99results about How to "Lower yield stress" patented technology

A solder joint comprising a solder capture pad on a substrate having a circuit; and a lead free solder selected from the group comprising Sn—Ag—Cu solder and Sn—Ag solder adhered to the solder capture pad; the solder selected from the group comprising between 0.1 to 2.0% by weight Sb or Bi, and 0.5 to 3.0% Ag. Formation of voids at an interface between the solder and the solder capture pad is suppressed, by including Zn. Interlayer dielectric delamination is suppressed, and electromigration characteristics are greatly improved. Methods for forming solder joints using the solders.

The invention relates to a viscosity reducible radiation curable composition comprising at least one radiation curable component and a filler, wherein the composition has the properties i) a yield stress value of <1100 Pa, ii) a viscosity (at a shear rate of 1 sec⁻¹) between 1 and 1500 Pa·sec, and iii) a filler settling speed less than 0.3 mm/day.

Provided are a steel pipe for a linepipe having a heavy wall thickness and excellent fracture toughness in a base material, and methods of producing the same. A welded heat affected zone is achieved by suppressing lowering of yield stress caused by a Bauschinger effect by optimizing the metal microstructure of a steel plate. A steel pipe has a composition which contains by mass % 0.03 to 0.08% C, 0.10% or less Si, 1.00 to 2.00% Mn, 0.010% or less P, 0.0030% or less S, 0.06% or less Al, 0.005 to 0.020% Nb, 0.005 to 0.025% Ti, 0.0010 to 0.0060% N, and Fe and unavoidable impurities as a balance. Ti(%)/N(%) is a value which falls within a range of 2 to 4, and a Ceq value is 0.30 or more.

The invention discloses a method for preparing foamed magnesium used as a buffering energy absorption material. According to the method, the powder metallurgy pore-forming agent technology is adopted, urea and magnesium powder are used for preparing the foamed magnesium through the compounding and mixing step, the compression molding step and the sintering step, the urea is used as a pore-forming agent, and absolute ethyl alcohol is used as a binder; as a result, the pore structure of the material is more uniform, the performance of the obtained foamed magnesium material is improved, substances which pollute the environment cannot be produced after the urea and the absolute ethyl alcohol are removed at a high temperature, and the material cost is low; moreover, the two-section type sintering process is adopted, so that consumption of energy is reduced, preparation cost is lowered, and benefit is increased. The foamed magnesium prepared through the method has low yield stress and a wide stress platform, meets the requirement for a good buffering energy absorption material, can be well applied to a vehicle damper and the like to serve as the buffering energy absorption material, provides a novel technological approach for preparation of a material of a high-performance buffer and has very good application prospect.

The invention relates to a method for modifying nanofibrillar cellulose composition, comprising—preparing fibrous dispersion of ionically charged nanofibrillar cellulose (NFC), and—applying heat treatment at a temperature of at least 90° C. to the fibrous dispersion until the viscosity of NFC starts to decrease. The viscosity of the heat-treated NFC is reversible by applying shear forces to the NFC.

A high-strength cold-rolled steel sheet providing a product with a good surface condition after press forming, having excellent bake hardenability and anti room temperature aging property, and having a dual phase structure with a tensile strength of at least 340 MPa is provided.

A high-strength cold-rolled steel sheet has a structure comprising a main phase which is a ferrite and a secondary phase which is a low temperature transformation product including a martensite and has a hardness distribution of the ferrite phase in an arbitrary cross section having a length of 10 mm in the widthwise direction of the sheet which satisfies the relationship prescribed by (Hv_(max)−Hv_(ave))<0.5×(Hv_(ave). Hv_(max) is the maximum Vickers hardness of ferrite grains in a region at a distance of from (⅛)t to (¼)t in the thickness direction from the surface when the thickness of the high-strength cold-rolled steel sheet is t, and Hv_(ave) is the average Vickers hardness of ferrite grains in this region.

The invention discloses an ultrasonic wave vibration equal channel angular extrusion combined mold. An ultrasonic wave vibration system is fixed on a mold base in the vertical direction; an L-shaped concave mold hole is formed in the output end of the ultrasonic wave vibration system; the feeding direction of the concave mold hole is parallel to the ultrasonic wave vibration direction; the discharge direction of the concave mold hole is perpendicular to the ultrasonic wave vibration direction; guide columns are uniformly arranged on the mold base; guide sleeves which relatively move in match with the guide columns are arranged on the guide columns; the guide sleeves are fixed on a top base of the mold; a convex mold is also fixed on the top base of the mold; a plurality of material guide sleeve support rods are uniformly fixed on the mold base; material guide sleeve fixing plates are fixed on the tops of the material guide sleeve support rods; material guide sleeves in match with the convex mold are fixed on the material guide fixing plates; the material guide sleeves are positioned above the convex mold hole; gaps are formed between the material guide sleeves and the concave mold hole. The ultrasonic wave vibration system and an equal channel angular extrusion mold are reasonably combined to form the ultrasonic wave vibration equal channel angular extrusion combined mold, so that both the yield stress and the flowing stress of a material are reduced, and crystal grains of the material are refined, and the comprehensive mechanical property of the material is improved.

