218 results about "Crack free" patented technology

The invention provides a method for additive manufacturing of a large-size crack-free titanium-aluminum alloy, and relates to the technical field of additive manufacturing of titanium-aluminum alloy composite materials. The method comprises the steps of setting of a medium-frequency induction heating device, deposition, rapid remelting, in-situ remelting and in-situ heat treatment. According to the method disclosed by the invention, the density of a deposited layer and the integrity of a workpiece are creatively and synergistically improved through an induction heating technology, high-speed remelting scanning of each layer of double laser beams, in-situ remelting and in-situ heat treatment, and the fatigue property, the mechanical property and other properties of the prepared large-size titanium-aluminum alloy are improved; the occurrence probability of thermal stress cracks is greatly reduced; the method is high in resource utilization rate, low in production cost, short in process, easy to operate, high in efficiency, uniform in component distribution of each deposition layer and beneficial to industrial large-scale production and popularization.

Aimed at the cracking problem of nickel-based superalloys for additive manufacturing, the present invention provides a nickel-based superalloy with low cracking sensitivity for additive manufacturing. The microstructure is adjusted and controlled by means of rare-earth microalloying, thereby facilitating the formation of high-density stacking faults, a rare-earth-containing nano second phase, and refined crystal grains and a subcrystal structure in the alloy matrix, increasing the number of isometric crystals, reducing the columnar crystal proportion and the length-to-diameter ratio thereof, decreasing the cracking sensitivity, and greatly improving the strength and plasticity. The method solves the problem of cracking in an additive manufacturing, storage and heat treatment of a nickel-based superalloy, and can be used to prepare a high-performance and crack-free nickel-based superalloy. The present invention has a rational composition design and a simple preparation process, results in a product having excellent performance, and facilitates large-scale industrial production and practical application.

The invention discloses a high-temperature wear-resistant crack-free high-entropy alloy and a preparation method and application thereof, the molecular formula of the alloy is as follows: Fe < 11.9 > Co < 23.8 > Cr < 23.8 > Ni < 35.7 > Nb < 4.8 >, and a Laves phase exists in the microstructure of the alloy. The preparation method comprises the following steps: putting weighed powder into a ball milling tank for ball milling, uniformly mixing the powder, and then drying, sieving and drying for storage; 304L stainless steel is selected as a base material, a sand mill is used for polishing the surface of the base material so as to remove surface oxide skin until a bright surface is exposed, and oil stains on the surface are cleaned; and the dried powder is placed in a powder feeding tank in a laser system, high-purity Ar gas is used for feeding the powder to a round spot laser head for melting and stacking, and the high-temperature wear-resistant crack-free high-entropy alloy without cracks is formed through layer-by-layer continuous deposition. By adding the Nb element, a Laves phase capable of improving the high-temperature performance is formed in a matrix, a high-entropy alloy sample is prepared through the laser directional energy deposition technology, subsequent heat treatment does not need to be conducted on the high-entropy alloy sample, and the deposited alloy has the excellent wear resistance at the high temperature.

The invention discloses a crack-free laser powder bed additive manufacturing method for gamma'reinforced nickel-based alloy, which comprises the following steps: firstly, preparing raw material alloy powder, and detecting the total content of Al and Ti elements in the alloy powder; then the powder is loaded into a forming bin, a layer of powder is quantitatively laid every time, a powder bed is scanned through laser, laser energy input and the scanning speed are controlled, the powder bed is rapidly melted and solidified, a layer of solid is formed, the layer height of the solid is 0.02-0.05 mm, and the higher the total content of Al and Ti elements in the alloy powder is, the smaller the layer height is; and after a layer of entity is formed, the forming substrate is controlled to descend by the height of a construction layer, a layer of powder is laid again, laser scanning is conducted again, and the steps are repeated till construction is completed. According to the method, a cooperative control strategy of thin-layer thermal control is adopted, nucleation and expansion of cracks are restrained by controlling the descending height of a formed substrate and controlling laser parameters, and the crack-free laser additive meeting the requirements is manufactured.

