105results about How to "Improve surface corrosion resistance" patented technology

The invention discloses a modification method for improving corrosion resistance and surface functionalization of a biomedical magnesium-based metal material. The modification method for improving corrosion resistance and surface functionalization of the biomedical magnesium-based metal material comprises the following steps: preparing a Tris-buffer solution with a pH value of 7-12, adding a compound which has a certain concentration and is of a phenolic hydroxyl structure or also adding a compound which has a certain concentration and is of a multi-amino structure. The modification method for improving corrosion resistance and surface functionalization of the biomedical magnesium-based metal material is mild in reaction conditions, simple and easy to operate, relatively low in cost and favorable for after-treatment. The magnesium-based metal material prepared by the method and treated with modified coating has relatively excellent corrosion resistance; by virtue of introduction of different components, a plurality of reactive functional groups can be successfully introduced into the prepared material; the prepared material can be used for subsequent fixation of biological molecules (such as heparin, endothelial cell growth factor VEGF, various types of biological function protein and the like) or introduction of biological functions, is capable of exerting the corresponding biological functions and provides a novel research model for application of magnesium and magnesium alloys to cardiovascular materials.

The invention belongs to the technical field of metal surface modification, and in particular relates to a treatment process of a composite surface of an austenitic stainless steel. The process mainly comprises the following steps: 1) washing the surface of a workpiece, and removing the oil stain and impurities on the surface of the workpiece; 2) putting the stainless steel workpiece into an ion nitriding furnace after being cooled down, introducing dried hydrogen, building up of luminance and heating up, after reaching a certain temperature, introducing nitrogen, adjusting the ratio of the nitrogen to the hydrogen and the pressure in the furnace, and subsequently starting to time; and 3) after nitriding for a certain time, stopping introducing the nitrogen, introducing dried air and keeping the temperature for a certain time. Not only is the surface abrasion resistance of the stainless steel treated by using the treatment process improved, but also the excellent corrosion resistance of the stainless steel self is maintained.

The invention discloses a martensite steel 3D free-bending forming device and method and belongs to the technical field of advanced manufacturing and plastic forming. Firstly, based on relative parameters of the forming performance of a pipe material, a corresponding correction factor of the material is obtained through repeated iterative calculation, and an initial model is corrected; after the using situations of parts are tested and calibrated, a three-stage type induction heating device and sensors are matched to achieve precise temperature-control heating; the three-dimensional space of abending mould rotates to extrude the front end of the pipe material to enable the front end of the pipe material to be in a bent shape with the complicated space; and the quenching process is conducted through an annular water-cooling spraying head and accordingly is rapid and uniform. The martensite steel 3D free-bending forming technical problem is solved, and high-temperature free-bending forming under the three-dimensional space is achieved; by means of a rapid quenching system, the strength of 1400 MPa or above is obtained, formation coordinated control of an ultrahigh-strength steel 3Dfree-bending member is achieved; and thus the martensite steel 3D free-bending forming device and method have important engineering application value in the fields of aerospace, rail transportation, automobiles and nuclear power.

A continuous annealing and acid washing method for medium-chromium ultrapure ferrite stainless steel comprises the process flow of cold rolling, annealing heat treatment, acid washing, final water washing, drying, flattening and packaging, and is characterized in that in the acid washing process flow, the acid washing solution is prepared from 120-150g/L of 65% nitric acid, 2-4g/L of 40% hydrofluoric acid and water. According to the invention, in the chemical acid washing stage, reasonable concentration ratio of nitric acid to hydrofluoric acid is adopted and proper acid washing speed is controlled to carry out acid washing on medium-chromium ferrite stainless steel. As a result, on one hand, the performance of a medium-chromium ferrite stainless steel passivation film is obviously improved, and the corrosion resistance of the surface of a medium-chromium ferrite stainless steel 2B board is significantly improved, and on the other hand, the process flow of the existing production factory is not needed to be changed, a special passivation treatment procedure is not needed, and the production cost is significantly lowered.

The invention discloses a chromium-free passivation solution, which has the pH value 1-5 and consists of rare-earth salt, inorganic salt, boric acid, nitric acid and water serving as raw materials. In the chromium-free passivation solution, the content of the rare earth salt is 1-15 g/L, the content of the inorganic salt is 3-30 g/L, the content of the boric acid is 0.1-3 g/L, and the content of the nitric acid is 3-30 ml/L; the rare earth salt is a mixture of vanadate and cerium slat in the weight ratio 1:(1.33-6.5); and the inorganic salt is sodium chloride or potassium chloride. The chromium-free passivation solution has the advantages of good passivation effect, low application cost, high production efficiency, stable performance, difficulty in deteriorating and long storage time.

