631 results about "Crack free" patented technology

A method and apparatus for growing low defect, optically transparent, colorless, crack-free, substantially flat, single crystal Group III nitride epitaxial layers with a thickness of at least 10 microns is provided. These layers can be grown on large area substrates comprised of Si, SiC, sapphire, GaN, AlN, GaAs, AlGaN and others. In one aspect, the crack-free Group III nitride layers are grown using a modified HVPE technique. If desired, the shape and the stress of Group III nitride layers can be controlled, thus allowing concave, convex and flat layers to be controllably grown. After the growth of the Group III nitride layer is complete, the substrate can be removed and the freestanding Group III nitride layer used as a seed for the growth of a boule of Group III nitride material. The boule can be sliced into individual wafers for use in the fabrication of a variety of semiconductor structures (e.g., HEMTs, LEDs, etc.).

A surgical tool (5) used for preparing a surgical sinus-lift osteotomy has a defined thread geometry in series with an osteotome tip to cut, crack and push bone from the sinus floor upward into the sinus cavity in a tactual, gentle and controlled motion. The apical osteotome tip is driven into a pre-drilled pilot osteotomy after the cutting threads are engaged and rotated until the sinus floor is cracked free. Once the bony sinus floor is cracked free, a fluid passageway can be pressurized with a sterile fluid at a defined pressure to release and push the sinus membrane upward into the sinus cavity to create a desired apical cavity for grafting. The invention solves the problems for preparing a sinus-lift surgical osteotomy and desired cavity space while minimizing the risk of compromising or tearing the sinus membrane. The invention allows the physician to easily form the desired sinus cavity to allow for grafting and to receive a screw formed dental implant while minimizing the risk of certain undesired surgical conditions.

The invention belongs to the technical field of alloy material, and relates to an improvement on the prior art, in particular to special alloy powder for laser cladding of high-hardness crack-free iron-based alloy. The formula of the alloy powder comprises the following compositions in weight percentage: 0.3 to 0.5 of C, 1.2 to 2.0 of Si, 0.4 to 1.0 of B, 1.5 to 2.5 of Ni, 1.0 to 1.5 of Cr, 1.0 to 1.5 of Mn, 1.5 to 2.5 of Mo, 0.15 to 0.7 of V, and 0.15 to 0.7 of Nb, the balance being Fe; and the total weight of the compositions is 100 percent. The special alloy powder can obtain the iron-based alloy with large area, large thickness and no crakes for laser cladding without preheating and subsequent heat treatment, has high strength, hardness and wear resistance and good plastic toughness of a cladding layer, and has lower cost compared with most of hot spraying self melting alloy powder and the prior laser cladding special iron-based alloy powder.

The invention relates to a microbeam tungsten argon arc welding method for a magnesium alloy thin-walled tube. A low-magnesium aluminum alloy welding wire is used as a filling material, and the thin-walled tube is welded by a microbeam tungsten argon arc welding process under inert gas shielding. The low-magnesium aluminum alloy welding wire comprise 9.5%-11.6% of Al (aluminum), 0.6%-1.75% of Zn (zinc), 0.15%-0.35% of Mn (manganese), 0.01%-0.05% of Cu (copper), 0.02%-0.05% of Si (silicon) and the balance Mg (magnesium) in mass percent. The microbeam tungsten argon arc welding method for the magnesium alloy thin-walled tube is high in welding efficiency and convenient and flexible in application, and can be used for obtaining a crack-free welding joint without magnesium-aluminum brittle compounds. Compared with a conventional tungsten argon arc welding method, the microbeam tungsten argon arc welding method has the advantages that arc stability of microbeam argon arc welding for the magnesium alloy thin-walled tube is obviously improved, the tensile strength of the welding joint is 30% higher than that of a conventional tungsten argon arc welding joint, the elongation of the welding joint is increased by 10%, and the use requirements of industrial production on magnesium alloy thin-walled tube welding component can be met.

We have developed a scalable approach to directly incorporate grain-refining nanoparticles into conventional hot-tear-susceptible aluminum alloy powders. These aluminum alloy powders may be additively manufactured into high-strength, crack-free aluminum alloys with fine equiaxed microstructures by incorporating nanoparticle nucleants to control solidification during additive manufacturing. Some variations provide an additively manufactured aluminum alloy comprising aluminum, one or more strengthening elements, and at least one grain-refining element, wherein the additively manufactured aluminum alloy has a microstructure with equiaxed grains. Aluminum alloys with grain refiners are useful in many processes beyond additive manufacturing. Some variations provide an aluminum alloy comprising aluminum, copper, magnesium, at least one of zinc or silicon, and grain-refining nanoparticles selected from zirconium, tantalum, niobium, or titanium, wherein the aluminum alloy has a microstructure that is substantially crack-free with equiaxed grains.

