52 results about "Gold alloy" patented technology

The invention provides a method for continuously measuring gold, silver, copper, lead and zinc in gold-based alloy, and belongs to the technical field of gold alloy element content detection. According to the method, through combined use of a gravimetric method, an electrolytic method and a titration method, by taking chemical means such as extraction and back extraction, electrochemistry and complex reaction as a theoretical basis, the aim of continuously and accurately measuring gold, silver, copper, lead and zinc in the gold-based alloy can be achieved through one-time sample weighing and sample digestion, the efficiency is improved, the complexity of multiple times of treatment is reduced, and the method is suitable for large-scale popularization and application. The method is accurate and reliable. Different masking agents, buffer reagents, precipitants and the like are selected in a targeted manner to be used in one solution one by one, and the problems that an element method is not applicable, measurement is out of range, and elements interfere with one another are solved.

The invention discloses a 18K gold luster imitation gold alloy suitable for the sculpture field and a preparation method thereof, the 18K gold luster imitation gold alloy comprises the following basic components in percentage by weight: 20-22% of zinc, 10-20% of copper, 10-20% of zinc, 10-20% of copper, 10-20% of copper and 10-20% of zinc. 3%-4% of aluminum; 2%-3% of silicon; 0.9% to 1.9% of nickel; 0.1% of rare earth, and the balance copper and inevitable impurities. The method has the beneficial effects that one-time forming can be directly carried out through conventional copper art sculpture machining modes such as casting and forging, follow-up complicated procedures such as gilding and gilding are not needed, the sculpture production period is greatly shortened, the manual operation difficulty is reduced, and the 18K gold appearance is accurately matched.

A gold alloy and a manufacturing method thereof, the gold alloy including: gold; and an Au-X-RE metamaterial dispersed in a gold matrix, the Au-X-RE metamaterial being represented by a composition formula Au 100‑(a+b) X a RE b represents, in the composition formula, X represents at least one atom selected from the group consisting of Al, Ga, In, Si, Ge, and Sn, RE represents a rare earth element, a and b are contents of X and RE, respectively, represented by at%, satisfy the following (1) and (2), 10 ≤ a ≤ 40 (1) 13 ≤ b ≤ 17 (2).

The present application relates to copper anode slime comprehensive treatment technical field, especially in kind of copper anode slime's purification treatment process. Including the following steps: copper anode slime's pretreatment;Metal gel capture agent's preparation;Vacuum inductive desulfurization of copper arsenic tellurium anode slime is removed;The noble metal of desulfurized anode mud silicon is captured.The present application can increase the mutual contact of silicon dioxide, sodium carbonate, bismuth oxide and carbon fiber and metal elements in desulfurized anode gold mud in three-dimensional space by preparing metal gel capture agent, thereby increasing the contact area, strengthening the slagging reaction of silicon dioxide and sodium carbonate with impurity elements such as arsenic and antimony, and further enhancing the ability of carbon element to reduce bismuth oxide, so that bismuth can better capture gold and silver elements, and impurity metals can better aggregate in the slag, and the obtained bismuth-silver-gold alloy particles have high purity and good metal purification effect.

The embodiment of the invention provides a silver-gold alloy bump structure and a forming method thereof. The method comprises the following steps: providing a semiconductor device; sequentially forming a first seed layer and a second seed layer on the functional surface of the semiconductor device, wherein the second seed layer is an Au seed layer; forming a silver-gold alloy bump on the second seed layer; carrying out annealing treatment on the silver-gold alloy bump and the second seed layer; and removing a part of the first seed layer and a part of the second seed layer through an etching process, so that the first seed layer and the second seed layer are only located between the silver-gold alloy bump and the semiconductor device. Before the seed layer is etched, the silver-gold alloy bump and the Au seed layer are subjected to annealing treatment, so that the hardness of the silver-gold alloy bump is ensured, the lattice structure of Au in the Au seed layer is changed through annealing treatment, the etching rate and effect are improved, the problem of gold residue is solved, and the electrical property and reliability of the silver-gold bump structure are improved.

