3680 results about "Hardness" patented technology

Provided is a high-strength steel sheet having excellent member strength, ductility, stretch flangeability, bendability of a shear end surface, and low-temperature toughness. A high-strength steel sheet having a prescribed component composition and a steel structure in which the area ratio of martensite is 10%-80%, the area ratio of bainite is 2%-70%, the area ratio of ferrite is 80% or less, and the area ratio of retained austenite is 15% or less at a position at 1 / 4 of the sheet thickness. The ratio of the number of martensite blocks in which metastable carbides are present relative to the number of martensite blocks is 2% or more, and the standard deviation [sigma] n of the nano-hardness relative to the average value [Hn] ave of the nano-hardness is 0.60 x [Hn] ave or less when the nano-hardness at 225 points or more is measured at a position of 1 / 4 of the sheet thickness.

The invention discloses a powder metallurgy gear hardness detection method and system, and belongs to the technical field of metallurgy gears, and the method comprises the steps: obtaining a to-be-detected gear three-dimensional model, and dividing a hardness evaluation region; a thermal response image is collected, a thermal response time gradient parameter TRTG is extracted, and a thermal diffusion characteristic matrix T is formed; establishing a hardness initial model H1 based on the TRTG and compactness; constructing a finite element stress field model, extracting a stress distribution modulation coefficient SDMC, and forming a stress characteristic matrix S; performing weighted correction on H1 based on T and S, and establishing a comprehensive hardness prediction model H2; outputting a hardness prediction result of the whole gear and the key area, and identifying a potential weak area; according to the method, thermal response and stress modulation parameters are fused, non-destructive and high-resolution hardness distribution prediction is achieved, and the method is suitable for quality evaluation and failure early warning of the powder metallurgy gear of a complex structure.

The purpose of the present invention is to provide: a high-strength steel sheet that has a tensile strength of 980 MPa or greater and that is excellent in ductility, fatigue strength, and blanking properties; and a method for manufacturing the same.　The high-strength steel sheet is characterized by: having a prescribed component composition; the main phase being a bainite phase composed of granular bainite and upper bainite having an area ratio of 85% or greater; the area ratio of a hard second phase that includes fresh martensite and / or a residual austenite phase being less than 15%; the area ratio of the granular bainite to the area ratio of the upper bainite in the bainite phase being 5% to 40%; the difference |Hv1 - Hv2| between the hardness Hv1 at the 1 / 2 position the sheet thickness and the hardness Hv2 at the 1 / 4 position of the sheet thickness being 30% or less in relation to 0.3 TS; and the average crystal grain size of the upper bainite phase being 7 μm or less.

The invention provides a material cutting method and device, a medium and electronic equipment, and relates to the technical field of material processing.The method comprises the steps that an image of a material is obtained, and hardness distribution, texture and defect positions of the material are extracted from the image of the material; according to the defect position of the material, a plurality of initial cutting paths are generated with the purpose of minimizing the cutting length and the corner and the constraint condition of avoiding the defect position of the material; according to the hardness and the texture of the material, the optimization algorithm is adopted to optimize the multiple initial cutting paths to obtain the optimal cutting path, and the material is cut according to the optimal cutting path, so that the optimal cutting path of the material is determined by referring to the hardness distribution, the texture and the defect position of the material, the cutting stress is effectively reduced, and the cutting efficiency is improved. By means of the technical scheme, cutting burrs are avoided, the flatness of the cutting face is improved, the production efficiency of cutting equipment is improved, and the problems that in a traditional cutting process, the cutting efficiency is low, and the quality is unstable are solved.

