53 results about "Gunmetal" patented technology

The invention relates to a special copper-tin alloy material and a preparation method and application thereof. The special copper-tin alloy material comprises the following elements in percentage by mass: 6.0-10.0% of Sn; 0.05 to 0.5 part of Ni; zn: < = 5.0; mn < = 0.5; 0.2 to 1.0 part of Co; pb: < = 1.0; al < = 0.25; si < = 0.05; and the balance of copper and inevitable impurities. The tensile strength of the special copper-tin alloy material ranges from 360 MPa to 560 MPa, the yield strength ranges from 200 MPa to 350 MPa, the hardness ranges from 120 HB to 180 HB, the ductility is larger than or equal to 20%, and the special copper-tin alloy material further has the advantages of abrasion resistance, friction reduction, sintering resistance, corrosion resistance and good burying property and thermal conductivity.

The invention discloses a method for preparing a copper-tin alloy coating on the surface of steel through ultrahigh-speed laser cladding, which comprises the following steps of: S1, pretreating a steel substrate, and controlling the surface roughness Ra to be 2.5-3.2 microns; s2, spherical copper powder and flaky tin powder with the particle size of 15-53 microns are taken, and the copper powder is treated through microwave plasma, so that a nanoscale copper oxide layer is formed on the surface of the copper powder; s3, tin powder and the activated copper powder serve as coating raw materials, an airborne double-barrel powder feeder is adopted, laser is in a flat-top type circular light spot mode, a steel substrate moves relative to a laser cladding device according to a set track, the laser power is 3.5-4.5 kW, the laser scanning speed is 50-80 m / min, and the copper powder is molten into a liquid state to wrap the tin powder; and the temperature of the molten pool is monitored in real time, so that the temperature is stabilized at 1300-1400 DEG C, and finally the copper-tin alloy coating is prepared on the surface of the steel substrate. According to the method, efficient, high-precision and low-defect manufacturing of the copper-tin alloy coating is achieved through a light-powder-matrix coordinated regulation and control mechanism.

The alloy wire comprises the following components in percentage by mass: 0.1 to 6.0 weight percent of Sn, 0.1 to 0.3 weight percent of Ag, 0.01 to 0.20 weight percent of Zr, 0.02 to 1.00 weight percent of Y, 0.02 to 2.00 weight percent of Ce, 0.01 to 0.80 weight percent of Eu, 0.01 to 0.50 weight percent of Rb, Y / (Ce + Eu + Rb) is more than or equal to 0.8 and less than or equal to 1.2, and the balance of Cu and inevitable impurities of which the total amount is less than or equal to 0.05 weight percent. According to the invention, Ag and Zr are added into the copper-tin alloy wire in component design, and composite rare earth elements are also added, so that the addition amount of each rare earth element is limited, and in order to further improve the processability and comprehensive performance of the alloy wire, the addition amount of each rare earth element is limited; and finally, the preparation process of vacuum melting-continuous casting technology-multi-pass drawing combined with on-line dynamic annealing process treatment is combined, so that work hardening and internal stress of the wire are eliminated, the machining precision, plasticity and conductivity of the wire are improved, the material performance is more uniform, and the subsequent deformation or cracking risk in use is reduced.

The invention relates to the field of diamond saw blades, and discloses a diamond saw blade and a preparation method thereof.The saw blade comprises a cutter body and a cutter bit, and the cutter bit is prepared from, by mass, 10-25 parts of diamond particles; 18 to 25 parts of cobalt powder; 15 to 28 parts of tungsten powder; 8 to 14 parts of nickel powder; 15 to 22 parts of copper powder; 8 to 14 parts of iron powder; 8 to 12 parts of copper-tin alloy; 2-5 parts of manganese powder; and 0.5-2 parts of a heat-resistant phase. The diamond particles are subjected to multi-particle-size grading matching, so that coarse particles guide cutting, fine particles fill gaps of the coarse particles, a compact structure is formed, and the effect of improving the density of the tool bit and the cutting stability is achieved. Compared with a formula only using single-particle-size diamond particles in the prior art, the problems of loose particle accumulation, stress concentration and easy cracking are solved.