The invention discloses a high-wear-resistance additive forming titanium-based composite material and a preparation method thereof. The high-abrasion-resistance additive forming titanium-based composite material is mainly composed of a base body and an amorphous ceramic film, and the high-abrasion-resistance additive forming titanium-based composite material is prepared from, by mass, 97.0%-99.8% of the base body and 0.2%-3% of the amorphous ceramic film. By accurately controlling the thickness and the quality of the amorphous ceramic film, the number and the size of the reinforced phases can be regulated and controlled, and the fluidity and the oxidation resistance of the additive manufacturing titanium alloy powder can be remarkably improved through introduction of the amorphous ceramic film; the in-situ synthesis ceramic reinforced titanium-based composite material prepared through additive manufacturing is free of cracks, high in hardness, good in wear resistance and suitable for being used under harsh working conditions.

The invention discloses a method for obtaining a high-mechanical-property high-entropy alloy laser powder bed melting forming component, which comprises the following steps of: printing a three-dimensional solid component by using mixed powder of a high-entropy alloy and ceramic particles as a raw material and adopting a powder-based laser powder bed melting process; and the high-entropy alloy component which is high in compactness, free of cracks, fine in grain and excellent in mechanical property can be obtained. According to the obtained high-entropy alloy laser powder bed melting forming component, multiple kinds of strengthening such as grain refinement and tissue structure transformation occur in the laser powder bed melting process, and compared with a high-entropy alloy original material, the high-entropy alloy laser powder bed melting forming component has better mechanical performance. The obtained high-entropy alloy laser powder bed melt forming component can be applied to the fields of aerospace engine part manufacturing, anti-corrosion coatings and the like, and the requirement for the high-strength high-entropy alloy component is met.

The invention discloses a corrosion-resistant and wear-resistant composite metal plate, which relates to the technical field of composite metal materials, and is technically characterized by comprising the following steps: firstly, preparing a flux-cored wire, and preparing deposited metal components according to mass percent by using a specific low-carbon steel strip; then, a thick low-carbon steel plate or a low-alloy steel plate serves as a base plate, a double-layer structure is formed through a gradient surfacing technology, a transition layer is prepared according to the proportion, a main wear-resisting layer is formed by fusing and diffusing flux-cored wires and contains various high-hardness wear-resisting phases, the lap joint width is controlled, cooling is conducted, and a surfacing composite layer is formed; the surfacing composite layer is integrally leveled through a press machine, and a semi-finished product is obtained; and finally, mixing organic silicon modified polyester resin and the like to prepare a joint sealing agent, coating the semi-finished product for 3-4 layers, and curing to obtain a finished product. The wear-resistant layer is free of cracks, and the corrosion resistance of the base body is improved.

The invention relates to the technical field of building materials, and discloses a self-repairing microcapsule-based composite waterproof material and a preparation method thereof, and the self-repairing microcapsule-based composite waterproof material comprises the following components by weight: 60-80 parts of modified organic silicon resin, 5-15 parts of nano clay (modified montmorillonite), 3-8 parts of a self-repairing microcapsule, 2-5 parts of a water-based cross-linking agent, and 0.5-2 parts of a dispersing aid. Stress generated by settlement and temperature change of a building structure can be effectively resisted, and cracks are reduced fundamentally; meanwhile, the material still keeps flexibility at the low temperature of-30 DEG C (without cracks when bent), and the technical bottleneck that a traditional material is prone to embrittlement in a cold region is broken through; more importantly, the 24-hour self-repairing rate is up to 92%, self-healing of cracks can be achieved without manual intervention, the service life of waterproof engineering is prolonged to more than two times that of a traditional material, the full-life-cycle maintenance cost is remarkably reduced, and a long-acting and reliable solution is provided for the field of building waterproofing.

