68results about How to "Improve grain boundary strength" patented technology

The invention discloses a production method of a high-strength, high-conductivity and heat-resistant copper alloy, and belongs to the technical field of copper alloy machining. Accoding to the production method of high-strength, high-conductivity and heat-resistant copper alloy, the inner liner of a crystallizer adopted in the upper-induced continuous casting process is a carbon-carbon composite material so as to ensure the lubrication, high heat conduction and high temperature resistance properties; the temperature of the upper-induced continuous casting is 1180-1230 DEG C, the casting temperature is low so that the problem that molten liquid in the crystallizer is difficult to solidify and the crystallizer inner liner is worn during casting can be effectively avoided; the pressure of protective gas nitrogen in the liquid surface of an upper-induced furnace is controlled to be 0.2-0.7 atmosphere, so that the phenomenon of solid-liquid interface separation in the crystallizer is avoided, and a copper-chromium alloy product with larger weight and length is produced; according to the production method of the high-strength, high-conductivity and heat-resistant copper alloy, the cheapelement (Mg) is used for replacing the rare noble metal, and the mechanical property and the softening resistance property of the copper-chromium alloy are improved; and the production method is a non-vacuum and short-process preparation technology, the cost is low, and the production method is suitable for large-scale industrial production and has important economic and social significances.

The present invention provides a non-oriented electrical steel sheet at low cost that has excellent magnetic properties and mechanical properties as well as excellent quality of steel sheet. The non-oriented electrical steel sheet has a chemical composition containing, by mass %, Si: 5.0% or less, Mn: 2.0% or less, Al: 2.0% or less, and P: 0.05% or less, in a range satisfying formula (1), and furthermore, C: 0.008% or more and 0.040% or less; N: 0.003% or less, and Ti: 0.04% or less, in a range satisfying formula (2), with the balance composed of Fe and incidental impurities:

300≦85[Si %]+16[Mn %]+40[Al %]+490[P %]≦430  (1)

0.008≦Ti*<1.2[C %]  (2),

where Ti*=Ti−3.4[N %].

A process for preparing the nano-class composite silicon nitride-titanium carbide ceramic in which the granularities of silicon nitride are distributed by dual peaks includes such steps as mixing Si3N4 nanoparticles and TiC nanoparticles with Si3N4 micron-particles, and sintering by segmentally raising temp and pressurizing. Its advantages are high strength, toughness, heat shock resistance and antioxidizing performance.

The invention provides an austenitic stainless steel plate which is composed of the following chemical compositions in percentage by weight: less than or equal to 0.03% of C, 0.3-1.0 % of Si, 0.8-2.0% of Mn, less than or equal to 0.003% of S, less than or equal to 0.03 % of P, 16.0-20.0% of Cr, 10.0-14.0% of Ni, 1.0-3.0% of Mo, less than or equal to 0.08% of N, less than or equal to 0.004% of O, 0.005-0.01% of optional Ca and/ or 0.001-0.003 % of optional B and the balance of Fe and other inevitable impurities, wherein the weight percentage of Ni, Mn, N, C, Cr, Mo and Si also satisfies that the content of ferrite delta in the steel plate is less than 3%. Correspondingly, the invention also provides a manufacture method of the austenitic stainless steel plate. By the technical scheme, the austenitic stainless steel plate of the invention has good surface quality and does not have the surface defects, such as liner scale, inclusion, peeling, crazes and the like.

The invention belongs to the field of metal smelting, and relates to a 2-system aluminum alloy with high Fe and Ni content and a smelting and casting method thereof. The 2-system aluminum alloy comprises, in weight percent, 0.15-0.2% of Si, 1.4-1.6% of Fe, 1.4-1.6% of Ni, 2.6-2.8% of Cu, 1.7-1.9% of Mg, less than or equal to 0.1% of Zn, 0.06-0.09% of Ti, less than or equal to 0.1% of Mn, less thanor equal to 0.1% of Cr and the balance Al. The smelting and casting method includes the steps: performing smelting, refining, degassing, slag removal and casting on raw materials; performing castingby the aid of a semi-continuous casting process; adding 1.0-2.0% of yttrium aluminum intermediate alloys in the refining process; controlling casting temperature to be 690-700 DEG C, controlling casting speed to be 20-30mm/min, and connecting single water flow to be 15-16m<3>/h to obtain 2-system aluminum alloy cast ingots. The 2-system aluminum alloy cast ingots with high content of Fe and Ni produced by the smelting and casting method are less in shortcoming and good in heat resistance and has good economic benefits, finished product rate is increased, and energy consumption and production cost are reduced.

The present invention relates to the development of an alloy material with significantly improved low-temperature brittleness, recrystallization brittleness, and irradiation brittleness by the introduction of a recrystallization microstructure into an alloy, particularly a tungsten material, to significantly strengthen a weak grain boundary of the recrystallization microstructure. The present invention comprises the steps of: mechanically alloying at least one species selected from a group-IVA, VA, or VIA transition metal carbide and a metallic raw material; sintering base powders obtained through the mechanically alloying step, by using a hot isostatic press; and performing plastic deformation of at least 60% on the alloy obtained through the sintering step, at a strain rate between 10⁻⁵ s⁻¹ and 10⁻² S⁻¹ and at a temperature between 500° C. and 2,000° C. It is therefore possible to obtain an alloy material with significantly improved low-temperature brittleness, recrystallization brittleness, and irradiation brittleness.

