47results about How to "Improve surface mechanical properties" patented technology

The invention discloses high-entropy alloy composite powder and a method for strengthening magnesium alloy through ultrahigh-speed laser cladding. The high-entropy alloy composite powder comprises nickel powder, chromium powder, cobalt powder, iron powder, copper powder, titanium powder, vanadium powder, aluminum powder and ceramic particles, and the mass fraction of the ceramic particles is 10-20% of that of the high-entropy alloy composite powder. The method for strengthening the magnesium alloy through laser cladding comprises the following steps of (1) setting the technological parametersof ultra-high speed laser cladding; (2) loading the high-entropy alloy composite powder on an ultra-high-speed laser cladding machine, so that the energy of a laser beam acts on the powder materials;and (3) feeding the powder materials to the position above the surface of the magnesium alloy to be treated in a synchronous powder feeding mode, melting the high-entropy alloy composite powder into liquid drops which drop into a molten pool on the surface of the magnesium alloy, and forming a cladding layer which is metallurgically combined with the magnesium alloy matrix after solidification. The high-entropy alloy composite powder and the method for strengthening the magnesium alloy through ultrahigh-speed laser cladding avoid over-melting or over-burning of the magnesium alloy, improve thesurface treatment efficiency of the magnesium alloy, and have the advantages of small deformation and high surface smoothness.

The invention discloses a method for improving surface hardness of a TC4 titanium alloy and relates to a method for strengthening the surface of the TC4 titanium alloy by electrical spark, belonging to the technical field of nontraditional machining. Different solid powder materials are added in a near-dry working medium to implement the technology for strengthening the high surface hardness of the TC4 titanium alloy. The method for improving the surface hardness of the TC4 titanium alloy is implemented by the following steps: the TC4 titanium alloy is strengthened by a powder-mixture near-dry electrical spark surface-strengthening method; and the solid powder materials mixed in the working medium respectively are C powder, B4C powder, and a mixture of the C powder and the B4C powder. Experiment parameters in the process of strengthening the surface by powder-mixture near-dry electrical spark are that the pulse interval toff is equal to 150Mus, the pulse width ton is equal to 150Mus, the pulse current ie is equal to 14A, the interelectrode discharge voltage is 120V, the machining depth h is equal to 0.1mm and a tool electrode used is graphite. The technology has the advantages that a strengthened layer and a matrix are combined well, the surface mechanical property is improved remarkably, and the like. The TC4 titanium alloy with the surface being strengthened by the method is up to 1382HV in microhardness, which is increased by 300% compared with that of the original alloy.

The invention relates to a novel spring pre-strengthening finishing composite shot blasting method. The method includes that a spring is subjected to pre-strengthening finishing composite shot blasting by a shot blasting machine, the pre-strengthening finishing composite shot blasting includes three processes, the shot blasting strength is 0.23Amm in the first process, the shot blasting strength is 0.45Amm in the second process, the shot blasting strength is 0.15Amm in the third process, and shot blasting mediums of three-time shot blasting are same to obtain a processed spring product. Compared with shot blasting methods in prior art, the novel spring pre-strengthening finishing composite shot blasting method has the advantages that the beneficial effect of residual compressive stress is increased, and negative influences caused by surface roughness of a part can be avoided to greatest degree.

The invention provides a chromium carbide ceramic thermal-spraying flux-cored wire. The weight percentages of chemical compositions of the flux-cored wire are that 75 to 85 wt% of Cr2C3, 10 to 15 wt% of NiCr, 1 to 3 wt% of La2O3 and 4 to 7 wt% of graphite; and the powder size is minus 120 to plus 80 meshes. The raw materials are put into an agitator to be evenly mixed, a H08 low-carbon steel belt is adopted by a scarfskin, flux-cored wire production equipment is adopted, and the ceramic flux-cored wire of which the outer diameter is F4 to F6 is formed through curliness and extraction. When the flux-cored wire is used, the spraying distance is controlled within a range of 80 to 120mm and the coating thickness is 0.1 to 0.3mm. The flux-cored wire has the advantages that the cost is low, a large bonding strength reaching 15 to 20MPa exists between a sprayed coating and a low-carbon steel substrate, the sprayed coating has higher hardness reaching 600 to 1000HV within a certain spraying distance range and has higher wear resistance.