The invention relates to a method for forging a workblank of a transmission disc of a locomotive. A selected raw material is cut into a blank according to weight; the blank is placed into a heating furnace to be heated to 1100 DEG C to 1180 DEG C; the heated blank is placed into a lower mold cavity of a pre-forging lower die to be positioned, the blank is forged to enable a material of the blank to flow in a pre-forging mold cavity of a pre-forging upper die and the pre-forging mold cavity of the pre-forging lower die in the free upsetting radial direction, and a molded pre-forging piece forms a corresponding thinning part at a protrusion bridge part and correspondingly forms a thickening part at the position of a cavity; the pre-forging piece is turned over to be placed into the mold cavity of the pre-forging lower die to be automatically positioned, the pre-forging piece is forged to enable the material of the pre-forging piece to flow in finish-forging mold cavities of a finish-forging upper die and a finish-forging lower die in the radial direction, and a molded finish-forging piece outwards extends along a disc body to form three uniformly-distributed lug parts and a shaft sleeve located at the middle portion of the disc body; and parting-line flashes of the finish-forging piece are cut off, connecting skin is punched away, and the workblank of the forging piece is prepared. By means of the method, the manufacturing cost is reduced, the production efficiency is improved, the complete streamline of a material of the transmission disc product of the locomotive can be kept, and the transmission disc of the locomotive has the excellent overall performance.

The invention relates to ultra-high-performance anti-impact anti-abrasion concrete. Cement, microbeads and silica fume are used as cementing materials; aggregate and ultrafine aggregate are added to perfect the grain composition; nanometer ultrafine silicon dioxide, fibers, a water reducing agent, a defoaming agent, a regulating agent, a coagulation accelerator and a retarder are added to be usedas functional auxiliary agents. The concrete can be used for building or repairing parts with impact abrasion damage in hydraulic structures, can also be used for engineering parts with structure impact damage needing to be repaired, and has good construction performance, mechanical performance and impact abrasion resistance.

A solder joint comprising a solder capture pad on a substrate having a circuit; and a lead free solder selected from the group comprising Sn—Ag—Cu solder and Sn—Ag solder adhered to the solder capture pad; the solder selected from the group comprising between 0.1 to 2.0% by weight Sb or Bi, and 0.5 to 3.0% Ag. Formation of voids at an interface between the solder and the solder capture pad is suppressed, by including Zn. Interlayer dielectric delamination is suppressed, and electromigration characteristics are greatly improved. Methods for forming solder joints using the solders.

The invention discloses child toothpaste composition. The child toothpaste composition comprises, by weight, 0.1-5 percent of thickener, 0.5-4 percent of solubilizer, 1-60 percent of humectant, 10-90 percent of water, 0.1-2 percent of essence and the balance other components. Abrasives are not added into the child toothpaste composition, and toothpaste body is transparent, generates a little or nearly no foam, is easy to extrude and brush, so that friction to the surfaces of teeth is reduced. The child toothpaste composition is high in safety with the pH range being 5.5-7.5, and can be used as training toothpaste for children at the age of 2-6.

The invention discloses a stirring head power supply-assisted composite double-shaft friction stir welding method. The method comprises the steps that stirring friction heads are adopted as electrodes of a resistor heat source, high-density currents are provided for the interior of a to-be-welded workpiece through a direct-current switch power supply, and the resistor-assisted heat source is provided for the stirring heads rotating at a high speed in the friction stir welding process; the stirring heads rotating at the high speed are inserted into the two sides of a joint, and upsetting pressure is exerted to metal at the joint through a shaft shoulder, so that the metal material at the joint is softened; the metal structure at the joint achieves a plasticizing state under the stirring effect through the stirring heads, and meanwhile micro-forging treatment is conducted on the plasticized metal by adopting an ultrasonic vibration exciter, so that metal structure crystalline grains at the joint are refined; the stirring heads do forward feeding motion in the direction of the joint, a cavity formed after a stirring needle moves is continuously filled with the plasticized metal under the stirring and extruding effect of the stirring heads, and the plasticized metal is gradually cooled and solidified to form a welding joint. According to the method, wear of the stirring heads is reduced, the welding thickness is increased, the welding speed is increased, and welding defects are reduced.