The purpose of the present invention is to provide: a high strength steel sheet and a high strength plated steel sheet which have a strength of 1180 MPa or more, which have excellent bendability and inter-steel-sheet cracking characteristics at spot-welding resistant parts HAZ, and from which it is possible to manufacture components with high dimensional accuracy; methods for producing the high strength steel sheet and the high strength plated steel sheet; and a member.　This high strength steel sheet has a prescribed component composition, has an effective Ti molar fraction (xTi, eff) of 0.001 or more as determined from xTi, eff = xTi-xN-xS (wherein each element symbol represents the molar fraction of a corresponding element in steel), and has a steel structure in which the area percentage of martensite is 80-99% and the total of the area percentage of ferrite and / or the volume percentage retained austenite is more than 0% but not more than 20% at a 1 / 4-position in the sheet thickness, the Si concentration at a 5-µm positon in the sheet thickness direction from the steel sheet surface is 0.10-0.60%, the number density of MnS present in Mn-segregated portions in the surface of the steel sheet is 5.0 pieces / mm2 or less, the standard deviation of Vickers hardness in the surface of the steel sheet is 15 or less, and the hardness fluctuation frequency per 1100 µm in the sheet width direction in the surface of the steel sheet is seven times or less.

The invention relates to the field of pipeline welding, in particular to a prediction model construction method, system and equipment of a heat affected zone and a prediction method. The method comprises the steps that phase change parameters of a metal microstructure phase change model are corrected based on a thermal simulation test; building a heat affected zone microstructure finite element prediction model according to the circumferential weld simulation calculation finite element model; and correction is carried out based on a heat affected zone hardness test and a small punch test correlation parameter correction method, and the heat affected zone strength prediction model is trained by using the expansion database to obtain the pipeline welding joint heat affected zone strength prediction model. Based on a material performance determination test, a finite element model construction method and a finite element model expansion database mode, the accuracy of the heat affected zone strength prediction model is greatly improved, the research cost is reduced, the prediction from a microstructure to macroscopic performance is realized, and the method is suitable for popularization and application. And the defect that the softening mechanism of the hot area material cannot be clarified by traditional macroscopic mechanical property test analysis is overcome.

The invention discloses a control method applied to self-piercing riveting, and relates to the technical field of self-piercing riveting control. According to the method, riveting material data are collected in real time through a multi-source data fusion interface, the high-dynamic deformation process of a riveting head is captured, deformation rate and rebound value characteristic values are extracted, and a multi-dimensional process parameter set is constructed. And comprehensively analyzing the hardness, thickness and plastic dissipation characteristics of the material, and establishing an anti-deformation capability evaluation function. By introducing the fluctuation characteristics of the punching force, the nonlinear relation between the punching force and the elastic deformation of the riveting rod is analyzed, a hybrid compensation model is constructed, and a riveting dynamic coupling compensation vector is output. And generating a compensation weight matrix through an adaptive optimization algorithm, and dynamically adjusting the stamping force and the displacement of the riveting rod in combination with an anti-saturation control strategy. And dynamically adjusting a gain parameter through multi-scale filtering and a Lyapunov stability criterion, and triggering iterative updating of a compensation weight parameter during out-of-tolerance so as to optimize a control effect. Riveting precision and stability are improved, and the service life of equipment is prolonged.

The invention discloses a rock crack evolution numerical simulation method based on data analysis, and relates to the technical field of rock mechanics engineering numerical simulation, and the method comprises the following steps: S1, obtaining microstructure data of a target rock, including a CT scanning image, an SEM image and mineral energy spectrum data; and S2, constructing a spatial distribution dynamic mechanical parameter field based on the microstructure data. According to the rock crack evolution numerical simulation method based on data analysis, a dynamic mechanical parameter field driven by a microstructure is constructed, so that the inherent defect that rock is simplified into a homogeneous material in a traditional method is overcome; microscopic characteristics such as mineral hardness gradient, grain boundary strength distribution and pore morphology are effectively quantified into an elastic modulus field, a tensile strength field and a fracture energy field which are spatially distributed, so that the numerical prediction of crack initiation and expansion truly reflects the inherent heterogeneity of the rock for the first time.

