oxidation to prepare GeSi substrates of low dislocation density and channels of high migration rate and gets films of exremely low dislocation density on a silicon wafer meeting the requirement of MOS devices or luminescent devices.

The invention provides a method for preparing an LED (light emitting diode) and belongs to the field of preparation of a photoelectronic device. The method comprises the following steps of: forming a transition layer consisting of a carbon nano tube and InN or a high In component InGaN epitaxial layer material on a substrate; growing an LED epitaxial wafer on the transition layer; carrying out photoetching, etching, electrode deposition and packaging process on the LED epitaxial wafer to prepare the LED with a positively assembled structure; or transferring the substrate, carrying out laser stripping and separation on the substrate and then carrying out photoetching, etching, electrode deposition and packaging process to prepare the LED with a vertical structure. According to the method, the crystal quality can be improved, but also the stress regulation and control can be realized.

The invention discloses a treatment method for improving alloy material strength, toughness, and anti-fatigue life. The method comprises solid solution and aging treatments. The method also comprises cryogenic cooling, tempering, and laser impact treatments. The cryogenic cooling treatment comprises the steps that: from room temperature, the alloy is cooled to -196 DEG C with a cooling speed of 1-10 DEG C/min, and the temperature is maintained for 10-40h. According to the tempering treatment, the alloy is heated to 100-150 DEG C, and the temperature is maintained for 2-3h. Laser impact parameters comprise laser impact spot diameter of 1-10mm, pulse energy of 1-10J, laser wavelength of 900-1200nm, repetition rate of 0.1-1HZ, pulse width of 15-40ns, and output laser pulse energy fluctuation no higher than +/-5%. The alloy material is preferably aluminum, magnesium, and titanium alloy. With the method, alloy material tissue can be compact, residue stress is low, and refined grains exist. With the method, yield strength, tensile strength, impact toughness, and anti-fatigue life of the alloy material can be greatly and simultaneously improved.

The invention relates to a high-strength Cu-Ni-Si alloy and preparation method thereof. The alloy comprises 2.0-6.0% of Ni, 0.5-1.5% Si, 0.5-1.0% of Ti, 0.5-1.0% of Mn, 0.5-1.0% of Ag and the balance of copper and unavoidable impurity elements. The preparation method sequentially comprises the following steps of smelting; casting; homogenization treatment; hot rolling and solution treatment; pre-cold rolling and aging treatment; and cold-rolling deformation. A Ni2Si non-oxide reinforcing phase is generated in the alloy disclosed by the invention; after the rolling is carried out repeatedly, the nucleation positions of precipitated phases can be increased, the more the broken grains, the more grain boundaries, the more nucleation positions of the precipitated phases and the more the precipitated phases; and under the condition that aging treatment is carried out repeatedly, the more precipitated phases are precipitated and thus the comprehensive performance of the alloy is dramatically increased, the strength, the elongation property at a high temperature and the electric conductivity are improved and the bending workability of the alloy is also improved.

The invention relates to non-oriented electrical steel for a variable frequency motor and a production method thereof, aiming to overcome the defects of traditional non-oriented electrical steel which has high strength and poor toughness and can not meet the requirement of the variable frequency motor and complex process. The non-oriented electrical steel comprises the flowing chemical components in percentage by weight: 0.001-0.015 percent of C, 0.3-0.9 percent of Mn, 0.4-1.6 percent of Cr, 0.1-1.2 percent of Al, 0.9-1.6 percent of Si, no more than 0.08 percent of P, no more than 0.015 percent of S, no more than 0.008 percent of N and the balance of Fe and residue, wherein the sum of the weight percent of Si and Al is 1.4-2.2 percent, the sum of the weight percent of Cr and Mn is 0.7-2.5 percent, and Cr/Mn is 0.9-2.0. The production method comprises the following steps of: smelting by using a clean steel process and continuously casting to form a billet; heating the billet; roughly rolling; finish rolling, and controlling the accumulated percentage of reduction of former four passes to be 80-95 percent; reeling; naturally cooling to the room temperature; washing with acid; cold rolling; decarbonizing; soaking; cooling according to conventional method, coating and finishing. The invention has the advantages of simple process, low iron loss at low frequency and power frequency, lower iron loss at high frequency, higher magnetic induction as well as good corrosion resistance and stamping property.

The invention discloses a production method for manufacturing cold-rolled oriented silicon steel with high magnetic strength by using a generally oriented steel raw material. The method comprises the following steps: (1) smelting, carrying out vacuum treatment, refining and continuously casting into a billet; (2) carrying out hot rolling; (3) normalizing and pickling; (4) wherein the single cold rolling pressure ratio is greater than or equal to 82%; (5) decarburizing annealing temperature; (6) annealing at high temperature, setting low thermal insulation of two steps, and high thermal insulation of one step, wherein the nitriding amount of an N gas is greater than or equal to 16ppm; (7) stretching, leveling and annealing, namely, pickling, coating, annealing and leveling. Gauss texture and nucleation are formed by the big pressure rate by cold rolling one time or twice, inclusions with enough quantity are formed by nitriding at an earlier stage of high-temperature annealing, development, stabilization and perfection of gaussian grains are recrystallized for the second time by using the enhanced inhibiting effect. By adopting the process, the magnetic property and the orientation degree of the product are improved when the silicon steel is produced by using the generally oriented silicon steel material, so that the property of the oriented silicon steel is improved, and high grade of cold-rolled oriented silicon steel 27Q105 is produced.