The application relates to a method for improving the density of a platinum-based powder metallurgy alloy, which realizes the purpose of reducing the porosity of a precious metal powder metallurgy alloy ingot and improving the material density through vacuum melting, powder preparation, resonance compaction, liquid phase sintering, controlled forging and other processes. The above process is adopted, the high-temperature endurance strength and toughness of the platinum-based powder metallurgy alloy are greatly improved, the high-temperature service life of the product is significantly enhanced, and good economic benefits are brought.

The invention belongs to the technical field of welding material design and optimization, and discloses a nickel-based alloy welding rod for a low-temperature service environment and a component design method of the nickel-based alloy welding rod. The welding rod comprises a pure nickel core wire and a coating with a specific formula, the coating comprises CaCO3, CaF2, Cr, Mo, Mn, Si-Fe alloy, Mo-Fe alloy, Nb-Fe alloy and other components, and the mass ratio Cr / Nb of chromium to niobium in deposited metal is controlled to range from 9.16 to 11.68. The invention further provides a corresponding component design method, Cr / Nb is identified as key parameters by constructing a BP neural network model and establishing a mapping relation between chemical components and mechanical properties, and the optimal range of Cr / Nb is reversely deduced through an optimization algorithm. The nickel-based welding rod with high strength (greater than or equal to 680MPa) and high toughness (impact energy greater than or equal to 70J) at the temperature of-196 DEG C can be rapidly and accurately designed, and the nickel-based welding rod is particularly suitable for welding 06Ni9DR and other low-temperature steel.

The present invention relates to the technical field of element content detection, and in particular to a method for determining the gold content and other element contents in a gold alloy product. The method comprises the following steps: 1) dissolving a sample, adding hydrochloric acid, disodium ethylenediaminetetraacetic acid, tartaric acid, oxalic acid, and perchloric acid to prepare a stable sample solution; 2) preparing a calibration solution composed of the main element contents; 3) measuring calibration samples of gold, silver, copper, zinc, nickel, iron, manganese, and chromium with known concentrations to determine the test conditions for the above elements; and 4) testing the calibration solution samples to construct a calibration working curve showing the relationship between X-ray fluorescence spectrum intensity and the gold, silver, copper, zinc, nickel, iron, manganese, and chromium content. The calibration curve is then used to test the sample to determine the gold, silver, copper, zinc, nickel, iron, manganese, and chromium contents in the gold alloy product to be tested. This method can quickly and accurately determine the gold, silver, copper, zinc, nickel, iron, manganese, and chromium contents in gold alloy products with a gold content of 0.15% to 99.9%.

1. Title of the invention Method and system for calculating and controlling the remelting temperature of multi-component alloys 2. Technical field The invention relates to a method for determining and controlling the remelting temperature of alloys in metallurgy, in particular for industrial smelting technology and metal recycling. 3. State of the art Existing methods are based on experimental measurements with stepwise temperature increases, which is energy-intensive and environmentally damaging. 4. Object of the invention The aim is to calculate the remelting temperature based on the chemical composition in order to use energy in a targeted manner, optimize the melting process and reduce environmental impact. 5. Solution to the task The procedure includes: 1. Analysis of the alloy composition, 2. Retrieving melting points from a material database, 3. Calculation of the remelting temperature using the mathematical formulas listed in this patent, 4. Real-time temperature monitoring, 5. Computer-aided control of energy supply. 6. Software can automate the process. 6. Key advantages 1. Reduced energy consumption, 2. Faster melting processes, 3. Improved process control, 4. More efficient metal recycling. 7. Areas of application Use in metallurgy, production and recycling of alloys, and in foundries.