The invention discloses a die-casting process for a small cover plate of a motor end cover. The die-casting process comprises the following steps: step 1, raw material treatment; step 2, material melting operation; thirdly, die casting is conducted; 4, flushing a water gap; step 5, removing burrs; step 6, heat treatment before preparation; step 7, shape correction; 8, CNC machining is carried out; step 9, cleaning treatment; and step 10, packaging and warehousing. According to the invention, mechanical cleaning and acid pickling are carried out on the raw materials before melting operation is carried out on the cast aluminum, so that the purity of the raw materials is guaranteed, bubbles are prevented from being generated in the melting process, and the quality of the prepared product is improved; a modifier is added in the melting process to refine grains, so that the hardness and the corrosion resistance of the prepared product are improved; after die casting, pre-manufacturing heat treatment is carried out to optimize the machining performance of the plate, the process difficulty of CNC machining is reduced, meanwhile, the internal stress remaining in the plate is removed through the stress relief annealing process, and product deformation caused by the internal stress is prevented.

The invention provides a temporary bonding adhesive and a preparation method and application thereof, and the preparation raw materials of the temporary bonding adhesive comprise the following components by weight: 60-80% of an organic solvent; 20-35% of base resin; 0.1 to 1% of tackifying resin; 0.1%-1% of an antioxidant; and 0.1-1% of a wetting leveling agent. The temporary bonding adhesive provided by the invention has the properties of high hardness, smooth film surface, high adhesive strength, high chemical corrosion resistance and the like, and can be widely applied to wafer processing.

The high-steel-grade low-cost hot-rolled coil plate comprises the following chemical components: 0.040 to 0.065 percent of C, 0.20 to 0.35 percent of Si, 1.48 to 1.75 percent of Mn, less than or equal to 0.02 percent of P, less than or equal to 0.003 percent of S, 0.012 to 0.025 percent of Ti, 0.035 to 0.055 percent of Nb, 0.005 to 0.008 percent of RE, 0.15 to 0.20 percent of Cr, 0.0005 to 0.0020 percent of B, 0.002 to 0.004 percent of Mg, 0.025 to 0.050 percent of Als, less than or equal to 0.003 percent of Ca, less than or equal to 0.008 percent of N and the balance of Fe and inevitable impurities. The technological process comprises the steps of smelting, slab continuous casting, slab heating, rolling, cooling and coiling. Rt0.5 of the steel is 580-660 MPa, Rm is 650-750 MPa, A50 mm is larger than or equal to 28%, Rt0.5 / Rm is smaller than or equal to 0.90, the impact energy mean value Akv at the temperature of-40 DEG C is larger than or equal to 200 J, the drop weight DWTT mean value at the temperature of-20 DEG C is larger than or equal to 90%, the hardness value HV10 is smaller than or equal to 220, and the cold bending performance is qualified. The product provided by the invention has high strength and toughness and good welding performance, so that the product is more suitable for various complex and extreme service environments, and has higher safety in pipeline engineering.

A bottom dispensing package for a liquid composition includes a resiliently squeezable container for housing the liquid composition; and a base operably connected to the container, wherein the base comprises an orifice. The body of the base is at least partially made from an elastomer. The elastomer used in the base has a Shore A (Type A) hardness of from about 0 to about 80, and the shore A hardness is measured using the method described in ISO 868:2003.

The present invention provides a multi-piece solid golf ball including a core, an intermediate layer, and a cover, in which a large number of dimples are formed on an outside surface of the cover, and a relationship between a cover material hardness and a midpoint hardness (Cm) between a core surface and a core center satisfies the following condition:midpoint hardness (Cm) between core surface and core center>cover material hardness where hardness means Shore C hardness.Further, a surface hardness of the ball is optimized, a deflection of the ball when compressed under a predetermined load is optimized, and a lift coefficient and a drag coefficient at a predetermined Reynolds number and spin rate of the dimples are set within a predetermined range.