The invention discloses a 900MPa high-strength steel preheating-free combined welding method. 700-800 MPa low-hydrogen type high-tenacity shielded metal arc welding is adopted for backing welding, then a 900MPa high-tenacity solid wire is matched with Ar+CO2 mixed gas shielded welding for implementing filling welding, and a 800MPa flux-cored wire is matched with CO2 gas shielded welding for cosmetic welding. A crack-free welding joint can be obtained by welding 900MPa high-strength steel through adopting a preheating-free and postweld heat treatment free combined welding process, and a joint region is smooth and clean, and can meet operating requirements on a high-strength steel welding structure for higher bearing capacity because the room temperature tensile strength of weld metal is more than 860MPa and the damping power of a V-shaped notch of the weld metal with the test temperature of 0 DEG C is more than 90J; and meanwhile, the method has welding cost reduced by about 25 percent, simple and convenient operation and easy popularization.

A method for formulating a CIGS nanoparticle-based ink, which can be processed to form a thin film with a crack-free limit (CFL) of 500 nm or greater, comprises: dissolving or dispersing Cu(In,Ga)S₂ and Cu(In,Ga)Se₂ nanoparticles; mixing the nanoparticle solutions/dispersions and adding oleic acid to form an ink; depositing the ink on a substrate; annealing to remove the organic components of the ink formulation; forming a film with a CFL ≧500 nm; and, repeating the deposition and annealing process to form a CIGS film having a thickness ≧1 μm. The film so produced may be incorporated into a thin film photovoltaic device.

An iron based hardfacing alloy with an undiluted (all weld material) alloy composition is substantially balanced in order to achieve an hypo-eutectic primary austenitic with secondary martensitic solidification mode. The alloy enables the deposition of substantially crack-free single layers of hardfacing onto industrial components without any post weld treatment. The hardfacing alloy is capable of withstanding abrasion of silicious earth particles when applied to industrial products, such as tool joints, stabilizers and casing and other tubulars used in oil and gas well drilling, and other industrial products.

The invention relates to a preparation method of a crack-free large-area optical crystal, in particular to a preparation method of a crack-free large-area opal structure and an inverse opal structural optical crystal. A support substrate of the optical crystal selected in the invention is a hydrophilic flexible substrate, and the crack-free large-area opal structure or a composite opal structural optical crystal can be obtained by performing self-assembly on monodispersed colloid particles on the support substrate or performing co-assembly and polymerization on the monodispersed colloid particles and a water-soluble polymer monomer on the hydrophilic flexible substrate. A crack-free large-area inverse opal structural optical crystal can be obtained by further dissolving the monodispersed colloid particles in the composite opal structural optical crystal. The preparation method related to the invention has the advantages of low cost, easiness for operating, environmental friendliness and high generality. The prepared optical crystal can be practically applied to the fields of high-performance optical devices, chemistry, biochemical detection, and the like.

A method for constructing a composite bridge superstructure of simple precast elements. According to the method, the bridge superstucture is comprised of one or more prestressed beams aligned substantially parallel to the bridge longitudinal axis. On top of the prestressed beams, there is placed a plurality of full width, precast deck slabs forming the bridge deck, with the precast deck slabs being transversely disposed side by side, with adjacent slabs attached by joints to complete the bridge deck structure. The deck slabs are spaced from the beams by spacing devices, such that a gap is left between the beams and the deck slabs and the bridge deck structure is prestressed separately from the beams. Subsequent to the prestressing of the deck structure and the beams, the bridge deck structure is connected to the beams by a concrete layer cast in situ in the gap between the bottom face of the precast deck slabs and the top face of the prestressed beams. The concrete is preferably of the low shrinkage type but normal shrinkage concrete may also be employed. The connection is further reinforced by a plurality of shear stirrups. The method is characterized by separate prestressing of the deck structure and the beams and by natural compression of the connecting concrete layer resulting in significant savings of construction time and costs. The construction sequence according to the method enables the deck structure as well as the cast in place concrete layer connecting the deck structure to the beams to undergo a natural compressing process due to time dependent creep and shrinkage contraction of the beams relative to the connecting layer and the deck structure, thereby eliminating the need to apply additional prestressing. In addition, the substantially separate longitudinal prestressing of the deck structure and the beams is highly effective, achieving considerable saving of prestressing steel. The natural compressing of the deck structure and the cast-in-place concrete layer result in crack-free condition and better riding quality of the deck, thereby eliminating the well known drawbacks of additional prestressing, and saving maintenance costs.

