90results about How to "Increased tensile strength at room temperature" patented technology

The invention discloses a preparation method for a ceramic matrix composite bolt, which is characterized in that the method comprises the following steps: producing a fiber prefabricated product by shaping with a graphite plate after alternatively laminating a 1K carbon fiber 0/90 degree positive ply and a plus/minus Theta inclined ply; depositing a pyrolysis carbon interface layer on the prefabricated product and then depositing a silicon carbide matrix on the two-dimensional sheet with a deposited pyrolysis carbon interface layer to produce a semi-finished product of ceramic matrix composite sheet which is cut to form a bolt blank; grinding wheel and tapping the bolt blank; lastly obtaining the product of C/SiC composite bolt after many times of infiltration pyrolysis of polycarbosilane and continuing CVI depositing of SiC anti-oxidation coating. By the method, the bolt is processed and tapped on the semi-finished ceramic matrix composite prefabricated product which is not fully deposited and dense, so that the diamond grinding wheel wear is slow and the production cost is reduced. The technology of CVI combining with PIP process enables the elongation breaking strength of composite bolts to improve from 180 to 190MPa in prior art to 210 to 230MPa.

The invention relates to a repeated solid solution aging thermal treatment process of titanium alloy. The process includes the steps that a titanium alloy forge is subjected to heat preservation at the temperature T for t minutes, wherein T is larger than or equal to Tbeta-15 DEG C but smaller than or equal to Tbeta+15 DEG C, t is equal to eta*delta max, delta max is the maximum section thickness of the forge and is shown in millimeters, and eta is the heating coefficient and ranges from 0.2 min/mm to 0.8 min/mm; then the forge is discharged out of a furnace to be air-cooled or wind-cooled or water-cooled to be at the room temperature, then the cooled forge is subjected to heat preservation at the temperature of T for t minutes, wherein T is larger than or equal to Tbeta-25 DEG C but smaller than or equal to Tbeta-50 DEG C, the computational formula of t is as above, namely t=eta*delta max, and the heating coefficient eta ranges from 0.3 min/mm to 1.2 min/mm; then the forge is discharged out of the furnace to be air-cooled or wind-cooled or water-cooled to be at the room temperature, the cooled forge is subjected to heat preservation at the temperature T ranging from 540 DEG C to 600 DEG C, and the heat preservation time t ranges from 0.5 hour to 2 hours; the forge is discharged out of the furnace to be air-cooled to be at the room temperature, the cooled forge is subjected to heat preservation at the temperature T ranging from 400 DEG C to 540 DEG C, and the heat preservation time t ranges from 4 hour to 24 hours; and then the forge is discharged out of the furnace to be air-cooled to be at the room temperature. The repeated solid solution aging thermal treatment process of the titanium alloy is suitable for thermal treatment of near-beta type, metastable beta type and steady beta type ultrahigh-toughness titanium alloy so as to obtain required microscopic structures with high overall performance and multi-scale precipitated phases mixed.

The invention discloses an Nb-Si-Ti-Ta-B alloy material which is prepared from the following raw materials according to the following atom percentage: 6-20% of Si, 16-30% of Ti, 5-15% of Ta, 2-8% of B and the rest of Nb and unavoidable impurities. In addition, the invention also discloses a method for preparing the Nb-Si-Ti-Ta-B alloy material. The method comprises the following steps: 1, silicon powder, titanium powder, tantalum powder, boron powder and niobium powder are uniformly mixed and the mixture is compacted to form an electrode, and electric arc melting is carried out to obtain an alloy ingot; and 2, the alloy ingot undergoes extrusion so as to obtain the Nb-Si-Ti-Ta-B alloy material. Tensile strength of the Nb-Si-Ti-Ta-B alloy material under the condition of 1300 DEG C is 267MPa-425MPa. Ductility and toughness at room temperature, room-temperature mechanical property and high temperature tensile strength of the Nb-Si-Ti-Ta-B alloy material are well balanced.

The invention relates to a preparation method of a fine grain magnesium alloy. In the method, the preheating temperature of a mould is 350+/-5 DEG C; a magnesium alloy blank is subjected to at least five passes of extrusion and deformation; the preheating temperature of the magnesium alloy blank is 250+/-5 DEG C-380+/-5 DEG C; the extrusion rate is 2mm/s-15mm/s, and the extrusion direction each time is different; and the preheating temperature of the magnesium alloy blank changes from high to low, and the extrusion rate is varied from large to small. According to the preparation method provided by the invention, a multi-pass multi-direction temperature-variable extrusion technology is adopted, i.e., the temperature and extrusion rate of the magnesium alloy blank are gradually reduced along with the increase of extrusion pass, and forces are applied in the different directions of magnesium alloy so as to carry out extrusion and deformation, thereby improving the deformation nonuniformity of a magnesium alloy structure in the conventional isothermal extrusion deformation and preventing full growth and grain mixing of dynamically recrystallized grains due to high temperature in the extrusion process. Thus, the grains of the magnesium alloy obtained by using the multi-pass multi-direction temperature-variable extrusion deformation are obviously fined, and the size of the grain is uniform.