The invention relates to an aluminum alloy single wire and cable manufacturing method and an aluminum alloy cable, and the aluminum alloy single wire and cable manufacturing method comprises the steps that S1, Al is melted and then added into AlB5 alloy to obtain aluminum boride liquid, and the aluminum boride liquid comprises, by weight, 99.7-99.9 wt% of Al and 0.001-0.005 wt% of AlB5 alloy; s2, the aluminum boride liquid is refined, Mg, an AlSi20 alloy, an AlFe20 alloy, an AlTi12 alloy and an AlTi5B1 alloy are added into the aluminum boride liquid after refining, alloy aluminum liquid is obtained, and the alloy aluminum liquid comprises, by weight, 0.006 wt%-0.01 wt% of Mg, 0.003 wt%-0.007 wt% of the AlSi20 alloy, 0.003 wt%-0.006 wt% of the AlFe20 alloy, 0.001 wt%-0.005 wt% of the AlTi12 alloy and 0.003 wt%-0.005 wt% of the AlTi5B1 alloy; s3, refining the molten alloy aluminum, and filtering the refined molten alloy aluminum to obtain molten aluminum to be cast; s4, the molten aluminum to be cast is cast, and a blank is obtained; and S5, the aluminum alloy conducting rod is obtained after the blank is rolled. And S6, stretching the aluminum alloy conducting rod to form the aluminum alloy single wire. According to the aluminum alloy single wire, the manufacturing method of the aluminum alloy cable and the aluminum alloy cable, the tensile strength of the aluminum alloy cable can be improved, and the fracture risk is reduced.

The present invention provides a connection structure comprising: a first circuit component having a plurality of first electrodes; a second circuit component having a plurality of second electrodes; and an intermediate layer having a plurality of junctions electrically connecting the first electrodes and the second electrodes, wherein at least one of the first electrodes and the second electrodes connected by the junctions is a gold electrode, and more than 90% of the plurality of junctions include: a first region connecting the first electrodes and the second electrodes and containing a tin-gold alloy; and a second region in contact with the first region and containing bismuth.

The application discloses a mold for preparing high-porosity spherical porous titanium alloy, which comprises an upper mold punch and a lower mold punch provided with upper half-sphere grooves and lower half-sphere grooves; the upper half-sphere grooves are communicated with each other through upper mold flow channels; and the upper mold punch is further provided with a feeding flow channel. In addition, the application further discloses a preparation method of the high-porosity spherical porous titanium alloy. After titanium powder and other metal element powders are mixed and annealed, the titanium powder is mixed with a binder, and then a spherical blank is prepared by using injection molding equipment and the mold; the spherical blank is subjected to degreasing, sintering and gas suspension smelting in sequence to obtain the high-porosity spherical porous titanium alloy. The porous titanium alloy prepared by the application has high sphericity, smooth surface and relatively dense spherical wall, and the porosity can be controlled according to application conditions, so that the application demands in different fields are met. In addition, the application uses element powder in-situ alloying to prepare the spherical porous titanium alloy, the alloy composition can be freely designed, and batch production can be easily realized.

The invention discloses a gear reducer for an electric drive system of a new energy automobile, which belongs to the technical field of electric drive parts of the new energy automobile and comprises a shell, an input shaft, an output shaft and at least two stages of reduction gear sets arranged between the input shaft and the output shaft. The core innovation points of the gear are as follows: high-alloy carburizing steel or high-strength powder metallurgy alloy is adopted as a gear base material, and carburizing fine grinding and surface strengthening processes such as PVD (Physical Vapor Deposition) coating and laser cladding ceramic layer are combined, so that the hardness, the wear resistance and the antifriction performance of the gear are greatly improved, and the pain points of easy wear and fatigue failure of a tooth surface are solved; meanwhile, the tooth shape of the gear is optimized, the tooth profile with the high contact ratio and the low meshing force angle is adopted, low-viscosity synthetic lubricating oil is matched, an oil way is optimized, and friction and energy loss are reduced; a cooling cavity is integrated in the shell, so that the optimal working temperature of components is guaranteed; the high-performance wear-resistant gear has excellent wear resistance, high transmission efficiency and stability, can reduce the energy consumption of an electric drive system, improves the endurance of a vehicle and the reliability of a power system, and meets the high-performance requirement of a new energy vehicle.