The invention discloses a method for recycling tin and copper resources in copper dross through a gas phase oxidation-reduction roasting two-step method, and relates to the field of secondary resource recycling. The method comprises the following steps: firstly, grinding and mixing the copper dross and a slag former, feeding into a smelting furnace, and carrying out selective oxidation smelting, so that a gas oxidizing agent and tin, lead, copper, arsenic and sulfur phases in the copper dross are subjected to selective oxidation reaction, tin, arsenic and copper enter a dross phase, most lead is distributed in a crude lead phase, sulfur is oxidized into sulfur dioxide and enters a gas phase; selective oxidation slagging and efficient separation of tin and copper are achieved; then smelting slag and a reducing agent are evenly mixed according to a certain proportion and put into a rotary kiln to be subjected to reduction roasting, tin, arsenic, copper and other components in the smelting slag are synchronously subjected to a reduction reaction, arsenic can be reduced into arsenic oxide to be volatilized and enriched in smoke dust, tin and copper are reserved in roasting slag, and copper-tin alloy is generated through reduction smelting; the method disclosed by the invention has the advantages of simplicity in operation, low cost and the like, and has a good popularization and application prospect.

The invention relates to a copper-tin alloy electroplating solution for barrel plating. The copper-tin alloy electroplating solution for barrel plating comprises the following components in parts by mass: 80 g / L to 120 g / L of hydrochloric acid, 15 g / L to 25 g / L of copper chloride, 10 g / L to 30 g / L of stannous chloride, 15 g / L to 25 g / L of stannous pyrophosphate, 15 g / L to 35 g / L of copper pyrophosphate, 5 g / L to 10 g / L of sodium chloride, 20 g / L to 40 g / L of succinimide, 0.01 g / L to 0.02 g / L of sodium citrate, 40 g / L to 60 g / L of a complexing agent, 0.2 g / L to 0.6 g / L of a brightening agent, 4 g / L to 8 g / L of a dispersing agent, 0.1 g / L to 0.2 g / L of a stabilizing agent and 30 g / L to 50 g / L of a buffering The copper-tin alloy electroplating solution for barrel plating is a cyanide-free electroplating solution, and the influence on the environment is greatly reduced in the production process. The copper-tin alloy electroplating solution for barrel plating can form a compact plating layer on a plating piece, and the bonding performance of the plating layer and the plating piece is stable, so that a protective layer with corrosion resistance and friction resistance is formed on the surface of the plating piece.

The utility model discloses a container with sealing structure, including container body, copper ring and tin solder plug, the one side of container body is provided with the opening, is provided with copper ring in the opening, and the outer wall of copper ring is sealedly connected with the opening, and the middle of copper ring is provided with the injection hole, and tin solder plug sets up in the injection hole, and covers the outer surface of copper ring, this scheme sets up in the opening through copper ring, and carries out sealed and forms the injection hole, and cooperates with tin solder plug and realizes the injection hole sealing, utilizes the excellent wettability and metallurgical reaction of soldering tin to copper surface, forms the small dense alloy layer at interface, can improve the sealing effect, copper is strong inert metal as simultaneously, and its surface oxide layer is stable, and tin solder plug and copper tin alloy layer chemical property are mild, and all are not easy to have the corrosion, dissolution or component mutual solubility with organic phase change material, avoid the physicochemical reaction problem of traditional glue seal / block seal, further promote the sealing stability.