The present invention relates to a method for manufacturing a part (1) with improved resistance to oxidation and high-temperature corrosion, comprising at least the deposition of a non-cracked crystalline β-Yb2Si2O7 environmental barrier layer (7) on an at least partially ceramic matrix composite material (3), wherein the environmental barrier layer is deposited by chemical vapour deposition from a gas phase comprising a precursor mixture of (a) a compound A of formula SiClxHy, in which x is an integer from 1 to 4 and y is an integer from 0 to 3, with x + y = 4, and (b) elementary ytterbium or ytterbium(III) chloride, and wherein, during deposition, a temperature between 1100°C and 1300°C and a pressure of 150 mbar or less are imposed.

The invention discloses cobalt-based alloy powder and application thereof, and belongs to the technical field of metal alloy materials. The cobalt-based alloy powder comprises the following components in percentage by mass: 0.2 to 0.6 percent of C, 2.0 to 3.0 percent of Si, 2.0 to 3.0 percent of Fe, 25.0 to 32.0 percent of Cr, 5.0 to 7.0 percent of Mo, 1.0 to 3.0 percent of Mn, 0.1 to 9.0 percent of W, 2.0 to 12.0 percent of Ni and the balance of Co and inevitable impurities. The cobalt-based alloy powder provided by the invention can be used for repairing a nut column through laser cladding, a cladding layer without cracks, air holes, inclusions and other defects on the surface and the interior can be obtained after cladding under certain laser power, the average Vickers hardness of the cladding layer can reach 434.3 Hv, meanwhile, the cobalt-based alloy powder has excellent wear resistance, and the service life of the cladding layer is prolonged. The method has remarkable advantages in the aspect of improving the material surface performance, and is suitable for various repair scenes needing high hardness and wear resistance.

A SiC carrier wafer has a diameter of at least 7.5 cm and a height between 200 μm and 500 μm. The wafer includes an inner section and an outer section. The outer section surrounds the inner section and the inner section includes a part of a SiC growth substrate. The inner section is formed by a crystal structure that is predominantly formed by a 3C crystal structure. The outer section is formed by a crystal structure predominantly formed by a 3C crystal structure and includes crystallites extending in length direction of the individual crystallite of more than 5 μm. A bow of the wafer is less than 50 μm and a warp of the wafer is less than 50 μm. The crystal structure of the inner section and the crystal structure of the outer section are Nitrogen doped and have an electric resistivity less than 0.03 Ohm-cm.

The invention discloses a method for inhibiting cracks in additive manufacturing of a high-O-phase-content Ti2AlNb alloy. The method comprises the following steps that firstly, supplied materials are detected; 2, slicing the model; 3, preheating the substrate; 4, prefabricating a bottom layer; and 5, alloy preparation is conducted, and the crack-free high-O-phase-content Ti2AlNb alloy component is obtained. By preheating the substrate and the powder layer for multiple times and matching with the powder melting process, powder melting solidification and metallurgical bonding can be remarkably improved, the temperature gradient in the forming process can be effectively regulated and controlled, assistance of other equipment is not needed, thermal stress can be remarkably relieved, and the inhibition effect on generation of cracks in the alloy is achieved; the high-O-phase-content Ti2AlNb alloy component without internal cracks is prepared, the technical problems that the high-O-phase-content Ti2AlNb alloy is poor in additive manufacturing forming quality and the internal crack inhibition process is complex are effectively solved, and the method has wide application prospects in the fields of advanced aviation and weaponry.

The invention discloses ceramic particle reinforced medium-entropy alloy powder with large density difference as well as a preparation method and application thereof. The composite powder consists of 3-5wt% of B4C powder and the balance of CoCrNi alloy powder. The average particle size of the B4C powder is less than 0.5 mu m, and the average particle size of the CoCrNi alloy powder is 80-150 mu m; b4C powder and CoCrNi alloy powder are mixed through an acoustic resonance mixing technology, and the surface of the CoCrNi alloy powder is coated with nanometer B4C powder. According to the method, the surface of CoCrNi alloy powder is evenly coated with small-particle-size B4C powder through the acoustic resonance mixing technology to prepare the CoCrNi-B4C composite powder, the optimal balance of strength and toughness is achieved, uniform powder feeding cladding is achieved, the surface of a to-be-cladded plate is cladded with the composite powder subsequently through rectangular light spot laser equipment, and therefore the composite powder is obtained. The large-area crack-free laser cladding high-hardness CoCrNi-B4C composite coating is obtained, the cladding efficiency is greatly improved, and the hardness of the coating exceeds 400 HV.

