124results about How to "Good wetting and spreading" patented technology

The invention discloses a method for brazing or fusion-welding through lasers with ultrasonic waves as auxiliaries, which relates to a welding method. The invention solves problems during processes that the lasers are used to braze or fusion-weld coating metals which has low melting points or dissimilar metals, and the problems are that wetting spreading property is bad, filling amount is not enough, stomatas and solders aren't welded fully and the like. The method of the invention is that during the processes that the lasers are used to braze the coating metals which has the low melting points or the lasers are used to fusion-weld the dissimilar metals, simultaneously, the ultrasonic waves with high-frequency vibrations are applied in welding zones which will be coagulated. The invention has the advantages that the occurrences of air holes can be minimized or avoided, and welding cost can be lowered. Welding solders can flow fully due to the high-frequency vibrations, which is beneficial for the wetting spreads of the welding solders and penetrations of the welding solders to the bottom portion of the welding zones, weld pool width and welding filling amount can be increased, the occurrences of welding defects as non-welding fully, undercuts and the like can be avoided, weld formations can be improved, and weld strength can be increased.

A process for preparing cardiovascular stent with a drug coating layer on its surface is disclosed. It includes the steps of: 1. pretreatment for the stent surface by plasma 2. dipping or spraying of the stent surface in routine method by hyperplasia proof drug and coating polymer containing solution The drug coated stent prepared by the present invention can endure long period washing by all kinds of stress and body fluid in the stent transportation and dilation process, with the coating layer not easy to falling off.

The invention relates to a method for brazing a diamond tool through lasers with the assistance of ultrasonic waves. The method includes the steps that firstly, a base body of a grinding wheel is manufactured through a machining method; secondly, the surface of the base body of the grinding wheel is coated with a brazing material; thirdly, diamond grinding particles are cleaned through dilute sulfuric acid, rinsed with deionized water and then dried; fourthly, the diamond grinding particles are subjected to laser surface texturing treatment through laser beams; fifthly, a diamond grinding wheel forming workblank is manufactured; sixthly, the surfaces of the diamond grinding particles are subjected to oil removal treatment and dust removal treatment; seventhly, the grinding wheel forming workblank is heated in a heating furnace, and the temperature is kept; and eighthly, the heated grinding wheel forming workblank is brazed through the lasers with the assistance of the ultrasonic waves, and a brazed single-layer diamond grinding wheel is manufactured. According to the method, release of stress between the diamond grinding particles and the brazing material is facilitated by the adoption of heating and heat preservation, meanwhile, the diamond grinding particles not too closely combined can fall off spontaneously after the high-temperature heat preservation process is conducted, and therefore potential defects generated after welding can be prevented.

The invention provides a magnesium and steel special metal superaudio frequency pulse laser smelting braze-welding wire and a welding method. The welding method comprises the following steps of: forming a beveled edge on a part to be welded of a magnesium alloy and a steel workpiece, and removing oil dirt and an oxidation film from the surface of the workpiece; fixing the magnesium alloy and the steel workpiece on a welding fixture, adjusting the position and the angle of a wire feeding device, automatically feeding the welding wire at a certain angle in front of a laser beam, and protecting a welding seam through argon, wherein the welding wire comprises the following components in percentage by weight: 2 to 10 percent of Al, 0.5 to 5 percent of Zn, 0.1 to 1 percent of Sr, 0.05 to 0.2 percent of B, 0.5 to 2 percent of RE and the balance of Mg; and placing the laser beam on one side of the magnesium alloy workpiece in a slightly deviating way, and heating the welding wire and the magnesium alloy workpiece by using superaudio frequency pulse laser to form a smelting pool, wherein the steel workpiece is kept in a solid state substantially in a welding process and acts with liquid magnesium alloy to form a welding joint. The key and common problem that the improvement of the welding quality of Mg/Fe and Mg/Ti immiscible heterogeneous metal is limited is solved, and the application range of laser smelting braze-welding is expanded.

A medium-temp non-Cd Cu-based soldering wire contains Cu (74.9-82.96 Wt%), Ni (1-5.5), Sn (10-12), P (6-7), Ce (0.02-0.3) and La (0.02-0.3). Its preparing process features that after the electrolytic Cu and Ni in the graphite crucible of MF induction furnace is heated to 600-800 deg.C, the covering agent is added. Its advantages are low smelting temp, narrow smelting zone, better wet spreading performance and certain plasticity.