A process for improving the rheological properties of an aqueous dispersion comprising adding a rheology modifier to the aqueous dispersion, and then adding a water soluble synthetic polymer flocculant to the aqueous dispersion. The rheology modifier may be selected from the group consisting of natural polymers, semi-natural polymers, synthetic materials and combinations thereof. The water soluble synthetic polymer flocculant may be selected from the group consisting of water soluble anionic polymers, cationic polymers, amphoteric polymers, nonionic polymers, and combinations thereof.

The disclosure provides for wrought products made of Al—Cu—Mg aluminum alloy composed as follows, as a percentage by weight, Cu_corr: 2.6-3.7; Mg_corr: 1.5-2.6, Mn: 0.2-0.5; Zr: ≦0.16; Ti: 0.01-0.15; Cr≦0.25; Si≦0.2; Fe≦0.2; other elements <0.05 the rest aluminum; with Cu_corr>−0.9 (Mg_corr)+4.3 and Cu_corr<−0.9 (Mg_corr)+5.0; where Cu_corr═Cu−0.74 (Mn−0.2)−2.28 Fe and Mg_corr═Mg 1.73 (Si−0.05) for Si≧0.05 and Mg_corr═Mg for Si<0.05 and their manufacturing process.

The invention discloses a heat source auxiliary compound double-axis needleless dynamic friction stir welding method. Positive and negative electrode dynamic clamping heads and a guide pretightening wheel are adopted to finish clamping of workpieces to be welded; a direct-current switch power supply is used for providing high-density current into the workpieces to be welded; metals in joints of the workpieces to be welded are preheated; stirring heads rotating at high speed are pressed in two sides of the joints; positive pressure is applied to the metals in the joints through shaft shoulders, so that the metal materials in the joints are softened; the stirring heads rotating at high speed enable the metal structures in the joints to achieve a plastified state under the friction stirring effect; meanwhile, a ultrasonic exciter is adopted to finely forge the plastified metals; the workpieces to be welded are forwards fed along with a welding worktable in the directions of the joints; and the plastified metals are continuously filled in a cavity formed after movement of the stirring head under the stirring and extruding effects of the stirring heads, and are gradually cooled to condense as final welding lines. The method relieves the wear of the stirring heads, increases the welding thickness, accelerates the welding speed, and reduces the welding defects.

The invention discloses underwater dispersion-resistant porous concrete with a large particle size. The underwater dispersion-resistant porous concrete comprises the following raw materials: aggregate, cement, mineral admixture, water and a thickener, wherein a mass ratio of the sum of the cement and the mineral admixture to the aggregate is 0.19-0.23; the mineral admixture is micron silicon powder and nano calcium carbonate, wherein the micron silicon powder accounts for 0%-10% of the cement, and the nano calcium carbonate accounts for 0%-1% of the cement; the thickener accounts for 2%-4.5% of the sum of the cement and the mineral admixture; the aggregate is graded aggregate with the particle size of 5mm-20mm; and water accounts for 0.25-0.35 of the sum of the cement and the mineral admixture. The invention further discloses a preparation method of the concrete. The concrete has underwater dispersion-resistant self-leveling property and is not isolated under vibration and underwater environment, and uniform in hole structure uniformity. As a pile body material, the underwater dispersion-resistant porous concrete can realize rapid pulling of a sleeve during vibration immersed tube method construction, generates little disturbance on soil around the pile and does not have pile breakage and hole shrinkage; moreover, the underwater dispersion-resistant porous concrete has good anti-blocking ability.

The hot pressing and blowing process for forming metal bottle is to form metal bottle with high pressure inside a closed mold on the principle that at high temperature, metal material has lowered yield stress and raised plasticity. The forming machine consists of mold seat, side molds, bottom mold, pressure conducting duct and heater. The hot pressing and blowing process for forming metal bottle includes: fixing the bottle blank inside the mold cavity with sealed pressure conducting duct; heating the bottle blank with the heater to the forming temperature and intruding pressure gas into the bottle blank for the bottle blank to be formed into the required shape. The process of the present invention is suitable for forming various kinds of metal containers, including complicated ones, and the formed metal container has homogeneous wall thickness and smooth transition.

According to the invention, a high-strength hot rolled steel sheet having an excellent shape fixability as hot-rolled and an excellent fatigue durability after the forming, excellent weldability and phosphatability and a tensile strength of not less than 590 MPa level can be obtained by comprising C: not less than 0.02 mass % but not more than 0.2 mass %, Si: not less than 0.5 mass % but not more than 2.0 mass %, Mn: not less than 1.0 mass % but not more than 3.0 mass %, Al: not less than 0.01 mass % but not more than 0.1 mass %, N: not less than 0.002 mass % but not more than 0.006 mass %, P: not more than 0.03 mass %, S: not more than 0.01 mass % and solid-soluted (C+N): not less than 0.0010 mass % and the reminder being Fe and inevitable impurities, and having a steel structure that a primary phase is ferrite and a secondary phase is martensite phase of 5-30 % at a volume ratio and a total of both is not less than 95 % as a volume ratio, and further having an average crystal grain size of ferrite of not more than 8 μm.