The application discloses a method for producing low-oxygen-content molten steel by adopting an EF+LFV process, wherein 20-30% of weight of slagging materials of smelting raw materials is added with carbon-increasing materials, so that the carbon content of the smelting raw materials reaches 1.20-1.50% of the weight of the smelting raw materials, the oxidation end point temperature is controlled to be greater than or equal to 1630 DEG C, and the carbon content at the oxidation end point is not less than the lower limit of the carbon content required by the smelted steel minus 0.05%; Si-Mn alloy, Si-Fe alloy and carbon-increasing agent are sequentially added into a refining ladle when tapping; and the molten steel is slagged and wire-feeding deoxidized during the refining period; and the molten steel produced by adopting the method has an oxygen content of less than or equal to 20 ppm, so that the purity of the molten steel is ensured to be high, and the production requirements are met.

The present invention discloses a carbon-supported palladium-gold nano-heterogeneous catalyst, a preparation method, and uses thereof. The catalyst comprises a carbon support and active component palladium-gold alloy nanoparticles, with a total metal loading of 3.0 to 15.0 wt.%, including 0.46 to 9.28 wt.% palladium and 1.14 to 12.71 wt.%. The method comprises: 1) dispersing the carbon support in water to obtain a suspension A; 2) adding chloroauric acid to a sodium citrate solution to obtain a suspension B; 3) adding chloropalladic acid to the sodium citrate solution to obtain a solution C; 4) simultaneously adding suspensions B and C to suspension A to obtain a suspension D; 5) ultrasonically treating suspension D, stirring at room temperature, and impregnating the suspension; 6) reducing the suspension with a sodium carbonate solution containing sodium borohydride, filtering, washing, and drying to obtain the catalyst. The method is simple, has mild conditions, and an adjustable ratio of catalytic components. When used for formic acid decomposition to produce hydrogen, the catalyst has the advantages of high catalytic activity, high conversion rate, easy recovery, and multiple uses.

This application discloses a method for manufacturing aluminum alloy wire and aluminum stranded wire, relating to the field of aluminum alloy stranded wire manufacturing technology. The method involves selecting aluminum ingots, magnesium ingots, Al-20Si alloy, Al-20Cr alloy, Al-10V alloy, and lanthanum-cerium mixed rare earth elements as raw materials and smelting them to form an aluminum alloy melt; refining the aluminum alloy melt with inert gas and / or refining agents through in-furnace impurity removal; introducing the aluminum alloy melt into a flow channel integrated with an electromagnetic purification device for external online impurity removal; casting the aluminum alloy melt into an ingot plate, and repeatedly rolling the ingot plate a predetermined number of times using a cumulative rolling method to form an aluminum alloy rod, which is then continuously quenched; allowing the aluminum alloy rod to stand for a predetermined time before drawing it into an aluminum alloy wire, which is then aged to obtain the aluminum alloy wire. Through the above manufacturing method, aluminum alloy wire that meets single-wire tensile strength requirements and has higher conductivity can be prepared with fewer material components.

The invention discloses a magnesium-based rare earth alloy based on electrostatic field-assisted aging heat treatment, which is prepared by the following steps: firstly, preparing an as-cast magnesium-based rare earth alloy through smelting, then, carrying out solid solution treatment to enable a second phase of the as-cast magnesium-based rare earth alloy to be dissolved into a matrix to obtain a solid solution magnesium-based rare earth alloy, and finally, carrying out aging heat treatment at 250 DEG C to obtain the magnesium-based rare earth alloy based on electrostatic field-assisted aging heat treatment. An electrostatic field is connected in the early stage of aging to assist aging treatment; and the precipitation phase proportion can be 45-50% and the hardness can be 90-95 HV by aging for 2 hours in an electrostatic field. The preparation method comprises the following steps: 1, smelting the magnesium-based rare earth alloy; 2, carrying out solution treatment on the magnesium-based rare earth alloy; and 3, carrying out electrostatic field aging treatment on the solid-solution-state magnesium-based rare earth alloy.