The invention relates to a silver-free copper based solder and a preparation method thereof, particularly to the silver-free copper based solder for soldering of compressor case covers and copper tubes. The silver-free copper based solder comprises, by weight, 56-68% of Cu, 29-38% of Zn, 0.5-8% of Sn, 0.5-8% of Mn, 0.1-2% of In and other microelements. The preparation method includes fully melting the Cu, the Sn, the Mn, the In and the other microelements to obtain a master alloy; adding Zn into the cooled master alloy with full stirring; taking the alloy out of a furnace; preparing an ingot through pouring; and preparing the ingot into solder wires through extrusion and drawing. The silver-free copper based solder and the preparation method thereof have the advantages that the soldering temperature is 815-865 DEG C and satisfies the process requirement, high silver based solders can be replaced, the cost is low, and the metallographic grain size after welding is low.

The invention discloses a rare-earth plating aid for hot dip tinning and a preparation method thereof. 1 liter of rare-earth plating aid comprises the following raw materials by weight: 80 to 150 grams of inorganic salt, 50 to 100 grams of organic acid, 15 to 25 grams of organic amine salt, 2 to 12 grams of rare-earth compounds and a solvent, wherein the raw materials are mixed, and the solvent is added to 1 liter of constant volume. According to the rare-earth plating aid, the heat stability and the capacity of removing an oxidation film of the plating aid are improved, the corrosivity is reduced, and the capacity of molten tin liquor to the adsorption, moistening and spreading of copper matrixes (copper plating layers) is improved obviously under the modified action of the rare-earth compounds; and a tinning layer of which the thickness is 6 to 9 micrometers can be obtained by one-time dip plating, and powerful guarantee is provided for the weldability and oxidation resistance of products such as electronic leads.

The invention belongs to the technical field of superhard material products, and particularly relates to a brazed superhard abrasive tool and a preparation method thereof. The brazed superhard abrasive tool comprises a substrate and a brazing filler metal layer arranged on the substrate. The brazing filler metal layer comprises a nickel-based brazing filler metal layer close to the substrate, and a copper-based brazing filler metal layer arranged on the surface of the nickel-based brazing filler metal layer. Superhard abrasive grains are embedded in the copper-based brazing filler metal layer. The thickness of the copper-based brazing filler metal layer is smaller than the grain size of the superhard abrasive grains. According to the brazed superhard abrasive tool, the substrate, nickel-based brazing filler metal, copper-based brazing filler metal and superhard abrasive composite structure is formed, the bonding strength between the substrate, the brazing filler metal and the superhard abrasive is improved, and meanwhile the brazing temperature is low, so that thermal damage to the superhard abrasive during brazing is reduced.

The SMT no-lead tinol includes solvent, thixotropic agent, adhesive, composite activating agent, surfactant and antioxidant, and the composite activating agent consists of methyl succinic acid, organic acid and halogen salt. The SMT no-lead tinol has the features of high wettability, good printing performance, homogeneous and fine paste, light color of the soldered residue, low corrosion and high storage stability, and is suitable for use in twice reflux soldering of double-sided circuit board in electronic industry.

The invention discloses butynediol ethoxylate modified bola type organosiloxane and a preparation method thereof. The preparation method includes: butynediol ethoxylate and tetramethyl dihydro disiloxane have reaction under the effects of a platinum catalyst and an amine composite catalyst to obtain butynediol ethoxylate modified tetramethyl disiloxane; balanced copolymerization is performed under the effect of a catalyst to obtain the butynediol ethoxylate modified bola type organosiloxane. The preparation method has the advantages that the method is large in grafted hydrophilic group proportion, high in grafting rate, free of solvent adding and suitable for large-scale industrial production; the prepared hydrophilic group butynediol ethoxylate modified bola type organosiloxane is good in water solubility, good in wetting and spreading ability, high in surface activity and high in defoaming/foam inhibiting performance.

The invention belongs to the technical field of braze soldering flux for electronic packaging and assembly, and discloses a ZnSn-base high-temperature lead-free soft solder and a preparation method thereof. The ZnSn-base high-temperature lead-free soft solder consists of the following components in percentage by weight: 15 to 40 percent of tin, 0.5 to 8 percent of copper, 0.1 to 1 percent of lanthanum and neodymium mixed rare earth, 0.1 to 3 percent of magnesium and/or 0.1 to 2 percent of bismuth and the balance of zinc. The ZnSn-base high-temperature lead-free soft solder has the advantages of no toxicity and no pollution, is high in wetting spreadability and high in tensile strength and mechanical property, and can meet the using requirement of brazing and replace high-lead solders which are applied widely at present or Au-base solders with high price to meet the requirements of the fields of electronic packaging and assembly; and a melting point is between 250 and 450 DEG C.