The invention discloses a magnesium alloy surface gradient laser cladding layer and a preparation technology thereof. The preparation technology includes the steps that a mixture of Al-Si eutectic alloy powder and a binder is coated on the surface of a magnesium alloy base material at first; then a mixture of Ni-Cr-B-Si series nickel-base self-fusing alloy and a binder is coated after drying is completed; and a gradient preset coating can be formed after drying is completed. The gradient preset coating is treated by the adoption of a laser cladding technology, the prepared cladding layer and the base material achieve metallurgical bonding, the Ni-Cr-B-Si series nickel-base self-fusing alloy and the magnesium alloy base material can be well combined together, the effect that the property of the base material is improved can be guaranteed, and meanwhile the impact on the property of the cladding layer due to excessive dilution of the base material can be avoided. The magnesium alloy surface gradient laser cladding layer can be used for surface strengthening and modification of magnesium alloy parts in the industrial field, the application range of magnesium alloy at anti-corrosion places is widened, and the application prospects are broad.

The invention provides waste sagger repairing coating and a use method thereof. The waste sagger repairing coating is prepared from the following raw material components in parts by weight: 30 to 70 parts of fused white corundum powder, 1 to 10 parts of mullite powder, 8 to 30 parts of binding clay, 0 to 5 parts of spodumene, 1 to 5 parts of zirconium oxide, 5 to 25 parts of alpha-Al2O3 micro powder, 1 to 20 parts of magnesium aluminate spinel powder, 2 to 8 parts of sol, 1 to 5 parts of a binding agent, 0.1 to 1 part of a water reducing agent and 16 to 22 parts of water. The using method of the waste sagger repairing coating comprises the steps of preparing the repairing coating, polishing a waste sagger and repairing the waste sagger to obtain a regenerated new sagger. The repaired waste saggar not only can be put into use again, but also is high in strength, high in corrosion resistance and good in thermal shock resistance. The recycling rate of the waste saggars is increased, and the problems of stacking difficulty and environmental pollution are reduced to a great extent.

The invention relates to a method for improving corrosion resistance of the magnesium alloy surface through a short-pulse laser. The method comprises the steps that (1), a magnesium alloy material is subjected to sand papering to remove an oxidation layer and then subjected to acetone cleaning to remove oil; (2), the cleaned magnesium material is placed on a worktable of a nanosecond laser machining system, laser parameters are set, the laser machining system is started, the laser is made to scan on the surface of the magnesium alloy material in a certain speed through galvanometer scanning, and a remelting layer is obtained on the surface of the magnesium alloy material; and (3), the machined metal material is cleaned simply. According to the method for improving corrosion resistance of the magnesium alloy surface through the short-pulse laser, a laser direct writing system is utilized, and by changing the laser parameters such as the frequency, the scanning speed and the power, the fused depth, the area and the like of the metal surface can be controlled precisely; a chemical reagent does not need to be added additionally, so that environment protecting is achieved; arbitrary set of a machining area can be achieved; the machining speed is higher, and the production efficiency is improved; and the short-pulse laser with the low power is used, so that the situation that metal matrix performance remains unchanged is facilitated.

The invention provides a repair process of a screw rod compressor rotor. The repair process comprises the following processing steps of (a) rotor surface pretreatment, (b) laser cladding processing, (c) mechanical processing and (d) rotor detection. The invention discloses the repair process of the screw rod compressor rotor. The repair process has the advantages that the implementation is simple and convenient, the repair cost is low, the screw rod compressor rotor treated by the repair process has higher intensity and better surface corrosion resistance and wear resistance, in addition, the rotor gap is small, and the surface is smooth and cannot be easily contaminated.