The application provides a preparation method of laser additive manufacturing crack-free Ni3Al-based high-temperature alloy, comprising the following steps: (1) uniformly mixing micron-sized Ni3Al-based high-temperature alloy powder and nano Hf ceramic particles, so that the nano Hf ceramic particles are uniformly wrapped on the surface of the micron-sized Ni3Al-based high-temperature alloy powder, to obtain a composite powder; (2) drying the composite powder; (3) layer-by-layer melt forming the composite powder by using a laser directional deposition device, to obtain the laser additive manufacturing crack-free Ni3Al-based high-temperature alloy. The application also provides the laser additive manufacturing crack-free Ni3Al-based high-temperature alloy prepared by the method. The preparation method of the laser additive manufacturing crack-free Ni3Al-based high-temperature alloy can prepare the crack-free Ni3Al-based high-temperature alloy by the laser additive manufacturing method, and is simple in preparation and low in cost.

This invention provides a high-hardness, crack-free flux-cored welding wire and its preparation method. The flux-cored welding wire includes an outer sheath and a flux core. By weight, the flux core comprises the following components: boron carbide 5.6-8.6 parts; 75% ferrosilicon 3.1-4.6 parts; electrolytic manganese 0.6-1.6 parts; 80% ferrovanadium 0.3-1.2 parts; nickel powder 0.3-1.0 parts; 68% high-carbon ferrochrome 67.5-94.5 parts; and iron powder 6-6.5 parts. The preparation method of the flux-cored welding wire is as follows: [The following components are listed:] boron carbide, 75% ferrosilicon, electrolytic manganese, 80% ferrovanadium... Ferrovanadium, nickel powder, 68% high-carbon ferrochrome, and iron powder are added sequentially to a dryer and dried for 2-3 hours. The mixture is then thoroughly mixed using a three-dimensional motion mixer and placed in an insulated box for later use. The outer sheath is placed on a forming machine, which rolls the outer steel strip into a U-shaped groove. Flux-cored powder is added to the U-shaped groove, and the forming machine closes and pulls the groove to obtain the flux-cored welding wire. The flux-cored welding wire of this invention features high hardness, no cracks, high temperature resistance, and corrosion resistance. Furthermore, the low production cost of the flux-cored welding wire facilitates industrial production.

The invention relates to a nuclear power plant main pipeline damage tolerance establishment method. The method comprises the following steps: S1, determining the critical crack size of the main pipeline of the nuclear power plant at the end of the life; and S2, performing finite element calculation based on the established finite element model of the crack-free structure of the main pipeline so as to obtain stress distribution of the crack-free structure under each load working condition. S3, according to the initial crack size and the finite element calculation result, stress intensity factor calculation, transient pairing, elastic-plastic correction and fatigue crack propagation calculation are conducted in sequence, and the life end crack size of the main pipeline is obtained. And S4, when it is judged that the life end crack size of the main pipeline is smaller than the critical crack size, the step S3 is executed again to conduct iterative calculation on the initial crack size. And when the final crack size of the service life of the main pipeline is judged to be greater than the critical crack size, taking the initial crack size updated by the last iteration as the structural damage tolerance. The nuclear power pipeline defect evaluation period can be shortened, and the evaluation efficiency is improved.