The invention discloses a Si element contained Ti-based amorphous alloy. The Si element contained Ti-based amorphous alloy is characterized in that the amorphous alloy comprises five components including Ti, Cu, Zr, Ni and Si, and the chemical component is (TiaCubZrcNid)1-eSie, wherein 45at.%<=a<=55at.%, 14at.%<=b<=20at.%, 15at.%<=c<=27at.%, 10at.%<=d<=13at.%, 0at.%<e<=2at.%, and a+b+c+d=100%. According to the Si element contained Ti-based amorphous alloy, the Si element is selected as an alloy component, and the amorphous forming ability of the Ti-Cu-Zr-Ni alloy is improved. In addition, theelements including the Cu and the Ni are added, and therefore the melting point of Ti-based amorphous brazing filler metal can be reduced, the wetting spreadability of the brazing filler metal is better improved, and the Ni and the Zr can improve the stability performance of subcooled liquid and the possibility of amorphous formation.

The invention discloses a method for improving the wetting and spreading performance of a reaction wetting system material. The method comprises the following steps that the surface of a stainless steel base plate is scanned and processed by adopting an ultrafast laser processing technology to obtain a micro-nano stripe texture of which the stripe average width is 1.2-1.4 microns and the stripe average spacing is 1.4-1.6 microns; and the wetting angle of the same brazing filler metal on the scanned and processed stainless steel base plate is 0.9 degrees - 3.3 degrees smaller than the wetting angle of the same brazing filler metal on an unprocessed stainless steel base plate. According to the method, microtexture processing is carried out on the surface of the reaction wetting system material through ultrafast laser, the surface appearance of the reaction wetting system material is changed, the surface roughness is changed, the unique morphology of the micro-nano stripe texture is obtained, and the unique morphology of the micro-nano stripe texture can greatly enhance the capillary action in the brazing filler metal wetting and spreading process, so that the wetting and spreading power of the brazing filler metal on the surface of the reaction wetting system material is improved, the brazing filler metal reacts with the base plate more sufficiently, and the application prospectis great.

The invention relates to brazing fluxes used for welding, in particular to a brazing flux used for melt-brazing of aluminum alloy/stainless steel. The brazing flux is characterized in that the brazing flux is prepared by mixing and grinding powder of potassium tetrafluoroaluminate+potassium hexafluoroaluminate (KAlF4+K3AlF6) eutectic, potassium fluorosilicate, potassium fluoroborate, aluminum, zinc, tin and copper; the brazing flux comprises, by weight, 40%-60% of potassium tetrafluoroaluminate+potassium hexafluoroaluminate (KAlF4+K3AlF6) eutectic, 0-10% of potassium fluorosilicate (K2SiF6), 0-10% of potassium fluoroborate (KBF4), 10%-30% of aluminum (Al), 0-10% of zinc (Zn), 0-10% of tin (Sn), and 0-10% of copper (Cu); the sum of the weight percents of all the raw materials is 100%. According to the brazing flux, the good wetting spreading property of an existing brazing flux is maintained, and meanwhile, the texture of a connector is improved, and forming of brittle intermetallic compounds is reduced, so that the mechanical property of the connector of melt-brazing is improved, and finally dissimilar metal of the aluminum alloy and the stainless steel is connected reliably with high quality. The brazing flux further has the advantages that the melt-brazing process is relatively simple; the energy consumption and the cost of the raw materials are low; the residual quantity of the brazing flux is small after welding; and residues are easy to clean up.