The invention discloses a resistor heat source-assisted composite double-shaft needle-free friction stir welding method. The method comprises the steps that stirring friction heads are adopted as electrodes of a resistor heat source, high-density currents are provided for the interior of a to-be-welded workpiece through a direct-current switch power supply, and the resistor-assisted heat source is provided for the stirring heads in the friction stir welding process; the stirring heads rotating at a high speed are inserted into the two sides of a joint, and upsetting pressure is exerted to metal at the joint through a shaft shoulder, so that the metal material at the joint is softened; the metal structure at the joint achieves a plasticizing state under the stirring effect through the stirring heads rotating at the high speed, and meanwhile micro-forging treatment is conducted on the plasticized metal by adopting an ultrasonic vibration exciter, so that metal structure crystalline grains at the joint are refined; the stirring heads do feeding motion in the direction of the joint, a cavity formed after a stirring needle moves is continuously filled with the plasticized metal under the stirring and extruding effect of the stirring heads, and the plasticized metal is gradually cooled and solidified to form a final welding joint. According to the method, the life of the stirring heads is prolonged, the welding thickness is increased, the welding speed is increased, and welding defects are reduced.

The invention relates to a green alkali-activated material for repair and protection. The green alkali-activated material is composed of 55%-70% of an alkali-activated active matter, 0-20% of concretewaste slurry powder, 1%-2% of a reinforcing component, 6%-10% of an alkali activator, 1.5%-2% of a water reducing component and the balance water, and the total mass of the green alkali-activated material is 100%. The material is high in early strength, high in fluidity and suitable for construction. Specifically, the concrete waste slurry powder can provide part of excitation alkalinity requiredby an early reaction, aluminosilicate in the waste residue powder has potential alkali-activated active matters, and has a good way of absorbing mixing plant waste residues. The fluidity of a geopolymer can be improved by doping the fly ash and silica fume, the yield stress of the slurry is reduced, and the fluidity required by repair and protection is met. The ultra-dispersed nano reinforcing material is doped, so that the filling effect can be achieved in the alkali-activated reaction process, the dissolution of aluminosilicate minerals is promoted, and the mechanical properties of the alkali-activated material are improved. The green alkali-activated material for repair and protection is low in cost and environmentally friendly, and has high promotable value.

The invention discloses a bottom flow circulating system of a thickener. The bottom flow circulating system comprises a thickening pool, a bottom flow cylinder arranged at the bottom of the thickening pool, a bottom flow circulating pump and a bottom flow discharge pump, wherein the inlet I of the bottom flow circulating pump is connected with the bottom flow cylinder, the outlet I of the bottom flow circulating pump is connected with the thickening pool; and the inlet II of the bottom flow discharge pump is connected with the bottom flow cylinder and the outlet II of the bottom flow discharge pump is connected with a slurry discharging pipeline. According to the bottom flow circulating system of the thickener, through the action of the bottom flow circulating pump, ore slurry flows out from the inside of the bottom flow cylinder to the bottom flow circulating pump and flows back to the thickening pool from the bottom flow circulating pump; the process is repeated again and again, so that the ore slurry at the bottom of the thickener can be forcefully circulated and the occurrence of rake pressing or sticking of the thickener can be effectively prevented; thus the thickener with the bottom flow circulating system has both preparation and storage functions; and besides, the ore slurry of a qualified concentration can be smoothly discharged through the slurry discharging pipeline. The invention further discloses the thickener comprising the bottom flow circulating system.

The invention discloses a chuck power supply auxiliary compound double-axis dynamic friction stir welding method. Positive and negative electrode dynamic clamping heads and a guide pretightening wheel are adopted to finish clamping of workpieces to be welded; a direct-current switch power supply is used for providing high-density current into the workpieces to be welded; metals in joints of the workpieces to be welded are preheated; stirring heads rotating at high speed are inserted in two sides of the joints; positive pressure is applied to the metals in the joints through shaft shoulders, so that the metal materials in the joints are softened; the stirring heads enable the metal structures in the joints to achieve a plastified state under the stirring effect; meanwhile, a ultrasonic exciter is adopted to finely forge the plastified metals, so that grains of the metal structures in the joints are refined; the workpieces to be welded are fed along with a welding worktable in the directions of the joints; and the plastified metals are continuously filled in a cavity formed after movement of stirring needles under the stirring and extruding effects of the stirring heads, and are gradually cooled to condense as welding lines. The method relieves the wear of the stirring heads, increases the welding thickness, accelerates the welding speed, and reduces the welding defects.