37results about How to "Improved damage tolerance performance" patented technology

The invention relates to a high-damage tolerance type ultrahigh strength aluminum alloy and a preparation method thereof. The high-damage tolerance type ultrahigh strength aluminum alloy comprises the following components in percentage by weight: 8.5-10.0 percent of Zn, 1.0-2.5 percent of Mg, 1.0-2.0 percent of Cu, 0.06-0.20 percent of Zr, 0.02-0.05 percent of Ti, not more than 0.08 percent of Fe, not more than 0.06 percent of Si and the balance of Al and unavoidable impurities, wherein the Fe content is larger than Si content. The method comprises the following steps: firstly, smelting and casting; then carrying out homogenization on an alloy casting blank by stages, carrying out hot rolling on the homogenized casting blank and carrying out solid dissolution on a hot rolled plate; prestretching the plate in four hours after quenching; and finally immediately carrying out double-stage ageing processing on the prestretched plate. The obtained alloy has higher strength and damage tolerance and is suitable for being applied in an airplane part exposed in the atmospheric environment for a long time.

A manufacturing method of a carbon fiber metal composite laminated plate relates to a manufacturing method of a fiber metal composite laminated plate. The method aims at solving the problems that no manufacturing methods for manufacturing aircraft structural material with high specific stiffness, high specific strength, tenacity and workability exist in China. The method comprises the following steps of: carrying out surface treatment to three pieces of metal plates; winding a carbon fiber composite material layer which is soaked in liquid cement on one of the metal plates, wherein, the liquid cement is prepared by epoxy resin, a metaphenylene diamine curing agent and an anhydrous alcohol solvent according to the mass ratio of 1:0.1 to 0.18:0.15 to 0.2; fixedly arranging another two metal plates on the upper surface and the lower surface of the carbon fiber composite material layer so as to be integrally put into a mould, and then treated with mould assembling, drying, solidification by adopting the method of gradient temperature increasing, and demoulding. The manufacturing method of the invention is simple and is easy for operation. The carbon fiber metal composite laminated plate manufactured by the method of the invention has the advantages of high specific stiffness, high specific strength, also high tenacity and workability of metal material, good fatigue property, and good damage tolerance capability.

The invention discloses a preparation method of an Al-Cu-Li-X series aluminum lithium alloy sheet. The sheet prepared by the method is 0.8mm-8.0mm in thickness. The method comprises the following steps: cogging and hot-rolling homogenized slab ingots to a specified thickness and coiling; carrying out annealing treatment, uncoiling and carrying out band-type cold-rolling; carrying out intermediate annealing according to deformation during cold-rolling, thus obtaining the sheets with uniform thicknesses. The sheets can be in different states after being subjected to solution treatment, prestretching and aging treatment, so as to meet different usage requirements. Compared with the prior art, the aluminum lithium alloy sheet with high surface quality, uniform sheet size and smooth sheet shape is prepared by the method through band-type cold-rolling. The sheets can be in different states by different heat-treating processes, so as to meet usage requirements under different application conditions.

The invention discloses a heat treatment process of a titanium alloy, and belongs to the technical field of material science. The heat treatment process is mainly as follows: the heating temperature T of the first heating treatment is greater than or equal to (Tbeta-50) DEG C and less than or equal to (Tbeta+60) DEG C, the holding time t is equal to eta 1*delta max, the delta max is the maximum section thickness of a titanium alloy forged piece, the eta 1 is a heating coefficient, the value of the heating coefficient is 0.6-1.5min/mm, after the heat preservation on the forged piece is completed, the forged piece is discharged from a furnace and is subjected to air cooling, wind cooling, oil cooling or water cooling to a room temperature; the heating temperature T of the second heating treatment is greater than or equal to 650 DEG C and less than 780 DEG C, the holding time t is equal to (eta 2*delta max)/2, the delta max is the maximum section thickness of the titanium alloy forged piece, the eta 2 is a heating coefficient, the value of the heating coefficient is 0.3-1.2min/mm, after the heat preservation on the forged piece is completed, the forged piece is discharged from the furnace and is subjected to air cooling to a room temperature; and the heating temperature T of the third heating treatment is greater than or equal to 480 DEG C and less than 650 DEG C, the holding time t is greater than or equal to 240min and less than or equal to 600min, and after the heat preservation on the forged piece is completed, the forged piece is discharged from the furnace and is subjected to air cooling to a room temperature. The heat treatment process solves the problems that after near-beta, metastable beta-type and fully-stable beta-type titanium alloys are subjected to solution treatment and ageing, the side and heart of the forged piece have large difference in structure properties, and is particularly suitable for preparing the high-strength titanium alloy forged piece with uniform structure properties and a large section/variable cross section.