Disclosed is a hardfacing alloy deriving its usefulness from carbides and borides of molybdenum and niobium. The alloy does not rely on chromium as an alloying agent. The hardfacing alloy is capable of being applied to a number of industrial substrates in a crack-free manner, and once applied convert the substrate to a wear- and abrasion-resistant material having an extended service life, even when subjected to harsh wear conditions.

The invention discloses a method and a device for preparing a crack-free cladding layer through ultrasonic vibration-assisted laser cladding. Ultrasonic vibration aging is directly introduced into a molten pool micro-area, a direct cavitation effect, a mechanical effect and a heat effect of an ultrasonic wave are utilized for promoting the uniformity of a cladding layer stress field and the refining of grain tissues, and the generation of cracks is inhibited from the root; the ultrasonic wave can be directly acted on a molten pool, a promoting effect on temperature and stress distribution uniformity is higher than an overall vibration effect of a workpiece far away from the molten pool, and the three effects of the ultrasonic wave have a better stirring effect than that of an electromagnetic stirring elimination method, so that the new method has essential difference relative to previous methods, and has better superiority. By repeated experiments, an effect of refining the grain tissues can be achieved so as to prepare the crack-free cladding layer with a favorable surface appearance.

The invention relates to a method for preparation of a ceramic nanofiltration membrane by an improved sol-gel technique. The method includes: adding nano-particles with certain particle size into sol to prepare a film coating solution, conducting film coating on a porous supporting body by the prepared film coating solution, airing and drying a wet film, and then carrying out direct calcinations, thus obtaining the nanofiltration membrane. In the invention, the nano-particles with a size of 3-50nm are employed to modify the supporting body surface macropore defect, and also can achieve the purpose of toughening gel and increasing its strength, thus effectively avoiding the problem of film cracking during drying. On a sheet, single tube or multi-channel supporting body with a pore diameter of 50-200nm, the ceramic membrane that is intact, crack-free, defect-free and has a pore diameter of 1-10nm can be prepared. The ceramic nanofiltration membrane prepared by the method has the advantages of narrow pore diameter distribution, simple process and good repeatability, and is suitable for large scale ceramic nanofiltration membrane production.

A method of fabricating a polycrystalline CVD synthetic diamond material having an average thermal conductivity at room temperature through a thickness of the polycrystalline CVD synthetic diamond material of at least 2000 Wm⁻¹K⁻¹, the method comprising: loading a refractory metal substrate into a CVD reactor; locating a refractory metal guard ring around a peripheral region of the refractory metal substrate, the refractory metal guard ring defining a gap between an edge of the refractory metal substrate and the refractory metal guard ring having a width 1.5 mm to 5.0 mm; introducing microwaves into the CVD reactor at a power such that the power density in terms of power per unit area of the refractory metal substrate is in a range 2.5 to 4.5 W mm⁻²; introducing process gas into the CVD reactor wherein the process gas within the CVD reactor comprises a nitrogen concentration in a range 600 ppb to 1500 ppb calculated as molecular nitrogen N2, a carbon containing gas concentration in a range 0.5% to 3.0% by volume, and a hydrogen concentration in a range 92% to 98.5% by volume; controlling an average temperature of the refractory metal substrate to lie in a range 750° C. to 950° C. and to maintain a temperature difference between an edge and a centre point on the refractory metal substrate of no more than 80° C. growing polycrystalline CVD synthetic diamond material to a thickness of at least 1.3 mm on the refractory metal substrate; and cooling the polycrystalline CVD synthetic diamond material to yield a polycrystalline CVD synthetic diamond material having a thickness of at least 1.3 mm, an average thermal conductivity at room temperature through the thickness of the polycrystalline CVD synthetic diamond material of at least 2000 Wm⁻¹K⁻¹ over at least a central area of the polycrystalline CVD synthetic diamond material, wherein the central area is at least 70% of a total area of the polycrystalline CVD synthetic diamond material, a single substitutional nitrogen concentration no more than 0.80 ppm over at least the central area of the polycrystalline CVD synthetic diamond material, and wherein the polycrystalline CVD synthetic diamond material is substantially crack free over at least the central area thereof such that the central area has no cracks which intersect both external major faces of the polycrystalline CVD synthetic diamond material and extend greater than 2 mm in length.