The invention belongs to the field of material mechanical property analysis, and particularly discloses a three-dimensional random field construction method and system for simulating the mechanical property of a lunar soil brick, and the method comprises the following steps: S1, obtaining hardness and elastic modulus corresponding to each sampling point on the simulated lunar soil brick; s2, determining an edge distribution function F1 of the hardness based on the hardness distribution of all the sampling points, and determining an edge distribution function F2 of the elastic modulus based on the elastic modulus distribution of all the sampling points; s3, based on a Copula function, combining the edge distribution functions F1 and F2 into a joint distribution function; and S4, determining a cross correlation coefficient between the hardness and the elastic modulus based on the joint distribution function, forming a cross correlation coefficient covariance matrix R, and further determining the lunar soil brick mechanical property random field. According to the method, the random field for simulating the mechanical property of the lunar soil brick is accurately modeled, and a scientific basis can be provided for design and selection of lunar building materials.

The invention belongs to the technical field of metal part surface modification, and relates to a composite strengthening method for a carburized surface of a high-bearing gear of an aero-engine. According to the method, high-hardness and high-density ceramic shots are adopted as media for high-energy mechanical shot peening strengthening, the advantage that the subsurface strain hardening effect of the contact strengthening technology is good and the barb-shaped distribution characteristic of mechanical shot peening residual compressive stress are utilized, extremely high residual compressive stress is introduced to the subsurface position, and the contact fatigue performance of the tooth surface of the gear is improved. High-frequency laser shot peening strengthening is used for secondary treatment, so that the surface layer of the material is subjected to plastic deformation, high-amplitude residual compressive stress is introduced into the surface layer of the material within the depth range of more than 500 microns by utilizing the advantage of large influence depth of laser-induced shock waves, and the residual compressive stress can inhibit fatigue crack initiation, has a certain depth and inhibits fatigue crack propagation; and the bending fatigue resistance of the root of the gear can be effectively improved. And an abrasive flow process is adopted, so that the roughness is reduced to be more than 0.4 mu m.

The invention discloses a formula, a coating and a method of a dual in-situ precipitation reinforced FeCoNiCr-based high-entropy alloy composite material with a low corrosion-wear synergistic effect. The Al-Co-Cr alloy material comprises the following components in atomic percent: 15 to 30 at% of Al, 10 to 25 at% of Co, 10 to 25 at% of Cr, 10 to 25 at% of Fe, 10 to 25 at% of Ni, 20 to 35 at% of Ti and 5 to 15 at% of C, the preparation method comprises the following steps: filling all metal powder and graphene powder into a ball-milling tank, adding grinding balls, filling argon, sealing, and ball-milling, so as to obtain mixed powder in which the surfaces of metal powder particles are uniformly coated with graphene. The high-entropy alloy composite material with high hardness, high wear resistance and high corrosion resistance is obtained by utilizing the solid solution strengthening effect and the multiple in-situ precipitation strengthening effect of micron-scale TiC and nano-scale precipitation B2. The prepared coating is uniform and compact in structure, is metallurgically bonded with a base material, and has excellent corrosion and friction resistance and low corrosion-wear synergistic effect.

The invention provides a mold surface repairing method and system based on laser cladding, and relates to the technical field of laser cladding, the method comprises the following steps: selecting a matrix material with a proper size, and pretreating the surface of the matrix material; according to the actual process requirements, the value range of laser cladding process parameters is determined, and a response curved surface model of the microhardness and the dilution rate is established; optimizing the response curved surface model, and obtaining an optimized process parameter combination by taking maximization of microhardness and minimization of dilution rate as targets; according to the optimized technological parameter combination, the laser cladding process is carried out, and a cladding layer is formed on the pretreated base material; and performing performance detection on the formed cladding layer, and adjusting process parameters according to a performance detection result until an optimal process parameter combination is determined. By means of the method, it can be guaranteed that the hardness of the cladding layer is stabilized within the ideal range, the mold repairing quality is remarkably improved, and the service life of the mold is remarkably prolonged.