Provided is a thermally conductive composition having excellent thermal conductivity and excellent workability. The present invention is a composition containing the following components: (A) 100 parts by mass of gallium and / or an alloy thereof having a melting point of-20 to 100 DEG C; and (B) 2-150 parts by mass of a metal oxide and / or a metal nitride having an average particle diameter of 0.01-200 [mu] m relative to 100 parts by mass of component (A). Wherein the total content of the component (A) and the component (B) in the composition is 95-100 mass%. The gallium alloy of the component (A) in the thermally conductive composition is one or more types selected from the group consisting of a Ga-In alloy, a Ga-Sn-Zn alloy, a Ga-In-Sn alloy, and a Ga-In-Bi-Sn alloy.

The embodiment of the invention provides a silver-gold alloy bump structure and a preparation method thereof. The method comprises the following steps: providing a semiconductor device; a first seed layer and a second seed layer are sequentially formed on the functional surface of the semiconductor device, and the second seed layer is an Au seed layer; forming a silver-gold alloy bump electrically connected with the semiconductor device on the second seed layer; forming a passivation layer on the surface of the silver-gold alloy bump by adopting a plasma passivation process; etching the Au seed layer by adopting a thiourea system etching solution so as to remove part of the Au seed layer; and removing part of the first seed layer. According to the preparation method, the etching rate of the Au seed layer can be improved, corrosion to the silver-gold alloy bump is reduced, a good etching effect is achieved, and the disclosure cost can be maintained; the silver-gold alloy bump structure prepared through the method is free of gold residues and high in reliability.

A high-thermal conductivity composite material is AlNp / ZA27 composite material, including 2%, 4%, 6%, or 8% by volume of aluminum nitride (AlN) ceramic particles and zinc-aluminium-27 (ZA27) alloy. The ZA27 alloy includes 70.52-71.08% by weight of Zn, 25.58˜27.65% by weight of Al, 1.27˜3.45% by weight of Cu, and 0.50% or less by weight of Mg. In the preparation of the high-thermal conductivity composite material, an as-cast AlNp / ZA27 composite material is subjected to homogenizing annealing and reciprocating extrusion.

The invention relates to the technical field of non-ferrous metals, and provides a champagne gold alloy target as well as a preparation method and application thereof. The champagne gold alloy target material provided by the invention is prepared from the following chemical components in percentage by mass: 96 percent to 99 percent of Au, 0.5 percent to 2.4 percent of Fe, 0.3 percent to 0.8 percent of Ag, 0.1 percent to 0.5 percent of In, 0.08 percent to 0.26 percent of Zn, 0.01 percent to 0.02 percent of Nd and 0.01 percent to 0.02 percent of Si. The champagne gold alloy target material is attractive in color and excellent in oxidation resistance and corrosion resistance, the L value of a film plated by the champagne gold alloy target material ranges from 87.2 to 88.5, the a value ranges from 1.3 to 6.4, the b value ranges from 20.4 to 34.2, the champagne gold alloy target material does not change color in an artificial sweat test for 360-432 h, the champagne gold alloy target material does not change color in a salt spray test for 240-360 h, market requirements can be met, and the champagne gold alloy target material is wide in application prospect.

Method for manufacturing a bipolar plate (2), comprising the following steps: - Provision of two steel half-sheets (3, 4), wherein at least one of the two half-sheets (3, 4) has an embossed structure (5), - Construction of a three-dimensional metal structure (7) from a first powder (12) of a metal different from the steel of the half-sheets (3, 4) or from at least two powders (12) of different metals, wherein at least one first powder of the at least two powders (12) is selected to be different from the steel of the half-sheets (3, 4), wherein the metal is selected from the group comprising titanium, titanium alloys, nickel, nickel alloys, chromium, chromium alloys, ferrochrome alloys, copper, copper alloys, gold, gold alloys, platinum, platinum alloys, silver, silver alloys, iridium, iridium alloys, rhodium, rhodium alloys, ruthenium, ruthenium alloys, palladium, palladium alloys, on a first half-sheet (3) of the two half-sheets (3, 4) by means of a laser (10) with green laser light and consequently a wavelength in the range of 495 nm to 550 nm, wherein the first Powder made from the metal copper is used.wherein, when using at least one further different second powder, a further laser in the form of an infrared laser is used to build up the three-dimensional metal structure (7), and , - Forming a materially bonded connection of the 3D metal structure (7) with a second half-sheet (4) of the two half-sheets (3, 4) using the same laser (10) with green laser light, wherein the half-sheets (3, 4) are joined to form a bipolar plate (2).