The invention discloses a method for preparing a magnesium and aluminum dissimilar metal clad plate. The method comprises the following steps: the removing of oxidization films on the surfaces of a magnesium plate material and an aluminum plate material, the stacking of the magnesium plate material and the aluminum plate material together, the continuous firm welding of four sides by a pulsed tungsten argon arc welding method, the placement of a magnesium and aluminum superposition piece in a tank-type electric furnace after four-side welding, the pressing of the superposition piece, the heating of the magnesium and aluminum superposition piece at a temperature of between 460 and 520 DEG C, the implementation of diffusive connection and other steps. The method does not need to adopt vacuum heating equipment with high price, has low connection temperature, can obtain the magnesium-aluminum diffusive welding clad plate of a crack-free brittleness-free compound in a common tank-type electric heating furnace; and the shearing strength of a connecting interface is between 22 and 30 MPa (reaching 50 percent of the shearing strength of a mother aluminum material) and can meet the using requirement of the magnesium and aluminum dissimilar clad plate.

The invention relates to a method for determining and building bound water for a crack-pore (hole) type reservoir core. The method sequentially comprises the following steps of: (1) selecting a crack-free reservoir core; (2) preparing formation water and simulated oil; (3) cleaning and emptying the core, saturating the formation water, driving water by dry gas or the simulation oil until the water does not come out, and thus obtaining the saturation degree of the bound water of a basic rock; (4) perforating the core; (5) calculating the saturation degree of the bound water of the crack-pore (hole) type reservoir core; (6) putting the core into a clamp, and quantitatively saturating bound water for the core; (7) heating the clamp under negative pressure until the system temperature is 120 DEG C, so that the water becomes steam and uniformly distributed; and (8) opening an inlet of the clamp, injecting the simulated oil or the dry gas for displacement, recording a water drainage amount,and thus obtaining the actual saturation degree of the bound water of the core. According to the method, the principle is reliable, the operation is easy, and a reliable physical simulation basis is supplied to a seepage experiment of a crack-pore (hole) type reservoir.

Disclosed herein are iron-based alloys having a microstructure comprising a fine-grained ferritic matrix and having a 60+ Rockwell C surface, wherein the ferritic matrix comprises <10 μm carbide precipitates. Also disclosed are methods of welding comprising forming a crack free hardbanding weld overlay coating with such an iron-based alloy. Also disclosed are families of alloys capable of forming crack-free weld overlays after multiple welding passes.

A method for growing high quality, nonpolar Group III nitrides using lateral growth from Group III nitride nanowires. The method of nanowire-templated lateral epitaxial growth (NTLEG) employs crystallographically aligned, substantially vertical Group III nitride nanowire arrays grown by metal-catalyzed metal-organic chemical vapor deposition (MOCVD) as templates for the lateral growth and coalescence of virtually crack-free Group III nitride films. This method requires no patterning or separate nitride growth step.

The invention provides an efficient carbonization and crack-free treatment method of bamboo pipes. The method comprises the following process steps that 1, the fresh bamboo pipes are drilled; 2, the bamboo pipes are stacked and enter a high-pressure tank; 3, the round bamboo pipes are softened and carbonized at a high temperature in the high-pressure tank; and 4, the round bamboo pipes are dried. The fresh round bamboo pipes are placed into a high-temperature saturated steam tank with the temperature ranging from 140 DEG C to 190 DEG C, high-temperature steam is utilized for fast heating, softening points of lignin, cellulose and hemicellulose can be reached fast, meanwhile, the hemicellulose is hydrolyzed fast at such a high temperature and humidity, and therefore the purpose of efficient carbonizing within a short time is achieved. Water in the bamboo pipes is drained by means of dry hot steam, the bamboo pipes are dried and shrunk and cannot cause cracking, thus, fast carbonization treatment and softening treatment are achieved, and the crack-free carbonized round bamboo pipes manufactured through the method are better in size stability and suitable for manufacturing artware, furniture, bamboo buildings and outdoor landscape, and have anticorrosion and anti-moth performance. The better processing method is provided for the bamboo industry.

The invention concerns an electrolyte for electroless deposition of metal layers with internal compressive stresses containing a metal base salt, a reducing agent, a complexing agent, an accelerator and a stabilizer. In order to make available an electrolyte of the said kind, from which uniform pore-free and crack-free metal-phosphorus coatings can be deposited with constant layers properties and high phosphorus contents at an elevated deposition rate over a long period of time, it is proposed by means of the invention that the electrolyte contain as metal base salt a metal salt whose anions contain at least one carbon atom and that is present in a starting concentration from 0.01 to 0.3 mol/L. At least one salt consisting of metal acetate, metal formate, metal oxalate, metal propionate, metal citrate and metal ascorbate, especially preferably metal acetate, is used as the metal salt whose anion contains at least one carbon atom. In addition, a method that is especially suitable for the use of the said electrolyte is proposed, where this method advantageously has a closed material circulation. Through the use of the invention especially pore-free and crack-free metal coatings with constant layer properties are uniformly deposited over a long time of use of the bath of at least 14-22 MTO.