The invention discloses a laser cladding preparation method for improving the wear resistance of a cladding layer by doping tungsten carbide. According to the method, cladding process parameters are preliminarily obtained based on finite element heat flow analogue simulation, cladding layer preparation is carried out, cladding quality characterization is carried out to obtain the optimal cladding process parameters, and finally the cladding layer with the wear-resistant characteristic is obtained. The method comprises the following steps: firstly, constructing a heat flow coupling three-dimensional model, carrying out grid division, establishing a heat source model, defining thermophysical parameters of tungsten carbide (10-15%) nickel alloy composite powder and a matrix, and determining simulated boundary conditions; setting a multi-factor process parameter combination to carry out numerical simulation calculation, and determining laser processing process parameters of laser power, scanning speed and light spot diameter; preparing a cladding layer on the surface of the nodular cast iron by using tungsten carbide (10-15%) nickel alloy composite powder through a laser cladding method; and carrying out microscopic morphology and microhardness experiments to carry out quality analysis verification on the cladding layer, determining the optimal process parameters of laser power, scanning speed and light spot diameter when the cladding layer has no obvious defect morphology and the hardness is higher than that of the raw material, and obtaining the laser cladding preparation method for improving the wear resistance of the cladding layer by doping tungsten carbide. The invention provides a new research method and a high-quality preparation approach for improving the wear resistance of the cladding layer by tungsten carbide, and can be widely applied to the fields of strengthening and repairing mining machinery, aerospace parts and the like.

The invention discloses a microcrystalline aluminum alloy and a preparation method and application thereof, and belongs to the technical field of microcrystalline aluminum alloy material preparation. The microcrystalline aluminum alloy disclosed by the invention comprises Al and the following components in percentage by weight: 0.5 to 4.0 percent of Si, 0.5 to 4.5 percent of Mg, 0.5 to 5.0 percent of Fe, 0.5 to 6.0 percent of Cu, 0.5 to 8.0 percent of Ni, 0 to 5.0 percent of Mn, 0 to 4.0 percent of Mo, 0 to 4.0 percent of Zr and inevitable impurities. The grain size of the microcrystalline aluminum alloy is smaller than 5 microns, the hardness is larger than or equal to 150 HB, the room-temperature tensile strength is larger than or equal to 450 MPa, the high-temperature tensile strength (200 DEG C) is larger than 200 MPa, and the flatness is smaller than or equal to 5 microns.

A tool includes a cemented carbide part and a maraging steel part, wherein the two parts are joined by brazing. The cemented carbide part has a hard phase embedded in a metallic binder phase matrix. The maraging steel part has a hardness of between 350 and 600 HV1 with a standard deviation between 0 and 20 HV1. A method of making such tool is also provided.

A sponge roller is provided with a shaft body 2, and a foam elastic layer 3 provided on the outer circumference of the shaft body 2. An average cell diameter of the foam elastic layer 3 is 20-100 μm, and a difference between a maximum value and a minimum value of hardness A of five points of the foam elastic layer 3 is less than 2.5 points.

The invention relates to a comprehensive performance verification method for a wear-resistant layer of a turbine blade, and belongs to the technical field of turbine blades, the comprehensive performance verification method comprises a melting performance test, a pressure-resistant performance test, a wear-resistant performance test, a high-temperature hardness test and a tension shear test, and the melting performance test is performed on a welding rod made of a first material; the first wear-resistant layer made of the first material is subjected to a pressure resistance test, the second wear-resistant layer and the third wear-resistant layer made of the first material are subjected to a wear resistance test, the fourth wear-resistant layer made of the first material is subjected to a high-temperature hardness test, and the blade crown wear-resistant layer made of the first material is subjected to a tension shear test. The device has the beneficial effects that a fusion performance test, a pressure resistance test, a wear resistance test, a high-temperature hardness test and a tension shear test are carried out on the welding rod made of the first material, so that the comprehensive performance test on the welding rod made of the first material is realized, and whether the welding rod made of the first material can be used for processing a blade or not is judged; and the machining quality and safety of the blade are ensured.