The invention provides a method of forming a fiber-aluminum alloy composite part. The method comprises the following steps: 1, cutting an aluminum alloy plate and a fiber cloth according to a shape ofthe part; 2, subjecting the aluminum alloy plate to solid solution treatment, and immediately subjecting the aluminum alloy plate from the solid solution treatment to pre-pressing treatment, allowingfor uniform distribution of gridded grooves on a surface, glued to the fiber cloth, of the aluminum alloy plate, and then subjecting the pre-pressed aluminum alloy plate to quenching treatment; 3, subjecting the quenched aluminum alloy plate to degreasing treatment, and subjecting the fiber cloth to pre-impregnation treatment in an epoxy resin glue solution; 4, forming a sandwich plate in the order of aluminum alloy plate, fiber prepreg and aluminum alloy plate, and pre-pressing the sandwich plate; and 5, putting the obtained sandwich plate into a stamping die, closing the die and holding thetemperature, and then carrying out solidification to obtain the fiber-aluminum alloy composite part. The method overcomes the shortcoming of low elongation rate during the formation of a fiber material and improves the strength of the composite material part.

The invention discloses a reinforced and toughened metastable beta titanium alloy. The reinforced and toughened metastable beta titanium alloy comprises the following elements in percentage by weight:3.6-6.0% of Al, 3.0-5.0% of Mo, 3.0-5.0% of V, 2.0-5.9% of Cr, 1.0-4.0% of Nb, 0.4-2.0% of Fe, 0.05-0.3% of O, and the balance of Ti and inevitable impurities; the total quantity of impurity elementsis not higher than 0.15%; and the weight percentage sum of all the components is 100%. The invention further discloses a preparation method of the titanium alloy. Through changing of the adding formof Nb element, formation of the high-density inclusion defect of Nb-enriched non-melted blocks is prevented. Step variable-power smelting process parameters are adopted, so that the ingot chemical component uniformity is improved, and the component uniformity and the performance stability of the WSTi544432 metastable beta titanium alloy are guaranteed.

The invention discloses a high-strength and high-toughness titanium alloy with good additive manufacturing forming performance and used at the high temperature of 600 DEG C, and belongs to the technical field of metal additive manufacturing. The titanium alloy comprises the following components in percentage by mass: 6.2-7.5% of Al, 1.2-4.5% of V, 1.2-4.5% of Mo, 0.5-2.0% of Nb, 3.2-9.6% of Zr, less than or equal to 0.02% of Mn, less than or equal to 0.02% of C, less than or equal to 0.01% of Ni, less than or equal to 0.20% of Si, less than or equal to 0.20% of Sn, less than or equal to 0.04% of Cr, less than or equal to 0.02% of O, less than or equal to 0.01% of P, less than or equal to 0.01% of S, less than or equal to 0.006% of N and the balance of Ti, and the mass percentage ratio of Al to (V + Mo + Nb + Zr) is 5:(4.2-13). Through alloy component design, alpha phase refining, strength improving, beta phase content optimizing, plasticity improving and melt thermal stability enhancing are achieved, the toughness of the alloy at the high temperature of 600 DEG C is improved to the maximum degree, and the alloy can be used for additive manufacturing forming.

A method for improving the damage tolerance performance of an Al-Cu-Mg alloy is to carry out a solid solution + water quenching treatment on an Al-Cu-Mg alloy plate, and then perform a cold rolling pre-deformation treatment with a deformation amount of 6-15%, and then Perform aging treatment. The process of the invention is simple and reasonable, through cold rolling with small deformation amount after solid solution quenching, a certain compressive stress layer is generated on the surface of the plate, and the formation and expansion of cracks under the action of fatigue stress are effectively inhibited. With the natural aging treatment, the surface layer has a large density of dislocations due to the pre-deformation of cold rolling, which makes the alloy precipitate large-sized Cu-Mg atomic clusters during the natural aging process, and increases the Cu/Mg mass ratio of the clusters, so that The surface layer of the plate produces a large order strengthening effect and modulus strengthening effect; artificial aging treatment can cause the plate to precipitate a fine and dispersed second phase, and at the same time, the higher density dislocations on the surface can form a finer and dispersed second phase on the surface of the plate. Two phases, thereby hindering the formation and propagation of fatigue cracks in the surface area, and improving the fatigue resistance damage tolerance performance of the plate. This surface-hard-core-tough structure can effectively improve the damage tolerance performance of the plate, and is suitable for industrial applications.

The invention discloses a heat treatment method for obtaining a high-toughness and high-damage-tolerance double-phase titanium alloy. The heat treatment method comprises the following steps of high-temperature annealing treatment, specifically, keeping the temperature for 0.1-2 hours at T1 temperature, reasonably controlling the cooling speed, preferably, controlling the temperature range from T1 to T-200 DEG C to be 2-50 DEG C/s, controlling the value range of T1 between Tbeta10 DEG C and T, controlling the value range of T between Tbeta10 DEG C and T, controlling the value range of T between Tbeta10 DEG C and T, wherein T is the beta transformation temperature of the double-phase titanium alloy. According to the method, the toughness and the damage tolerance performance of the double-phase titanium alloy are improved by controlling the heat treatment temperature and the cooling speed. The method can be used for the two-phase titanium alloy with two structures under the room temperature conditions of TC11, TA15, TC4, TC17, TC18 and the like, is not limited by the original manufacturing process of the titanium alloy, and is suitable for forge pieces, castings, welding pieces and additive manufacturing pieces of the two-phase titanium alloy.