The invention discloses a high-strength and high-conductivity copper-tin alloy wire resistant to high-temperature softening and a preparation process thereof. The high-strength and high-conductivity copper-tin alloy wire comprises the following raw materials in percentage by mass: 0.25-0.35 wt.% of Sn; according to the Cu-Sn-Zr alloy wire, the tensile strength is 700 MPa or above, the electric conductivity is higher than 75% IACS, the softening-resistant temperature reaches 400 DEG C or above, the use requirement of the high-strength and high-conductivity Cu-Sn alloy wire at the high temperature can be met, and after deformation heat treatment of an alloy rod is completed, the tensile strength of the alloy rod is larger than or equal to 700 MPa, the electric conductivity is higher than 75% IACS, and the softening-resistant temperature reaches 400 DEG C or above; and the alloy bar is subjected to gradient cooling treatment through special gradient cooling equipment, so that the problems of hot cracks and the like in the cooling process are avoided, and the quality of the finished alloy bar is ensured.

The utility model relates to the technical field of mechanical equipment, in particular to a durable hydraulic prop which comprises a hydraulic prop body, a plating layer is arranged outside the hydraulic prop body, the plating layer is a composite plating layer of a copper-tin alloy plating layer and a chromium plating layer, and a passivation zinc plating layer is further arranged outside the chromium plating layer. A hard chromium plating layer is arranged between the chromium plating layer and the copper-tin alloy bottom layer; or a milky white hard chromium plating layer is arranged between the chromium plating layer and the copper-tin alloy bottom layer. The hydraulic prop has the advantages of being more durable and free of dust adhesion.

The application discloses a high-strength and high-conductivity copper-tin alloy wire capable of resisting high-temperature softening and a preparation process thereof, and the copper-tin alloy wire comprises the following raw materials in percentage by mass: Sn 0.25-0.35 wt.%; Zr 0.15-0.35 wt.%, and the balance of Cu and inevitable impurities. The Cu-Sn-Zr alloy wire has a tensile strength of more than 700 MPa, an electrical conductivity of more than 75% IACS, and a softening resistance temperature of more than 400 DEG C, and can meet the use requirements of the high-strength and high-conductivity Cu-Sn alloy wire at high temperature. After deformation heat treatment of the alloy rod is completed, the alloy rod is subjected to gradual cooling treatment through a special gradual cooling device, so that problems such as thermal cracks in the cooling process are avoided, and the quality of the alloy rod product is ensured.

The invention relates to a high-strength, high-conductivity and low-dislocation-density copper alloy wire for signal transmission and connection and a preparation method of the high-strength, high-conductivity and low-dislocation-density copper alloy wire. The fine control problems of uneven components and structures during casting, grain orientation / microdefects in the forming process and the like are solved, the wire has good machining performance, and the wire still has good mechanical and electrical properties after subsequent machining.

The utility model provides a chamfering grinding wheel with a reinforcing layer, and relates to the technical field of grinding wheel manufacturing, the chamfering grinding wheel comprises a base body, the base body is provided with a mounting hole, and the base body is made of aluminum alloy; the grinding layer is arranged on the periphery of the base body, the grinding layer is formed by sequentially connecting a plurality of diamond layers and a plurality of metal reinforcing layers, the metal reinforcing layers are arranged on the two end faces of the grinding layer, and the thickness of the metal reinforcing layers arranged on the two end faces of the grinding layer is larger than the thickness of the metal reinforcing layers between the diamond layers. Chamfering grooves are formed in the outer side walls of the diamond layers, and the metal reinforcing layer is a copper-tin alloy layer. In the using process of a traditional chamfering grinding wheel, edges of a grinding layer are prone to being damaged when encountering external force, chamfering grooves are damaged, and the machining efficiency and the overall service life are affected. The metal reinforcing layer is arranged in the grinding layer, so that the chamfering groove can be protected, the machining efficiency of the grinding wheel can be improved, and the overall service life of the grinding wheel can be prolonged.