The invention belongs to the technical field of aluminum plate machining, and particularly relates to an aluminum plate longitudinal cutting device which comprises a supporting table, and a discharging roller and a collecting roller are arranged at the top of the supporting table. By arranging the induction coil, the first permanent magnet, the second permanent magnet and the electromagnetic heating plate, the aluminum plate which is not longitudinally cut is heated, the hardness and brittleness of the aluminum plate can be reduced, longitudinal cutting is smoother, the quality of finished products is improved, deformation of the aluminum plate is reduced during longitudinal cutting, and the cutting precision and stability are ensured; by arranging a fixing plate, a shaking plate, piezoelectric ceramic pieces, springs and the like, the two piezoelectric ceramic pieces are placed in a cutting gap of an aluminum plate, when a longitudinal cutter is abraded, the cutting gap can be enlarged, the shaking amplitude of the piezoelectric ceramic pieces in the cutting gap is increased under pushing of the first spring, output current is increased, and the cutting effect of the aluminum plate is improved. And the state of the longitudinal cutter can be conveniently monitored in real time for subsequent detection operation.

The invention relates to a method for solving strip-shaped defects on the surface of a cold-rolled coil. The method comprises the steps of redesigning components and hardness of a product, adjusting the hot rolling tapping temperature, increasing the cooling water amount during laminar cooling after hot rolling, reducing the coiling temperature and the like. According to the method for solving the strip-shaped defects on the surface of the cold-rolled coil, the hardness of a low-carbon steel material is improved, the compactness of a material structure is improved, oxide scale cannot be pressed into the surface of the hot-rolled coil, the slab heating tapping temperature is reduced, the coiling temperature of the hot-rolled coil is reduced, and therefore the problem that the oxide scale of the hot-rolled coil is pressed in is solved; and strip-shaped defects cannot be generated when the hot-rolled coil is further cold-rolled.

The invention relates to the technical field of anti-fatigue of steel parts, and discloses an anti-fatigue system and method for a high-hardness steel part based on ultrasonic-shot blasting composite strengthening. The method comprises the steps that the macroscopic geometrical morphology, the microstructure and the dynamic stress-strain data of a target steel part are collected through a multi-mode sensing system, and a multi-physics field digital twinborn model is constructed through fusion; on the basis of fatigue damage feature distribution in the model, sorting by using an enhanced decision tree model, and triggering parameter configuration by using a priority over-critical value; synchronously calculating ultrasonic field regulation and control parameters and shot blasting trajectory planning parameters through an adaptive neural network algorithm; the parameters are injected into a digital twin model to simulate material response and energy transfer, data such as a microdefect closed state are output, and a parameter correction signal is generated through multi-dimensional consistency inspection. According to the method, precise control over composite strengthening is achieved, and the anti-fatigue performance of the high-hardness steel part is effectively improved.

The invention relates to the technical field of remanufacturing, in particular to a 1Cr17Ni3 gear pump casting shell end face superficial crack damage repairing method which comprises the steps that cleaning is conducted, and defect positions are determined; marking the defect position, then extending in a polyline form to form two rings, and connecting the two rings by using a line segment; polishing to form an outer ring groove, an inner ring groove and a line segment groove for connecting the inner ring and the outer ring; demagnetization is carried out; carrying out laser cladding repair; liquid nitrogen treatment; carrying out cladding repair and liquid nitrogen treatment on the test block to verify the hardness performance; the end face subjected to cladding repair is polished; and cleaning and carrying out penetrant flaw detection, and if no defect exists, successfully repairing. Local repair of a small area of the end face is avoided, local deformation is avoided, and the sealing performance is enhanced; the restoration quality deterioration caused by heat accumulation is avoided; the equal-hardness cladding repair is realized; the problem that after the shell has magnetism, the repairing quality is reduced due to the fact that powder adheres to the end face continuously in the cladding process is solved.