The invention provides an extrusion type aluminium alloy which belongs to the technical field of aluminium alloy preparation. The aluminium alloy comprises the following components by mass percent: 4.0-5.5% of Zn, 1.0-2.0% of Mg, 0.6-0.8% of Mn, 0.3-0.8% of Cu, 0.3-0.5% of Cr, 0.05-0.3% of Zr, 0.03-0.1% of rare earth element, no more than 0.3% of unavoidable impurity elements in total and the balance of aluminium. The aluminium alloy has the tensile strength of 396.17-540.03MPa and the yield strength of 303.61-480.13MPa at room temperature; and the aluminium alloy after fusion welding has the tensile strength of 389.17-530.03MPa and the yield strength of 292.61-460.13MPa, and the constituents of welding wires and matrixes are consistent in a welding process. The aluminium alloy can be used for solving a problem that the welding performance and high strength of the conventional aluminium alloy is difficult to match. The aluminium alloy is simple in operation and convenient in industrial production.

The invention discloses a rare earth magnesium alloy and a preparation method thereof. The rare earth magnesium alloy contains the following components in percentage by mass: 8.4-8.7% of Al, 0.85-0.89% of Zn, 0.28-0.30% of Mn, 0.39-1.21% of Nd, 0.41-0.43% of Er, less than 0.04% of impurity elements (Si, Fe and Cu) in total, and the balance of Mg. According to the method, rare earth elements Nd and Er are compounded and added in a magnesium alloy by smelting so as to modify the magnesium alloy and the obtained casting-state rare earth magnesium alloy is subjected to T6 heat treatment. Compared with the prior art, the rare earth magnesium alloy prepared by the method is relatively high in room-temperature tensile strength and high-temperature tensile strength and the plasticity is enhanced greatly.

The invention discloses a method for improving the room-temperature tensile property of a Ti-48Al-2Cr-2Nb alloy through adding of nano Y2O3, and belongs to the field of room-temperature mechanical properties of metal materials. The method for improving the room-temperature tensile property of the Ti-48Al-2Cr-2Nb alloy through adding of the nano Y2O3 aims at solving the problem that an existing directly-casted Ti-48Al-2Cr-2Nb alloy is coarse in structure, and serious in segregation. The method comprises the steps that nano Y2O3 particles are added in the Ti-48Al-2Cr-2Nb alloy, a water cooled copper crucible is adopted to induce a solidification shell smelting furnace, and under the high-vacuum/argon environment, through the melt reaction, a full-lamellar structure with the fine Y2O3 particles evenly distributed in a dispersed manner is directly generated. After the nano Y2O3 is added, the room-temperature tensile strength of the alloy is obviously improved, and the room-temperature plasticity of the alloy is greatly improved.

The invention belongs to the technical field of metal material thermal treatment and particularly relates to a processing method for improving corrosion resistance of an Mg-Y-Nd based alloy. The method comprises the steps that the to-be-processed alloy is subjected to deep cooling and solid solution treatment, soaked in a liquid nitrogen environment for quenching after being treated, and placed inthe liquid nitrogen environment after being quenched; and then the alloy is subjected to deep cooling aging treatment again, soaked in the liquid nitrogen environment for quenching after being treated, and placed in the liquid nitrogen environment after being quenched, the sample is completely stabilized at the liquid nitrogen temperature of minus 196 DEG C, and thus the magnesium alloy with thecorrosion resistance improved is obtained. By adoption of the method, the corrosion resistance of the Mg-Y-Nd based alloy can be remarkably improved while the excellent mechanical performance is ensured. The application range of the Mg-Y-Nd based alloy treated by the deep cooling treatment process is broad.