The invention belongs to the technical field of copper-tin alloy contact wire preparation, and relates to a casting process of a casting rod for a copper-tin alloy contact wire, the copper-tin alloy contact wire and a preparation process of the copper-tin alloy contact wire. The casting technology comprises the following steps that a cathode copper plate and a tin block are added into a smelting device to be smelted, in the smelting process, a refining agent is added, the surface of molten metal is covered with graphite, and a copper-tin alloy cast rod is cast; the refining agent comprises sodium chloride, borax, sodium carbonate and fluorite; the adding mass of the sodium chloride is 0.02%-0.05% of the weight of the cathode copper plate, the adding mass of the borax is 0.15%-0.20% of the weight of the cathode copper plate, the adding mass of the sodium carbonate is 0.02%-0.05% of the weight of the cathode copper plate, and the adding mass of the fluorite is 0.12%-0.25% of the weight of the cathode copper plate. Various refining agents are added, copper liquid is purified, harmful impurities are removed, and the problem that an existing copper-tin alloy contact wire cannot meet high strength and high conductivity at the same time is solved.

A tin-plated product, wherein a surface of a substrate (10) is plated with tin, the tin-plated product comprising: a substrate (10) made of copper or a copper alloy; a base (12) formed on a surface of the substrate (10), the base (12) being formed of nickel and / or a copper-nickel alloy; and an outermost layer formed on a surface of the base layer (12), the outermost layer being composed of a copper-tin alloy layer (14) and tin layers (16), the copper-tin alloy layer (14) being formed of a large number of crystal grains of a copper-tin alloy, each of the tin layers (16) being arranged in a corresponding one of depressed portions, each of which is formed between adjacent crystal grains of the large number of crystal grains of the copper-tin alloy, the adjacent crystal grains being adjacent to each other on an outermost surface of the outermost layer, wherein an area ratio occupied by the tin layers (16) on the outermost surface is 20 to 80%, and a maximum thickness of the tin layers (16) is smaller than an average particle diameter of the crystal grains of the copper-tin alloy, and wherein the outermost surface has an arithmetic mean roughness Ra of 0.05 to 0.2 micrometers and a maximum roughness depth Ry of 0.3 to 1.5 micrometers.

To provide a thermosensitive pellet type thermal fuse having a low risk of a short circuit or the like of a circuit caused by tin plating applied to a lead wire even when placed in a high temperature environment.SOLUTION: A case having an internal space; two lead wires provided at respective ends of said case and connected to a circuit; and a thermal pellet and an electrical contact provided in said internal space, said thermal pellet melting at a predetermined operating temperature or higher; A temperature fuse configured such that the electric contact is disconnected to interrupt a circuit, wherein at least one of the two lead wires includes a core material formed of copper or a copper alloy and a covering portion covering the core material, and the covering portion includes a tin layer formed as an outermost layer and a copper-tin alloy layer formed between the tin layer and the core material.SELECTED DRAWING: Figure 5

The aim is to achieve both reduced insertion force and improved solder wettability in high-temperature, high-humidity environments. [Solution] The average thickness of the nickel layer is 0.15 mm or more and 4.0 mm or less, and the average thickness of the copper-tin alloy layer is 0.15 μm or more and 0.8 μm or less. In a cross section parallel to the rolling direction of the substrate, if the area ratio of the tin layer to the total area of ​​the copper-tin alloy layer and tin layer at the connection point is X%, and the area ratio of the tin layer to the total area of ​​the copper-tin alloy layer and tin layer at the soldering point is Y%, then X% is 21% or more and 50% or less, Y% is 31% or more and 90% or less, Y > X, and the difference between them is 10% or more.

The invention discloses a magnesium alloy gold plating method with triple electrochemical protection effects and a plating layer structure. The process comprises the following steps: sequentially preparing a chemical zinc deposition layer, a cyanide-free copper-tin alloy plating layer, a cyanide-free copper-zinc alloy plating layer, a bright nickel-copper alloy plating layer, a nickel-phosphorus alloy plating layer, a gold plating layer and an anti-discoloration protective film on a magnesium alloy substrate. According to the cyanide-free copper-tin alloy plating process, 18-24 g / L of polycuprous thiocyanate, 0.2-0.6 g / L of stannous oxalate, 130-170 g / L of polysodium thiocyanate, 20-30 g / L of sodium 1-hydroxyethylidene-1, 1-diphosphonate and 8-12 mL / L of a copper-tin alloy plating brightener are adopted, the pH value of a plating solution is 12-13, the temperature of a plating tank is 30-40 DEG C, the cathode current density is 0.5-1.5 A / dm < 2 >, the cathode movement speed is 3-5 m / min, oxygen-free electrolytic copper particles serve as an anode, the copper particles are loaded into a titanium anode basket, the area ratio of the anode to the cathode is larger than 3: 1, and the anode movement speed is 3-5 m / min. And the surface of a plated part is not rusted after the plated part is subjected to an acetate mist test for 200 hours according to the GB / T 10125-2021 standard.