The invention discloses low-temperature Ge-containing Sn-Bi solder used for a photovoltaic solder strip. The low-temperature Ge-containing Sn-Bi solder used for the photovoltaic solder strip comprises, by weight, 35%-52% of Bi, 0.025%-0.1% of Ge, and the balance Sn. The invention further discloses a preparation method of the low-temperature Ge-containing Sn-Bi solder used for the photovoltaic solder strip. According to the low-temperature Ge-containing Sn-Bi solder used for the photovoltaic solder strip, by controlling the content of the key element Bi and adding the trace element Ge, grains are refined, and the corrosion resistance of Sn-Bi alloy is improved; and the melting point of the solder is low, and the wettability of the solder is good, so that it is ensured that a copper strip is effectively wetted by the solder, and traditional Sn-Pb solder can be replaced by the low-temperature Ge-containing Sn-Bi solder.

The invention discloses corrosion-resistant low-temperature solder for a photovoltaic solder strip and a preparation method of the corrosion-resistant low-temperature solder. The solder comprises, by weight, 55%-60% of Bi, 0-0.01% of Sb, 0-0.0005% of Al, 0-0.0005% of Zn and the balance tin. The method comprises the following steps that a proper amount of the tin and bismuth is heated to 280 DEG C to 300 DEG C, and mixed melt is obtained; a proper amount of bismuth chloride is added to cover the surface of the mixed melt, then heat preservation is carried out, temperature is reduced to below 180 DEG C after stirring of 15-20 minutes, and molten solder is obtained; and finally the molten solder is filtered through porous carbon, the filtered molten solder is cast, and the corrosion-resistant low-temperature solder is obtained. According to the solder, the content of the key component Bi is controlled, it is measured that the melting point is close to 139 DEG C, the temperature difference of a solid phase and a liquid phase is only about 12 DEG C, and the phenomenon of segregation can be effectively avoided in dip soldering and other welding processes with the high cooling rate; the content of impurities is controlled to be low, so that the melting point of the prepared solder is low, and the corrosion resistance of the prepared solder is high.

The invention discloses a method for improving corrosion resistance of the surface of magnesium alloy on the basis of micro-arc oxidation and laser remelting. Firstly, after micro-arc oxidation treatment is conducted on the surface of the magnesium alloy, a layer of ceramic film is obtained, the film layer is prefilled with a thin layer of graphene oxide particles through ultrasonic oscillating, then microcracks and holes of the ceramic film are filled with molten graphene oxide particles effectively through laser remelting technology, and thus corrosion resistance of the surface of the magnesium alloy is improved greatly. The method is environmentally friendly in process and high in repeatability, and a novel way is developed for improving the corrosion resistance of the surface of the magnesium alloy.

The invention discloses a preparation method of a hollow slab beam for a bridge. A basalt fiber reinforcement cage replaces a reinforcement cage and serves as a framework of the hollow slab beam, the problem of reinforcement corrosion is solved, and the mechanical property, the physical property and high-temperature stability of the hollow slab beam are improved. Basalt fiber reinforcements are connected into a stereoscopic basalt fiber reinforcement cage framework by a basalt fiber connecting ring, basalt fiber connectors do not deform or collapse and are simple in structure, convenient and rapid, binding or welding is omitted, connectors made of second materials are not led in, practicability of the basalt fiber reinforcement cage is improved, the service performance of the hollow slab beam is improved, and the service life of the hollow slab beam is prolonged.

The invention discloses a low-wear abrasive capable of improving corrosion resistance capability of the stainless steel surface and a preparation method of the low-wear abrasive and belongs to the technical field of grinding and polishing finish machining for stainless steel surface machining. The low-wear abrasive capable of improving the corrosion resistance capability of the stainless steel surface forms a quasicrystal and approximates and comprises components as follows: Al-(Li,Cu,Fe,Co,Cr,V,Mn,Ru,Re,Os), TiZrNi, (Zn/Cd)-Mg-(Y,Yb,Gd,Tb,Dy,Ho,Er,Sc) and Cd-(Ca,Y,Gd,Tb,Tm,Ho,Dy,Er,Yb), and the content of the quasicrystal and the approximates is larger than 50%. The abrasive is used for grinding and polishing the stainless steel surface and also can realize low-wear polishing and finish machining of stainless steel and rapidly improve the surface corrosion resistance capability.

The invention discloses an aluminum oxide modified gradient laser cladding layer and a preparation method thereof. Magnesium alloy serves as base material, Al-Si alloy powder serves as a first precoated layer, the mixed powder of nickel-based self-melting alloy powder and Al2O3 serves as a second precoated layer, and the aluminum oxide modified gradient laser cladding layer is formed through laser cladding. The corrosion potential of the Al2O3 modified gradient laser cladding layer is about -1.1 V and is similar to that of a Ni35, Al-Si/Ni35 cladding layer, the corrosion current density is large in difference and is about 1/15-1/2 that of the base material, and a good corrosion resistant effect is achieved. The aluminum oxide modified gradient laser cladding layer and the preparation method thereof can be used for surface strengthening and modification of magnesium alloy parts in the industrial field, the application range of magnesium alloy in corrosion resistant occasions is extended, and wide application prospects are achieved.