To provide an Au alloy that includes an Au-based hypermaterial and that achieves higher hardness than the prior art while retaining a high Au content.SOLUTION: The present invention relates to a high-hardness Au alloy including an Au-rich phase and an HM phase composed of an Au-X-RE-based hypermaterial represented by the following formula. In the Au alloy according to the present invention, in a material structure at an arbitrary cross section, the Au-rich phase having an average equivalent circle diameter of 1.5 μm or less is distributed. In the above formula, X is at least one atom selected from the group consisting of Al, Ga, In, Si, Ge, and Sn. RE is a rare earth element. a represents a content of X in atom%, and satisfies 5≤a≤40, and b represents a content of RE in atom%, and satisfies 11≤b≤18.SELECTED DRAWING: Figure 1

The invention provides a bipolar current collector and a preparation method and application thereof. The bipolar current collector sequentially comprises an aluminum layer, a buffer layer and a copper layer, the buffer layer is made of alloy, the alloy comprises at least one of Ni-W alloy, Ni-P alloy, Co-W alloy and Fe-Cr-B alloy, the thermal expansion coefficient of the alloy is 9-16 (* 10 <-6 > / K), and the microhardness of the alloy is 600-1300 HV. The bipolar current collector can effectively solve the problem that the interface bonding strength of the copper layer and the aluminum layer in the existing bipolar current collector is weak, so that the conductivity, the mechanical strength and the electrochemical stability of the bipolar current collector can be effectively improved.

The utility model discloses a ceramic circuit board which comprises a ceramic substrate, a metal substrate layer and a contact layer, the metal substrate layer is located between the ceramic substrate and the contact layer, the contact layer is sequentially provided with a nickel layer, a gold layer, a platinum layer and a tin-gold alloy layer from inside to outside, the nickel layer covers the surface of the metal substrate layer, the gold layer covers the surface of the platinum layer, and the tin-gold alloy layer covers the surface of the metal substrate layer. The gold layer is located between the nickel layer and the platinum layer, and the tin-gold alloy layer covers the outer surface of the platinum layer. According to the ceramic circuit board provided by the invention, the black nickel or black pad phenomenon generated in the circuit board is effectively reduced, the reliability and stability of the ceramic circuit board are improved, the stability of signal transmission and power supply transmission is improved and stabilized, the use amount of the gold element is reduced, so that the production cost is reduced, and the ceramic circuit board has a wide application prospect.

The invention discloses a manufacturing method of a thin-wall aluminum-copper metallurgical composite pipe, which is characterized in that the composite pipe comprises a bottom-layer aluminum pipe, a metallurgical alloy layer positioned outside the aluminum pipe, an outer-layer copper layer positioned outside the metallurgical alloy layer and a surface layer, and the metallurgical alloy layer is formed by heating the surface of the aluminum pipe through laser to enable the aluminum surface to reach a molten state. Meanwhile, the copper material is heated to be in a molten state and then sprayed to the surface of the aluminum, so that the copper and the aluminum form a micron-sized alloy layer; and the outer copper layer is formed by laser cladding. The outer copper layer enables the bottom layer aluminum pipe to be in complete contact with the outside, the service life is long, the heat conduction effect is close to that of the copper pipe, the micron-sized metallurgical alloy layer enables the aluminum-copper shear strength to be greatly improved, copper-aluminum potential corrosion is eradicated, and the surface macromolecule modified silane nano composite layer improves the corrosion resistance; and the wall thickness can be controlled between 0.6 mm and 0.8 mm.