The invention provides silver-based cadmium-free medium-temperature solder and a preparation method thereof and relates to medium-temperature solder and a preparation method thereof. The invention aims to solve the problems of high cost and high melting temperature of silver-based cadmium-free solder produced in the prior art. The silver-based cadmium-free medium-temperature solder is prepared from the following components in part by weight: 49 to 52 parts of silver, 14 to 16 parts of electrolytic copper, 2 to 3 parts of indium, 8 to 12 parts of stannum, 8 to 13 parts of zinc, 1.0 to 2.0 parts of copper phosphorus alloy, 1.0 to 1.5 parts of manganese, 0.2 to 0.7 part of zirconium and 5.05 to 10.8 parts of copper foil wrapped rare earth lanthanum. The preparation method particularly comprises the following steps of: 1, melting and mixing; 2, casting; and 3, extruding. The silver-based cadmium-free medium-temperature solder and the preparation method thereof have the advantages that: 1,the preparation cost is low and the prepared silver-based cadmium-free medium-temperature solder is low in temperature; 2, cadmium is not contained, so damage to a human body and environmental pollution are reduced; and 3, the plastic toughness is high, so a welding wire and a welding ring with the diameter of 0.5 to 2.0 can be prepared. The method is mainly used for preparing the silver-based cadmium-free medium-temperature solder.

The invention provides an epoxy resin composite Sn-Bi lead-free soldering paste. The soldering paste is characterized by comprising the following components of, in percentage by mass, 3%-8% of epoxy resin, a curing agent, an accelerant (the ratio of the epoxy resin to the curing agent to the accelerant is 100:8-30:1-10), and the balance a commercially available Sn-Bi soldering paste. The epoxy resin is a combination of one or any two or three among Npel-127 H type bisphenol A, E44 type bisphenol A, and E51 type bisphenol A in any proportion; the curing agent is a combination of one or any twoor three among m-phenylenediamine, p-phenylenediamine, and dicyandiamide in any proportion; and the accelerant is a combination of one or any two or three of SH-A80, SH-A85, SH-A90, SH-A95, SH-A100, SH-A150 in any proportion. The composite Sn-Bi lead-free soldering paste has good wetting and spreading performances, the shear strength of a soldering head can be remarkably improved, and the soldering paste can be used for reflow soldering of components in the electronic industry.

The invention relates to a serrate double-layer wire mesh corrugated packing which forms a serrate corrugated packing sheet structure by mechanically rolling double-layer wire mesh materials, wherein the top end of the wave crest and the top end of the wave trough of a corrugated packing sheet are respectively formed by connecting smooth arc surfaces, and an arc serrate corrugated structure with a smooth tooth top is formed, and a formed corrugated ridge and the axial direction of the packing form an included angle. Compared with the prior art, the serrate double-layer wire mesh corrugated packing is easy to manufacture, excellent in fluid mechanics and mass transfer performance, especially applicable to separating of small-coefficient mixtures which are difficult to separate, such as separation preparing of isotopes, and capable of being popularized and used in the precise separation field of traditional purification of flavors, fragrances and medical intermediates.

The invention discloses brazing rare earth magnesium alloy brazing filler metal and a preparation method and a brazing process. The brazing rare earth magnesium alloy brazing filler metal comprises the following element components in percentage by weight: 13-19% of Zn, 1.0-3.0% of Ni, 1.8-4.4% of Al, 0.4-1.0% of Ti, 5.1-7.0% of Cu, 0.3-0.8% of Mn, 0.004-0.01% of La, 0.004-0.01% of Nd, and the balance of Mg. The magnesium alloy brazing filler metal reaches the brazing temperature of 420-460 DEG C, and is proper in melting temperature and uniform in components; and a magnesium alloy brazing filler metal foil piece facilitates acceleration of dispersion and interface reaction of all alloy elements in the brazing connecting process, so that the wetting spreadability and the gap filling performance of the brazing filler metal in a rare earth magnesium alloy are improved, the grains are refined, the residual stress is reduced, and the joint bonding strength is improved.

The invention relates to a nickel-based brazing filler metal for an oil cooler quickly brazed in a low vacuum condition. The nickel-based brazing filler metal comprises the following chemical components in percentage by weight: 28.0-30.0% of Cr, 5.0-7.0% of P, 3.5-4.5% of Si, 0.3-0.5% of Mn, 0.1-0.2% of Ti, 2.0-5.0% of Fe, 0-0.2% of sum of impurity elements S, O and N, 0-0.2% of C and the balanceof Ni. By adding ferrochromium powder, resistance to oxidation of an alloy in the low vacuum condition can be improved, so that a blackening problem is solved; by adding titanium and manganese, traceoxygen can be removed in the low vacuum condition, so that the wetting spreadability property of the brazing filler metal on stainless steel is improved. The novel nickel-based paste brazing filler metal has a relatively good flowing property, is moderate in cost, meets the demand on strength, and has good corrosion resistance.