This invention relates to the field of COF carrier technology, and more particularly to a COF carrier and its preparation method. The preparation method includes the following steps in sequence: coating, exposure, development, etching, micro-etching, first chemical tin plating, first baking, solder resist printing, second chemical tin plating, and second baking; wherein, the tin layer thickness of the first chemical tin plating is 0.05~0.08μm; the first baking makes the tin layer completely become a copper-tin alloy; solder resist printing uniformly prints a layer of ink on the non-lead area of ​​the carrier; and the second chemical tin plating is performed only on the lead area of ​​the carrier. This invention, by adjusting the production process and unfolding sequence of the COF carrier, and through the micro-etching process after desmearing and the second tin plating process, increases the copper content and reduces the amount of copper-tin alloy formed by the structural design of the COF carrier, thereby increasing the pure copper ratio of the circuit, improving the heat dissipation capacity of the COF carrier, and enhancing the packaging and testing efficiency of the COF carrier at the packaging and testing end.

The invention discloses a method for preparing a high-performance copper-tin-10 alloy powder, which belongs to the field of alloy powder production. The electrolytic copper plate with a composition ratio of 87% and the tin ingot with a composition ratio of 13% are smelted together to obtain a copper-tin-13 alloy liquid; then, the copper-tin-13 alloy powder is prepared by high-pressure water atomization and centrifugal dehydration; after the powder is dried, it is mixed with the electrolytic copper powder in proportion to form a copper-tin primary mixed powder. This powder is diffused and reduced in a nitrogen-hydrogen environment in a reduction furnace to convert it into a copper-tin-11 alloy aggregate with a tin content of 10.5-11.5%; then, the aggregate is crushed and sieved to 80 mesh to obtain a copper-tin-11 alloy powder, and is mixed again with additional pure copper powder, phosphor copper powder and lubricant for 40 minutes to produce a finished copper-tin-10 alloy powder; finally, the finished product is packaged after passing the sintering test. This method optimizes the performance of the alloy powder, the green strength is much higher than the powder prepared by the direct diffusion method, and the sintering shrinkage rate is also better than the powder prepared by the direct diffusion method, and has better crushing strength.

The invention discloses a method for preparing a composite blank for a Ni3Sn superconducting wire based on copper-tin alloy powder. The method comprises the following specific steps: preparing Cu-Sn-Ti alloy powder by adopting a gas atomization method; carrying out surface treatment on the plurality of pure niobium rods; the Cu-Sn-Ti alloy powder and the pure niobium rod are assembled in a mold, and a Cu-Sn-Ti / Nb rod combined blank is obtained; and the Cu-Sn-Ti / Nb rod combined blank is placed in a vacuum rapid hot pressing furnace to be subjected to heat-force-electricity synergistic sintering and cooled, and a CuSnTi / Nb composite blank is obtained. The plasticity of the composite blank for the Nb3Sn superconducting wire obtained by the method is improved, and cracking in the subsequent multi-pass drawing process is avoided.

The present application relates to the field of diamond tools, and specifically discloses a matrix material for diamond tool heads, a sharp diamond uniformly distributed saw blade, and a preparation process thereof. A matrix material for diamond tool heads comprises the following raw materials in weight percentage: 50-60% dendritic electrolytic copper powder, 20-40% copper-tin alloy, 0-5% cobalt powder, 0-15% tin powder, and 5-10% iron powder; the diamond saw blade comprises a disc-shaped base and a diamond tool head, and the circumference of the diamond tool head is concave inward; the diamond tool head is provided with two drainage grooves running through the surface of the diamond tool head, and the two drainage grooves intersect or are parallel to each other. When intersecting, the intersection point is located on the side of the diamond tool head close to the disc-shaped base, and a U-shaped groove is provided on the circumference of the diamond tool head away from the disc-shaped base. The matrix material of the present application has a high holding force on the diamond particles and can accurately position them; in addition, the diamond saw blade of the present application has high cutting efficiency, good sharpness and self-sharpening properties.