A structural element includes the following elements: a carrier element, a reinforcing element, and a sheathing element. At least a portion of the reinforcing element is enveloped by the sheathing element and the reinforcing element is embedded in the carrier element. Materials of the elements are selected to inhibit crack initiation or propagation in the elements and/or from one element to another. An intermediate layer of a different material may be added between elements to further inhibit crack initiation and propagation and to inhibit corrosion, such as galvanic corrosion.

The invention provides a heat treatment process for allowing a TC21 alloy to obtain a basket-weave microstructure after superplastic deformation in a two-phase region. The heat treatment process includes the steps: firstly carrying out superplastic tensile of a TC21 tensile specimen at the temperature of 900 DEG C and a set strain rate until tensile failure; after tensile failure of the tensile specimen, immediately carrying out water cooling; cutting out a uniform-deformation part of the tensile-failure specimen to be used as a heat treatment specimen; carrying out first heat treatment on the heat treatment specimen, heating a heat treatment furnace up to 10-20 DEG C above a beta-phase transition temperature, putting the heat treatment specimen into the heat treatment furnace, carrying out heat preservation for 1 hour, and followed by carrying out first air cooling; then, carrying out second heat treatment on the heat treatment specimen, heating the heat treatment furnace up to 20-30 DEG C below the beta-phase transition temperature, putting the heat treatment specimen into the heat treatment furnace, carrying out heat preservation for 1 hour, and followed by carrying out second air cooling; and then, carrying out third heat treatment on the heat treatment specimen, heating the heat treatment furnace up to 360-370 DEG C below the beta-phase transition temperature, putting the heat treatment specimen into the heat treatment furnace, carrying out heat preservation for 4 hours, followed by carrying out third air cooling, and thus obtaining the basket-weave microstructure.

This invention discloses a high strength, high toughness and high damage-tolerance aluminum alloy with high zinc-content, which is composed of Zn 9-10 wt.%, Mg 2.0-2.5 wt.%, Cu 1.2-1.7 wt.%, Zr 0.2-0.5 wt.%, Fe less than 0.05 wt.%, Si less than 0.05 wt.% and Al as balance. The aluminum alloy is manufactured by: mixing the raw materials, smelting, casting into alloy ingots, melting the ingots at 780-800 deg.C, carrying out fast-solidification injection molding with inert gas as an atomization gas under 0.5-1.0 MPa. The aluminum alloy has such advantages as uniform component distribution, uniform microstructure and no segregation. After reasonable thermal treatment, the aluminum alloy has an ultimate tensile strength high than 750 MPa and an elongation rate of 8-11%. The fracture toughness and fatigue strength of the aluminum alloy are better than those of 7050T74 material. The aluminum alloy can be used as key structures in aerospace and aviation industry, nuclear industry and military industry.

The present invention provides aqueous compositions for making damage tolerant coatings comprising a blend of (i) from 2 to 30 wt. %, based on the total weight of solids in the composition, of an acid or anhydride functionalized polyolefin dispersion having an average particle size of from 0.2 to 5 microns, and (ii) a film forming dispersion of one or more epoxy resins chosen from epoxy resins having an epoxy equivalent weight (EEW) of from 150 to 4,000 having an average particle size of from 0.2 to 1.0 microns, wherein the polyolefin dispersion is stabilized with from 2 to 8 wt. %, based on the total weight of solids in the composition, one or more anionic surfactants, such as a sulfate containing surfactant, and, further wherein, the compositions have a pH of from 3 to 8.

The invention discloses a global control method and device for damage fracture of an integral panel structure, and relates to the field of aircraft structure damage tolerance design, and the method comprises the steps: building a global damage parameter matrix of the integral panel structure; determining a control constraint; selecting a first group of parameters, and establishing a three-dimensional shell finite element model containing at least three rib integral wallboard structures according to the first group of parameters; simulating a crack propagation track by using a finite element method based on the reinforced area and unit, and obtaining a change curve of the stress intensity factor along with the crack length; according to the change curve, calculating the crack propagation life, the residual strength value and the weight under the first group of parameters; judging whether the crack propagation life, the residual strength value and the weight meet preset conditions or not; and if any one does not meet the preset condition, returning to the step of selecting a second group of parameters. According to the method and device, the crack propagation speed is delayed to the maximum extent, the damage tolerance performance of the whole wallboard is improved, and rapid iteration of optimization design is guaranteed.