The invention relates to the technical field of semiconductor manufacturing, in particular to a high-yield and crack-free temporary bonding method for laser lift-off of a Mini / MicroLED COW whole-surface chip structure. According to the method, a composite membrane material composed of double-sided acrylic UV viscosity-reducing glue and a PET rigid base material is adopted. And high pressure is applied in a vacuum environment to complete bonding of the temporary substrate and the COW, so that large-area and high-density embedding of the acrylic acid adhesive layer and the surface structure of the chip is realized. And carrying out UV exposure to promote the phase change of the acrylic adhesive layer, and curing the acrylic adhesive layer from an initial soft viscoelastic state to a high-modulus hard acrylic support structure. The hard supporting surface and the vacuum embedded structure act together, so that excellent internal stress resistance is provided, and cracks in laser lift-off and subsequent processes are effectively prevented. Meanwhile, after the cured structure is subjected to subsequent permanent bonding, the visbreaking layer can be activated through simple UV irradiation, and residue-free and easy-to-separate de-bonding of the temporary substrate and the PET film material is realized.

The application relates to a preparation method of an aluminum-based composite material plate. After sintering and forging, an aluminum-based composite material powder blank with a length-width ratio of 1.5-2 and a thickness of 70mm-110mm is pressed three times to prepare an aluminum-based composite material plate with a length-width ratio of 9-12 and a thickness of 10mm-35mm. The sintered blank is densified under small deformation through the first pressing, the sintered blank which has been densified is deformed in a large size under low pressure through the second pressing, the sintered blank is filled under low pressure through the third pressing, near-net-shape forming is realized, and thus the aluminum-based composite material plate without circumferential cracks and with consistent internal density is obtained.

The application discloses a method for eliminating thermal cracks in nickel-based alloy additive repair, which comprises the following steps: firstly, quantitatively analyzing elements contained in the nickel-based alloy, and simulating a solidification curve based on thermodynamics according to the elements; secondly, obtaining a CSI-fs curve based on the solidification curve; thirdly, designing a heat treatment system through thermodynamic simulation, and performing composition homogenization treatment on the nickel-based alloy; and finally, performing electron beam additive repair. Results show that the nickel-based alloy treated by the method does not produce cracks during the additive repair, i.e., the thermal cracks are eliminated, the connection is stable, and the crack-free additive repair is successfully realized.

This invention discloses a rapid generation method for rectangular disks suitable for structured meshes. This method simplifies crack propagation calculations of the disk into a parametric fracture mechanics model, enabling the calculation of stress intensity factor and crack propagation life. Specifically, finite element modeling is employed to extract the geometric boundaries of the disk and its partitions, considering the influence of geometric dimensions and boundary effects on crack propagation. Based on coordinate system transformation, using the crack initiation point and stress gradient direction as a reference, the rectangular plate can be accurately located, improving modeling efficiency. This invention simplifies the crack propagation plane into a finite-size rectangular plate. Based on boundary intersection point capture, it achieves high-fidelity equivalence between the rectangular plate model and the actual complex contour of the disk, reducing calculation errors in the boundary region using traditional methods. Furthermore, by extracting the crack-free stress distribution along the crack propagation direction on the rectangular plate, the stress intensity factor at the crack tip and crack propagation life can be calculated using the weighted function method.

The invention relates to the technical field of high-temperature-resistant coatings, in particular to a geopolymer-based reversible color-changing high-temperature-resistant material as well as preparation and application thereof. The geopolymer-based reversible color-changing high-temperature-resistant material provided by the invention comprises the following components in parts by weight: 60 parts of metakaolin, 60 parts of an alkali activator, 30-150 parts of BiVO4 and 30 parts of water, the invention aims to provide an environment-friendly high-temperature-resistant inorganic reversible thermochromic coating by taking a geopolymer as a base material and taking BiVO4 as a pigment filler. A coating further prepared from the geopolymer-based reversible color-changing high-temperature-resistant material provided by the invention is crack-free, has excellent water resistance and wear resistance, is environment-friendly and non-toxic, does not decompose at high temperature, and has excellent reversible thermochromic property.