Tinned product, comprehensive: a base material (10) made of copper or a copper alloy; a copper-tin alloy layer (12) formed on the base material (10), and a tin layer (14) formed on the copper-tin alloy layer (12), wherein the tinned product has a luster of 0.3 to 0.7 and the outermost surface of the tinned product has a mean height Rc of 0.1 to 1.0 µm.

The invention belongs to the field of metallurgy, and particularly relates to a dispersion strengthened copper-tin alloy and a preparation method and application thereof. The method comprises the following steps: 1) preparing an aluminum-containing aqueous solution, putting copper oxide into the aluminum-containing aqueous solution, mixing, and continuously stirring until the mixture is pasty to obtain a pasty material; 2) oxidizing and calcining the pasty material to obtain a copper aluminum oxide mixture; and (3) the copper-aluminum oxide mixture is subjected to reduction calcination, aluminum oxide dispersion copper alloy powder is obtained, the aluminum oxide dispersion copper alloy powder and tin powder are mixed and then subjected to diffusion alloying treatment, and the dispersion strengthened copper-tin alloy is obtained. Micro-level combination of copper and aluminum is achieved through a special process, the copper-tin alloy can be effectively and flexibly constructed on the basis, and it is ensured that the copper-tin alloy has good physical and chemical properties.

A method for preparing an ultra-long copper-tin alloy fine wire comprises the following steps: 1) weighing 99.4-99.9% copper and 0.1-0.6% tin by weight, and smelting them into ingots; 2) continuously casting the ingots into copper-tin alloy rods; 3) cold forging the copper-tin alloy rods for multiple passes, and heat treating when the deformation of the copper-tin alloy rods reaches 65%-75%, to obtain copper-tin alloy wire rods; 4) drawing the copper-tin alloy wire rods for multiple passes into copper-tin alloy fine wires. The copper-tin alloy fine wires change the cast structure appearing during continuous casting by cold forging, so that the wire structure is uniform and fine, has high tensile strength and high conductivity, and the structure is deformed in a coordinated manner during the wire drawing process, and is not easy to break. When the wire diameter is 0.03mm, the tensile strength is greater than 1000MPa, the conductivity is greater than 82%IACS, and the length of a single filament reaches 300,000 meters, accounting for no less than 85% of the total, with high production efficiency and excellent continuous processing capability.

In the present invention, the average thickness of a nickel layer is 0.15-4.0 mm, and the average thickness of a copper-tin alloy layer is 0.15-0.8 μm. In a cross section parallel to a rolling direction of a base material, when the area ratio of a tin layer to the total area of the copper-tin alloy layer and the tin layer of a connection part is taken as X% and the area ratio of the tin layer to the total area of the copper-tin alloy layer and the tin layer of a soldering part is taken as Y%, X % is 21%-50%, Y % is 31%-90%, Y > X, and a difference therebetween is 10% or more.

To provide a conductive material that possesses sufficient heat resistance while enabling sufficiently low contact resistance under low contact pressure (<2 N).SOLUTION: A conductive material having a base material made of copper or a copper alloy, one or more ground layers each composed of one or more elements selected from the group consisting of Ni, Co, and Fe, a Cu-Sn alloy layer, and a Sn layer in the given order where the skewness evaluated with a cutoff value of 25 μm in a 250 μm square area containing 50% or more of the Sn layer on the Sn layer side surface of the conductive material is -3.50 to 3.50.SELECTED DRAWING: Figure 1A