The invention relates to the technical field of building materials and constructional engineering, in particular to roller compacted concrete and a U-turn road structure prepared from the same. The roller compacted concrete is composed of cement, crushed stone, machine-made sand, a super set-retarding agent, a mortar extractant and water. The U-turn road structure includes a flexible asphalt concrete road structure and a rigid cement concrete road structure. The roller compacted concrete and an asphalt pavement can be simultaneously subjected to mortar extraction and rolling compaction construction. The U-turn road structure can reduce the quality problems such as sedimentation, subsidence, bulging and bleeding of a traditional asphalt concrete pavement under the action of a limit load, the carrying capacity and anti-strain ability of pavements such as U-turn lanes for vehicles, and the cumulative load of braking, parking and other operation of the vehicles are buffered to ensure driving safety.

The invention discloses a solidification contraction-free high-hardness casting magnesium alloy and a process thereof. The alloy comprises the following components in percentage by weight: 0.6-0.8wt.%of Li, 2.0-3.0wt.% of Sb, 5.0-8.0wt.% of In, 4.0-6.0wt.% of Bi, 1.0-2.0wt.% of Pb, 3.0-5.0wt.% of Ge, 1.2-1.5wt.% of Si, 5.0-8.0wt.% of Sn and the balance of magnesium. By adopting the magnesium alloy, casting defects are effectively eliminated, formation of casting pores and looseness is reduced, and excellent mechanical properties of a cast alloy part are achieved. Therefore, the invention provides a lightening solving scheme of a magnesium alloy substitution product, and updating and industry updating requirements of novel materials in China are effectively promoted in the implementation and industrialization process.

The invention belongs to the field of ultraviolet curing ink, and relates to UV gravure white ink for a food packaging BOPP film, and a preparation method thereof. The UV gravure white ink is preparedfrom the following raw materials by weight: 8 to 15 parts of polyether polyol aliphatic polyurethane acrylate, 8 to 15 parts of polyester acrylate, 30 to 40 parts of dipropylene glycol diacrylate, 2to 6 parts of pentaerythritol triacrylate, 1 to 3 parts of 819, 1 to 3 parts of 1173, 0.3 to 0.8 part of Tego-Foamex N, 0.8 to 1.5 parts of DC-57, 0.3 to 0.8 part of Tego-655, 3-8 parts of talcum powder, 3-8 parts of light calcium carbonate, and 15-30 parts of titanium dioxide. The ink is applied to food packaging BOPP films, the printing speed can reach 200 m/min or above while the low cost is guaranteed, and the ink is good in adhesive force and resistant to abrasion and is environment-friendly UV photocuring ink.

The invention discloses a cobalt based metal powder. The metal powder is prepared from, by weight, 13-15% of tungsten carbide, 0.2-0.4% of carbon, 2-4% of calcium fluoride, 2-4% of silicon nitride, 18-23% of chromium, 2-4% of boron, 0.2-0.4% of vanadium, 5-8% of iron, 4-6% of silicon, 9-12% of molybdenum, 1.2-1.6% of manganese, and the balance cobalt. The cobalt based metal powder can be sufficiently fused with a lathe tool base material, the ingredients can be evenly distributed into a cladding layer, ultrahigh hardness ceramic granules are adopted for improving the harness of a lathe tool, in addition, some micro elements are selected for improving the corrosion resistance, strength and heat resistance of the lathe tool, and therefore the cobalt based metal powder is used for performinglaser fusion covering on the lathe tool, and the cost is lowered while the mechanical performance of the surface of the lathe tool can be improved.