The application belongs to the technical field of metal-organic framework material and gas separation membrane preparation, and particularly relates to a preparation method of a halogen-modified high-porosity self-supporting MOF glass membrane, which comprises the following steps: firstly, a high-porosity vitrifiable MOF material with imidazole as a first ligand and a series of halogen benzimidazoles as second ligands is synthesized by a low-temperature solvothermal method; then, halogen MOF powder with high-temperature melting characteristics is pressed into a dense and crack-free disc-shaped precursor by a mechanical cold-pressing method; and finally, the disc-shaped precursor is subjected to high-temperature melting heat treatment under an inert atmosphere, and the heating temperature can ensure that the MOF particles are fully melted and flow, so that the interstitial gaps, defects and grain boundaries among the original particles in the thin sheet are completely eliminated. The application aims to prepare a defect-free, high-selectivity and high-flux MOF glass membrane, and solves the problems of low porosity and limited gas separation performance of the existing MOF glass membrane.

This invention discloses a method for preparing high-elongation bars for cold forging, belonging to the field of aluminum alloy preparation technology. Through optimization of composition and process, the prepared bars possess high purity, uniform and fine equiaxed grain structure, and excellent plasticity, with significantly improved elongation. This meets the stringent requirements of cold forging for high material plasticity, resulting in a bright, crack-free surface and uniform grains after cold forging, overcoming problems such as oxide scale, coarse grains, and poor dimensional accuracy caused by hot forging. Furthermore, the introduction of modified talc and sodium nitrate as refining agents further promotes uniform microstructure, achieving high elongation and excellent cold forging performance.

The invention relates to a ceramic bottle crack detection method based on machine learning open set recognition, which comprises the following steps: detecting the passing of a ceramic bottle on a conveyor belt through a photoelectric sensor, and when the passing is detected, controlling a knocking hammer to knock the bottle and collecting a sound signal through a microphone; intercepting, filtering and preprocessing the sound signal, and extracting a plurality of features; performing crack open set identification in two steps, adopting an improved MFCC to train a dichotomous support vector machine to detect whether a bottle has a crack or not, respectively training five single-class support vector machines by using all features to serve as a basic model of a first layer of a stacking model, and adopting a local outlier factor as a meta-model of a second layer of the stacking model to identify the crack open set of the bottle; the stacking model is used for detecting whether abnormal noise exists or not; and 4, according to an open set identification result, if abnormal noise exists during detection, re-detection is carried out, and otherwise, the ceramic bottles with cracks are removed according to a binary classification result. The open set recognition method is adopted to remove the influence of abnormal noise on the detection result, and the detection precision is high.

The invention provides a preparation method of a multi-field coupling laser cladding FeCoCrNiMo high-entropy alloy coating, and aims to solve the problems of chloride ion corrosion and cavitation corrosion of marine propellers and rudder shafts in a marine environment. The preparation method comprises the steps of base material pretreatment, composite powder preparation, multi-field coupling laser cladding, post-treatment and the like. According to the method, a certain proportion of the composite slag former (CaO-Al2O3-MgO-CaF2-Y2O3) is added into the FeCoCrNiMo high-entropy alloy powder, and in the laser cladding process, an ultrasonic field and / or a magnetic field are / is adopted for assistance, so that the uniformity, compactness and corrosion resistance of the high-entropy alloy coating are remarkably improved. The prepared FeCoCrNiMo high-entropy alloy coating is good in bonding performance with a base material, has no defects such as cracks and holes, has excellent chloride ion corrosion resistance and cavitation corrosion resistance, and can meet the high protection requirement in the marine environment.

The application provides a three-step forming cold extrusion process method and a forming die for a firing pin, which comprises the following steps: pre-cutting, pre-cutting two adjacent part material sheets apart by using a pre-cutting punch and a pre-cutting die; pre-forming, pressing the required material of the part into a material storage hole by using a pre-forming punch and a pre-forming die, and extruding the excess material into the extrusion area of the next working step; rough forming, rough forming of the part is completed by using a rough forming punch and a rough forming die; trimming the excess material, the material extruded in the pre-forming and rough forming steps is cut off by using a trimming punch and a trimming die, so that the edge of the material is ensured to be free of cracks; fine forming, fine forming of the steel strip is performed by using a fine forming punch and a fine forming die. The three-step forming cold extrusion process method breaks through the bottleneck in the cold extrusion forming process of small high-strength, high-precision and special-shaped metal parts, significantly improves the forming efficiency and improves the forming quality. The forming quality of the firing pin obtained by the forming die is high.