The invention discloses a magnesium alloy nickel plating process with triple electrochemical protection effects and a plating layer structure. The process comprises the step of sequentially preparing a chemical zinc deposition layer, a cyanide-free copper plating layer, a cyanide-free copper-tin alloy plating layer, a cyanide-free copper-zinc alloy plating layer, a bright nickel plating layer and an anti-discoloration protective film on a magnesium alloy matrix. According to the cyanide-free copper-tin alloy plating process, 18-24 g / L of polycuprous thiocyanate, 0.2-0.6 g / L of stannous oxalate, 130-170 g / L of polysodium thiocyanate, 20-30 g / L of disodium 1-hydroxyethylidene-1, 1-diphosphonate and 8-12 mL / L of a copper-tin alloy plating brightener are adopted, the pH value of a plating solution is 12-13, the temperature of a plating tank is 30-40 DEG C, the cathode current density is 0.5-1.5 A / dm < 2 >, the cathode movement speed is 3-5 m / min, oxygen-free electrolytic copper particles serve as an anode, the copper particles are loaded into a titanium anode basket, the area ratio of the anode to the cathode is larger than 3: 1, and the anode movement speed is 3-5 m / min. And the surface of a plated part is not rusted after the plated part is subjected to an acetate mist test for 96 hours according to the GB / T 10125-2021 standard.

The application discloses a copper-tin alloy powder and a preparation method thereof. The copper-tin alloy powder is spherical and has 3-level pores, and the loose bulk density is 1.8-2.9 g / cm 3 The 3-level pores are as follows: the first-level pore size is 20-200 µm; the second-level pore size is 5-30 µm; and the third-level pore size is 0.5-10 µm. The strength of the powder compact prepared by the method is high. During the pressing process, the metal powder is deformed, and the powder is attached together. The lower the loose bulk density of the powder is, the larger the attached area is, and the better the strength of the green compact is. The strength of the bronze green compact prepared by the method is very high, and the strength of the green compact is 6-12 MPa.

It can be applied to various copper-based substrates, suppressing void formation, reducing the coefficient of friction, and preventing film peeling under prolonged high-temperature conditions. [Solution] A film is formed on the surface of a substrate made of copper or a copper alloy, and the film has a nickel layer made of nickel or a nickel alloy formed on the surface of the substrate, a copper-tin alloy layer made of a copper and tin alloy formed on the nickel layer, and a tin layer made of tin or a tin alloy formed on the copper-tin alloy layer, the average thickness of the nickel layer is 0.15 μm or more and 3.00 μm or less, the average thickness of the copper-tin alloy layer is 0.2 μm or more and 1.0 μm or less, the average thickness of the tin layer is 0.1 μm or more and 2.0 μm or less, and the copper-tin alloy layer contains a Cu6Sn5 alloy, and the average GOS value of the Cu6Sn5 alloy in a cross section parallel to the rolling direction of the substrate is 0.48° or more and 0.70° or less.

The present application relates to the technical field of circuit board processing, and specifically discloses an environmentally friendly tin stripping water for stripping the copper-tin alloy layer of a printed circuit board, the tin stripping water comprising the following raw materials in weight percentage: 25-65% sulfuric acid, 2-10% hydrogen peroxide, 0.5-3% citric acid, 0.5-6% boric acid, 0.1-2% stabilizer, 0.1-2% copper protector, and the balance being deionized water; the tin stripping water provided in the present application has a scientific formula, a rigorous ratio, and is simple to prepare; the obtained tin stripping water has stable performance and can be used in a tin stripping process to achieve one-step stripping of excess tin layer and copper-tin alloy layer, with the advantages of high tin biting rate, large tin dissolving amount, low copper biting rate, fast copper-tin alloy layer stripping rate, thorough stripping without damaging the copper surface; the tin stripping water formula of the present application does not contain nitric acid with strong corrosiveness and irritation, and no strong irritating gas is generated during the production and tin stripping process; the obtained tin stripping waste liquid is convenient for recovering tin and copper, has low ammonia nitrogen and no total nitrogen, and is green and environmentally friendly.