The invention relates to the technical field of material metallurgy, and discloses high-wear-resistance hot-rolled round steel for titanium-containing steel balls and a preparation method thereof.The round steel comprises 0.60%-0.67% of C, 1.40%-1.60% of Si, 0.70%-0.90% of Mn, smaller than or equal to 0.020% of P, smaller than or equal to 0.015% of S, 0.70%-0.90% of Cr, 0.10%-0.15% of Ti, smaller than or equal to 0.30% of Ni, smaller than or equal to 0.40% of Cu, smaller than or equal to 0.05% of Al, smaller than or equal to 0.0020% of O, smaller than or equal to 0.0002% of H and smaller than or equal to 0.0035% of N; and the balance of Fe and inevitable impurities. Through the high-titanium-low-nitrogen microalloying design, the technical contradiction that the toughness is remarkably reduced when the strength and the hardness of traditional high-carbon steel ball steel are improved is solved, and excellent synergistic improvement of the strength, the hardness and the toughness is achieved.

To provide a golf ball which reduces the distance by which an average hitter loses carry when hitting with a driver and when hitting with an iron, even if the distance by which a long hitter loses carry is increased when hitting with a driver.SOLUTION: The present invention provides a multi-piece solid golf ball including a core, an intermediate layer, and a cover, in which a large number of dimples are formed on an outside surface of the cover, and a relation between a cover material hardness and a midpoint hardness (Cm) between a core surface and a core center satisfies the following condition: midpoint hardness (Cm) between the core surface and the core center>the cover material hardness where hardness means Shore C hardness. Further, a surface hardness of the ball is optimized, a deflection of the ball when compressed under a predetermined load is optimized, and a lift coefficient and a drag coefficient at a predetermined Reynolds number and spin rate of the dimples are set within a predetermined range.SELECTED DRAWING: Figure 1

The invention relates to the technical field of material science, and particularly discloses a glaze performance evaluation method and system based on multiple application scenarios, and the method comprises the steps: obtaining the original data of the hardness value and wear loss of glaze, carrying out the standardization processing, calculating the hardness distribution index and wear resistance index, and carrying out the comprehensive analysis and classification of the glaze, thereby achieving the evaluation of the performance of the glaze. Qualified glaze and unqualified glaze are distinguished; then carrying out high-temperature stability test on the qualified glaze, and screening out the glaze with high thermal stability; and finally, a particle swarm optimization algorithm is adopted to search for an optimal solution of a hardness value and a wear loss regulation interval, and it is ensured that the glaze shows excellent performance in a changeable application environment. Through the systematic evaluation process, the problems of fuzzy standard, lack of scientific basis, poor performance consistency and low evaluation efficiency in a traditional evaluation method are solved, the consistency and reliability of glaze performance are effectively improved, the product quality is ensured, and the evaluation efficiency is remarkably improved.

Provided is a layer structure, preferably a security form in a book cover, particularly preferably a security form in a book cover for identification or security documents, comprising at least a) a first radiation-engravable layer a) containing at least one polymeric material; and b) at least one further layer b) containing at least one polymeric material, preferably a thermoplastic elastomer, preferably a thermoplastic polyurethane with a hardness of ≥40 Shore A according to DIN ISO 7619-1-2012-2 to ≤95 Shore D according to DIN ISO 7619-1-2012-2; wherein the further layer b) overlies the first layer a) at least partly to form an overlapping region, and wherein a coherent engraving partly extends in the overlap region, preferably in the further layer b), and partly in the portion of layer a) that extends outside the overlap region, most preferably exclusively in the further layer b). The invention also relates to a method for producing this layer structure and to a laminate comprising such a layer structure and to the use of the layer structure in a security document.