The present invention relates to a process for producing a steel alloy part, which includes providing a steel alloy powder mixture containing SiC, forming the part from the powder mixture using an additive manufacturing technique, and subjecting the formed part to a thermal treatment for a duration of 1 to 150 minutes at a temperature ranging from 600°C to 750°C. This process is particularly suitable for creating parts with enhanced properties, such as cutting tools, bearings, punches, and gears, which can be crack-free and defect-free. The additive manufacturing technique is Laser Powder Bed Fusion. The steel alloy powder mixture composition and preparation method are also detailed, along with the characteristics of the resulting steel alloy part, which comprises a bainitic ferrite matrix with graphite particles and carbides distributed therein.

The invention discloses a metallurgical-defect-free high-temperature wear-resistant cobalt-based alloy coating and a preparation method and application thereof.The preparation method comprises the following steps that (1) Fe powder, Co powder, Cr powder, Ti powder, Mo powder and Ni powder are accurately weighed according to the stoichiometric equation Co57Fe5Ni5Cr25Ti5Mo3, and (2) the weighed powder is put into a ball milling tank to be subjected to ball milling, so that the powder is evenly mixed, and then drying, sieving and drying storage are conducted; (3) 5NiCrMo hot work die steel is selected as a base material, a sand mill is used for polishing the surface of the base material so as to remove surface oxide skin until a bright surface is exposed, and oil stains on the surface are removed; and (4) a laser directional energy deposition method in laser additive manufacturing is used for continuously depositing the crack-free cobalt-based alloy coating with high temperature resistance, wear resistance and no cracks one by one. The high-temperature wear-resistant alloy shows excellent wear resistance at a high temperature, the alloy has a shallower wear depth and a narrower grinding crack width at the high temperature, and the wear rate at the high temperature of 800 DEG C is reduced from 2.171 * 10 <-4 > mm < 3 > / N.m of a 5CrNiMo base material to 2.45 * 10 < 6 > mm < 3 > / N.m of a coating.

The invention discloses a super duplex stainless steel S32750 medium plate and a hot rolling method thereof.The medium plate comprises, by mass, less than or equal to 0.03% of C, less than or equal to 0.8% of Si, less than or equal to 1.2% of Mn, less than or equal to 0.035% of P, less than or equal to 0.020% of S, 24.0-26.0% of Cr, 6.0-8.0% of Ni, 0.24-0.32% of N, 3.0-5.0% of Mo, less than or equal to 0.5% of Cu and the balance Fe. The method comprises the steps that a continuous casting blank is heated in a multi-step temperature difference mode, the temperature of a first temperature step is controlled to range from 400 DEG C to 500 DEG C, and heat preservation is conducted for 100-130 min; raising the temperature to a second temperature step in a linear temperature raising manner, controlling the temperature of the second temperature step to be 1000-1100 DEG C, and keeping the temperature for 170-190 minutes; raising the temperature to a third temperature step in a linear temperature raising manner, controlling the temperature of the third temperature step to be 1250-1300 DEG C, and keeping the temperature for 170-190 minutes; rolling is conducted, the heated continuous casting billet is subjected to multi-pass rolling in a broadening longitudinal rolling mode, the finish rolling temperature is controlled to be 1000 DEG C or above, and ACC rapid cooling is adopted after rolling, and by means of the method, a plate with the thickness larger than or equal to 100 mm and the width larger than or equal to 2000 mm can be prepared for rolling, so that the plate in the hot rolling state is free of sigma phase, and the surface and the edge are free of cracks.

A photocurable sol-gel composition for preparing a transparent and crack-free glass body, wherein the composition comprises a silica sol-gel precursor, a photopolymerizable monomer, a transition metal precursor, an organic solvent, and water. Also disclosed are methods of making the photocurable sol-gel compositions and methods of making transparent and crack-free glass objects from the photocurable sol-gel compositions.