The invention discloses a screening method of an Mg-Ni-Y hydrogen storage alloy containing an Mg2Ni phase and a 14H-LPSO phase. The screening method comprises the following steps: 1, carrying out high-flux thermodynamic calculation on the theoretical hydrogen storage capacity of the Mg-Ni-Y alloy; 2, establishing a hydrogen storage performance data set of the Mg-Ni-Y alloy; 3, Mg-Ni-Y alloy screening conditions are set, and the hydrogen storage performance of the target alloy is set to meet the three screening conditions at the same time; and 4, determining a phase component region meeting screening conditions. The Mg-Ni-Y hydrogen storage alloy with high hydrogen storage capacity and rapid hydrogen absorption and desorption is obtained through screening, and the alloy element components comprise, by atomic percent, 8.5-10 at.% of Ni, 1.5-2.5 at.% of Y and the balance Mg; the phase composition of the alloy is an Mg phase, an Mg2Ni phase and a 14H-LPSO phase. When the material is used as a magnesium-based hydrogen storage material, the initial hydrogen desorption temperature is less than 210 DEG C; the maximum reversible hydrogen storage capacity is 5.5 to 6.5 wt.%; the hydrogen absorption rate is 0.27 to 0.29 wt.% / min; the hydrogen desorption rate ranges from 1.57 wt.% / min to 1.65 wt.% / min; and when the cycle index exceeds 500 times, the hydrogen storage capacity is not attenuated.

The application provides a method for continuously determining gold, silver, copper, lead and zinc in a gold-based alloy, and belongs to the technical field of gold alloy element content detection. The method is based on the combination of the weight method, the electrolysis method and the titration method, and is based on the chemical means such as extraction, back extraction, electrochemistry and complex reaction, and through one-time sample weighing and sample digestion, the continuous and accurate determination of gold, silver, copper, lead and zinc in the gold-based alloy can be realized, the efficiency is improved, the complexity of multiple treatments is reduced, and the method is accurate and reliable. Through the targeted selection of different masking agents, buffer reagents and precipitating agents used one by one in one solution, the problems of unsuitable element method, determination out of range and mutual interference between elements are solved.

The utility model discloses a high-performance electric appliance metal composite contact structure, which relates to the technical field of electrical equipment and comprises an electric appliance base, a closed electric appliance is movably mounted at the left end of the electric appliance base, a contact is arranged inside the right side of the closed electric appliance, and a contacted point is arranged inside the left side of the electric appliance base. The contact and the contacted point are made of copper alloy base materials with excellent electrical conductivity and thermal conductivity, the mechanical strength is moderate, the copper alloy base materials are provided with the gold alloy base layers which are used for special application in an extreme environment, the contact shows excellent stability and wear resistance at high temperature, and the contact has high electrical conductivity and oxidation resistance. Silver electroplating is carried out on the surface of the copper alloy base material of the contact and the contacted point to form a uniform and compact silver plating layer, the thickness of the silver plating layer is micron, and it is ensured that the contact has excellent conductivity, abrasion resistance and oxidation resistance. The structure can be widely applied to the fields of electric power, industrial automation, household appliances and the like, and equipment reliability and service life are improved.

The application provides a kind of firebrick for steelmaking furnace lining and a preparation method thereof, and the firebrick comprises the following components and the mass percentage of each component is as follows: 35-40% of macrocrystalline fused magnesia; 20-25% of coarse fused magnesia; 15-20% of fine fused magnesia; 4-8% of fused spinel; 4-8% of sintered spinel; 4-8% of bimodal alumina; 5-10% of AlSi12 alloy; 2-5% of Al-Mg alloy; and 2-5% of boron carbide, and the sum of the mass percentages of the components is 100%. The firebrick can be used in steel desulfurization smelting, is suitable for different desulfurization requirements and different smelting conditions, and has the advantages of long service life, good corrosion resistance and peeling resistance.