The invention provides a stainless steel submerged-arc welding strip with improved room temperature tensile strength. The stainless steel submerged-arc welding strip with improved room temperature tensile strength comprises the following components by mass percentage: less than or equal to 0.020 of C, 0.30-0.65 of Si, 1.0-2.5 of Mn, less than or equal to 0.01 of S, less than or equal to 0.025 of P, 19.5-21.0 of Cr, 9.0-11.0 of Ni, less than or equal to 0.50 of Mo, less than or equal to 0.50 of Cu, less than or equal to 0.50 of Co, 0.07-0.20 of N and the balance Fe. After welding and thermal treatment, the room temperature mechanical properties of deposited metal is as follows: Rm is greater than or equal to 520Mpa, Rp0.2 is greater than or equal to 260MPa, and A4 is greater than or equal to 35%. Compared with the prior art, the stainless steel submerged-arc welding strip with the improved room temperature tensile strength has the advantages that the room temperature tensile strength of the welding strip is improved, and the manufacturing requirements of AP1000 and AP1400 nuclear power equipment are satisfied.

The invention discloses heat treatment method of an aluminum alloy. The aluminum alloy comprises, by mass, 8%-10% of metal fibers, 5.5%-7.2% of Mg, 1.0%-2.5% of Zn, 0.8%-1.8% of Cu, 0.08%-0.18% of Sc,0.08%-0.18% of Zr, 0.12%-0.22% of Y, 0.02%-0.07% of Si, 0.02%-0.07% of Mn, 0.01%-0.03% of Er, 0.01%-0.03% of Ce, no more than 0.15% of impurities, and the balance Al. The heat treatment method comprises the steps that S1, high-temperature heat treatment is conducted on the aluminum alloy at the temperature of 500-600 DEG C, and after high-temperature heat treatment, quenching is conducted on thealuminum alloy with PAG quenching liquid, so that the aluminum alloy subjected to high-temperature treatment is obtained, wherein the content of PAG polymers in the PAG quenching liquid is 15-60 wt%,the temperature of the PAG quenching liquid is 40-80 DEG C, and the stirring speed of the PAG quenching liquid is 100-200 r/s; S2, cold-deformation treatment is conducted on the aluminum alloy subjected to high-temperature treatment, so that the aluminum alloy subjected to cold deformation is obtained; S3, the aluminum alloy subjected to cold deformation is tempered at the temperature of 300-400 DEG C for 1-2 h; and S4, afterwards, annealing treatment is conducted on the aluminum alloy at the temperature of 100-160 DEG C for 6-8 h, and thus, the strength of the aluminum alloy is improved. Theinvention further provides the aluminum alloy prepared through the heat treatment method.

The invention belongs to the alloy steel field, in particular to a nickel base expanding alloy used on an intermediate temperature flat-plate type solid oxide fuel cell metallic interconnector. The alloy has chemical compositions (in weight percent): Mo 18.0 to 24.0 percent, Cr 10.0 to 14.0 percent, Co 2.5 to 3.5 percent, W 3.5 to 4.5 percent, Ti 1.0 to 1.5 percent, Mn 0.8 to 1.2 percent, Si<=0.05 percent, La<=0.02 percent, Y<=0.01 percent, C<=0.005 percent, S<=0.005 percent, P<=0.005 percent, balance Ni. Compared with the prior art, the alloy has the advantages of good compatibility of expansion properties with surrounding materials in the solid oxide fuel cell operational environment, good pyroconductivity, oxidation resistance and mechanical property. The tensile strength of alloy is higher than 1100MPa under room temperature, the elongation at break is higher than 18 percent, and the coefficient of expansion from the room temperature to 1000DEG C is controlled under 15x10<-6>DEG C<-1>.

The invention relates to an alkaline-earth element modified heat-resistant magnesium alloy. The magnesium alloy comprises the following components by weight percent: 2.5-3.4% of Al, 0.5-1.4% of Si, 0.05-0.14% of Mn, 0.05-1.54% of Sr and the balance of Mg. The magnesium alloy is modified by adding Mg-Si and Al-Sr intermediate alloys to the magnesium alloy by a smelting method, and T6 heat treatment is carried out on the obtained as-cast heat-resistant magnesium alloy. Compared with the prior art, the prepared heat-resistant magnesium alloy has higher room temperature tensile strength and high temperature tensile strength and better plasticity.

The invention relates to a method for improving the fluidity of water glass for casting through polyethylene glycol. The method comprises the steps that the polyethylene glycol serves as a modifier tobe added in a water glass solution for making a reaction, and a modified water glass binder can be obtained; and under the same preparation conditions, compared with a water glass binder without thepolyethylene glycol modifier, the fluidity of the modified water glass binder is improved, the normal temperature tensile strength is improved, and the normal temperature flexure strength is reduced.The fluidity of the modified water glass binder is good, and the modified water glass binder is suitable for sand mold 3DP manufatcuring.