The invention provides a method and device for preparing arc figured steel. An aluminum plating layer containing microelements such as rare earth is plated on the surface of the figured steel in an immersion manner, and an interface between the aluminum plating layer and the figured steel is alloyed through heat treatment under a magnetic field; then an obtained figured steel surface is subjected to shot blasting strengthening treatment; and then the figured steel obtained through surface strengthening treatment is directly subjected to cold roll forming, and arc joint steel used in special fields such as tunnel bridges is obtained. By means of the method and device for preparing the arc figured steel, the figured steel surface and immersion plating liquid can be in sufficient contact through electromagnetic stirring, meanwhile, the immersion plating liquid can be evenly distributed to prevent segregation, then the figured steel with the aluminum plating layer is subjected to heat treatment under the magnetic field, and due to the fact that a hot dip coating is formed on the surface and the shot blasting strengthening treatment is conducted, the good-mechanical-performance arc figured steel used in the special fields such as tunnel bridges is obtained. By means of the method and device for preparing the arc figured steel, operation is simple, the cost is low, the yield is high, and the good-mechanical-performance arc figured steel used in the special fields such as tunnel bridges can be continuously prepared. The method and device for preparing the arc figured steel belong to the field of metallurgy technology and material science.

The invention relates to a temperature control assisted ultrasonic rolling surface strengthening device and a temperature control assisted ultrasonic rolling surface strengthening method, belongs to the technical field of metal processing, and solves the problem that the material performance of a processed metal workpiece cannot reach the expectation due to the fact that most existing surface ultrasonic rolling processes are carried out at normal temperature. The surface strengthening device comprises an ultrasonic rolling module and a temperature control module. The temperature control module comprises a cold field loading module and a thermal field loading module; the cold field loading module comprises a liquid nitrogen tank and a liquid nitrogen pipe and is used for cooling a metal workpiece to be treated; the thermal field loading module comprises a heating component, and the heating component is used for heating the metal workpiece; the ultrasonic rolling module comprises a machine tool and a machining tool and is used for achieving ultrasonic rolling machining of the metal workpiece. The surface ultrasonic rolling technology is carried out on the metal workpiece under different temperature conditions, and different material properties are obtained.

The invention belongs to the technical field of mechanical manufacturing, and discloses a preparation method of a magnesium alloy new energy automobile battery box. On the basis of AZ91D and AM60 magnesium alloys, rare earth element gadolinium and a grain refinement inoculant are added for smelting, impurities on the surface of a melt are removed, the melt is refined and subjected to heat preservation, and a battery box die casting is formed through die casting of a battery box die; the battery box die casting is subjected to heat treatment and micro-fox oxidation treatment, the treated battery box die casting is subjected to online flaw detection, and the damaged battery box die casting is separated in time; numerical control punching and tapping are carried out on the battery box die casting through a machining production line; and surface treatment and vacuum ion plating are carried out on the battery box die casting to obtain a battery box finished product. The strength and toughness of the magnesium alloy are improved by adding the rare earth element gadolinium, the alloy is subjected to grain refining by adding the grain refining inoculant, and the plasticity of the magnesium alloy is improved, so that the qualified magnesium alloy is smelted, and subsequent treatment is facilitated by means of manners of surface pre-cleaning and the like.

The invention discloses a fiber oxyfluoridized-graphene composite polyimide powder paint which is prepared from the following raw materials in parts by weight: 2-4 parts of sodium myristate soap, 0.3-1 part of triethanolamine, 100-110 parts of polyimide, 10-14 parts of fluoridized graphite, 0.1-0.3 part of potassium persulfate, 1-2 parts of sodium nitrate, 0.1-0.4 part of potassium permanganate, 4-6 parts of sebacic acid, 0.5-1 part of phosphorus pentoxide, 0.1-0.2 part of dicyclohexylcarbodiimide, 0.1-0.2 part of 4-dimethylaminopyridine, 0.7-2 parts of hydroxyethyl cellulose, 3-4 parts of phosphorylated cotton, 0.5-1 part of calcium naphthenate, 0.8-1 part of saturated octadecacarbamide, 0.6-1 part of 1,2-dimethyl imidazole, 6-8 parts of dibutyl benzene dicarboxylate, 3-4 parts of titanium white, and right amounts of dimethylformamide, anhydrous ethanol and sulfuric acid. The hydroxyethyl cellulose and the like are added to improve the dispersity of the filler in the polymer and enhance the toughness of the finished product.