The invention provides a rare earth permanent magnet with a multilayer composite electroplated coating and a composite electroplating method thereof. The rare earth permanent magnet includes a rare earth permanent magnet body, a first layer of nickel coating, a second layer of copper coating, a third layer of nickel coating and a fourth layer. An electroplating solution includes: 40-60g/L stannous pyrophosphate, 30-45g/L nickel chloride, 250-320g/L potassium pyrophosphate, and 20g/L glycine. The composite electroplated coating not only can play an anti-corrosion role of conventional electroplated nickel, but also has certain protection effect on the eyes of inspectors, and the uniform appearance and black and shiny color can reach certain decorative effect.

The invention discloses a low-carbon nickel-chromium-molybdenum-niobium alloy stainless-steel seamless pipe. The stainless-steel seamless pipe contains the following ingredients in percentage by weight: 58% of nickel, 20%-23% of chromium, 8%-10% of molybdenum, 3.15%-4.15% of niobium, 5% of iron, 0.4 of aluminum, 0.4 of titanium, 0.1% of carbon, 0.5% of manganese, 0.5% of silicon, 1% of cobalt, 0.015% of phosphorus and 0.015% of sulfur. The stainless-steel seamless pipe is produced by the steps of: (1) drilling a hole in the center of a blank and inspecting the blank; (2) heat-treating the blank after hole drilling; (3) acid-washing the blank after heat treatment; (4) coping, lubricating, cold drawing and rolling, and deoiling the acid-washed blank; (5) judging whether a finished product requirement is met, if so, implementing solid solution heat treatment, straightening, stationary cutting and acid washing on a finished product; (6) if not, implementing solid solution heat treatment, straightening, stationary cutting and acid washing on an intermediate product, and repeating the step (4); and (7) inspecting the finished product, spraying words, packaging and weighing the finished product, and delivering the finished product out from a warehouse. According to the stainless-steel seamless pipe, the corrosion resisting performance of the surface is enhanced, the performance standard is optimized, the manufacturing cost is lowered and the production process is simple.

The invention discloses a preparation method of high-strength Si3N4/SiC composite ceramics; and the preparation method comprises the following steps of: (a) using SiC powder as a main material; adding 10-15 % of Si powder, 2.2-2.7 % of Al2O3, 0.6-0.8 % of Fe2O3, 2.5-3.0 % of Y2O3 and 0.5-1.2 % of CeO2 to the main material; (b) wetly rolling a mixed powder obtained in the step (a) in a ball mill for 4-6 h; drying and granulating the mixed powder; and dryly pressing the mixed powder for molding; and (c) nitriding and sintering the mixed powder at 1500-1600 DEG C so as to obtain the Si3N4/SiC composite ceramics. The Vickers hardness of the composite ceramic material prepared by the method disclosed by the invention can reach 2.185 GPa, the heat bending strength of the composite ceramic material can reach 420 MPa, and the breaking tenacity of the composite ceramic material reaches 12 MPa*m1/2; and the corrosion resistance of the surface of the composite ceramic material is enhanced.

The invention provides ultra-high-speed laser cladding iron-based metal powder, and a preparation method and application thereof. The iron-based metal powder comprises the following chemical components of, in percentage by mass, 0.6 %-1.0% of C, 17.0 %-20.0 % of Cr, 5.0 %-6.5 % of Ni, 2.0 %-4.0 % of Mn, 1.0 %-1.5 % of Mo, 4.0 %-6.0 % of Ti, 1.0 %-1.5 % of B, 0.08 %-0.15 % of N, less than or equalto 0.5% of Si, less than or equal to 0.030% of P, less than or equal to 0.030% of S and the balance Fe and inevitable impurities. According to the metal powder, the particle size is 15-65 microns andthe fluidity is 16-20 s/50g. The invention further provides the application method of the metal powder. According to the application method, by adopting an super-high-speed laser cladding technology,and matching different processes, a shaft part base body surface is strengthened and repaired.