The invention provides a heat treatment process capable of lowering ductile-brittle transition temperature and intergranular fracture ratio of turbine blades. When the heat treatment process is used, the problem that the process effect is susceptible to influences of chemical components of the raw material of the blades when the conventional sub-temperature annealing process is used to treat the turbine blades and the problem of high ductile-brittle transition temperature and intergranular fracture ratio of the turbine blades due to overlong high-temperature retention during heat treatment ofthe blades in the sub-temperature annealing process are solved. In the invention, the blades are uniformly placed in a common quenching material basket according to a technical scheme and then the quenching material basket is placed in a heat treatment quenching furnace. The heat treatment process is characterized in that: the blades are quenched twice in a quenching furnace; the temperature of primary quenching is 980 to 1070 DEG C; the temperature is kept constant for 1 to 3 hours; the cooling speed is 20 to 50 DEG C per minute; the temperature of secondary quenching is 900 to 1,000 DEG C; the temperature is kept constant for 15 to 120 minutes; the cooling speed is 30 to 50 DEG C minutes; and the temperature of the primary quenching is 20 to 100 DEG C higher than the temperature of the secondary quenching.

The invention belongs to the field of steel-making continuous casting production of micro-alloy high-strength steel, and discloses a method for improving the high temperature plasticity of steel basedon a synergistic effect of magnesium treatment and two-times cooling. By the synergistic effect of a magnesium treatment process and a novel two-times cooling control process, components, the size and the distribution state of second-phase particles in a micro-alloy high-strength steel casting blank can be effectively controlled, the thickness of a proeutectoid ferrite film distributed along an original austenite grain boundary is controlled, the percentage reduction of area of the casting blank is increased significantly through detection with Gleeble3800 and is higher than 50%. Thus the effects that method can significantly improve the high temperature plasticity of the micro-alloy high-strength steel and the surface crack defects of the casting blank can be overcome effectively are verified.

The invention discloses a surface modified coating cutting blade and a preparation method thereof. The cutting blade comprises a blade matrix and a coating deposited on the blade matrix, the coating contains an MT-TiZrCN coating and an outermost Al(Zr)2O3 modified coating with a corundum structure; the Al(Zr)2O3 modified coating has (300) crystal face strong texture orientation, and the strength ratio I(300)/I(110) of the orientation crystal surface is 0.5-2.5. The preparation method includes: sequentially depositing a TiN layer, an MT-TiZrCN coating, a TiCxNyOz layer, an alpha-Al2O3 layer and an Al(Zr)2O3 modified coating on the blade matrix, thus obtaining the surface modified coating cutting blade. The surface modified coating cutting blade provided by the invention has excellent heat resistance, anti-tipping performance and anti-adhesion performance, and is suitable for general milling processing and other aspects of steel and stainless steel.

The invention provides a doped perovskite solar cell. The doped perovskite solar cell comprises a substrate layer, a first charge transport layer, a passivated perovskite layer, a second charge transport layer and an electrode layer which are in contact in sequence, the passivated perovskite layer comprises a perovskite material and a self-repairing polymer; the self-repairing polymer is a polymethyl methacrylate-n-butyl acrylate copolymer. According to the perovskite solar cell, the self-repairing polymer containing the polar functional group carbonyl is added into the perovskite layer, the polymer can be coordinated with Pb < 2 + > or Sn < 2 + >, non-coordinated atoms at the grain boundary are passivated, and the function of passivating the grain boundary is achieved; meanwhile, the polymer has good self-repairing capacity, and the grain boundary strength in the polycrystalline perovskite thin film can be enhanced; in addition, the polymer has a hydrophobic property and can block water vapor invasion, so that the stability of perovskite is improved. The invention also provides a preparation method of the doped perovskite solar cell.

It is an objective of the invention to provide a low cost Ni-based casting superalloy suitable for casting articles having a far better balance among a high-temperature mechanical strength, a grain boundary strength and a oxidation resistance than conventional Ni-based superalloy cast articles. There is provided an Ni-base casting superalloy including: in mass %, 0.03 to 0.15% of C; 0.005 to 0.04% of B; 0.01 to 1% of Hf; 0.05% or less of Zr; 3.5 to 4.9% of Al; 4.4 to 8% of Ta; 2.6 to 3.9% of Ti; 0.05 to 1% of Nb; 8 to 12% of Cr; 1 to 6.9% of Co; 4 to 10% of W; 0.1 to 0.95% of Mo; 0.02 to 1.1% of Si and/or 0.1 to 3% of Fe; and the balance including Ni and incidental impurities.

The invention provides a method for improving the toughness of a 3D printing nickel-based superalloy part, and belongs to the technical field of 3D printing. The method comprises the steps of obtaining the 3D printing nickel-based superalloy part; making solution treatment to the 3D printing nickel-based high-temperature alloy part to obtain a nickel-based high-temperature alloy part subjected to solution treatment; performing hot isostatic pressure treatment to the nickel-based high-temperature alloy part subjected to solution treatment to obtain a nickel-based high-temperature alloy part subjected to hot isostatic pressure treatment; and heating the nickel-based high-temperature alloy part subjected to hot isostatic pressure treatment to 710 DEG C-730 DEG C and holding the alloy part for 3-8 h for the first time, and performing first aging treatment and air cooling to obtain the high-toughness nickel-based high-temperature alloy part. According to the nickel-based high-temperature alloy part treated through the method, at the temperature of 1000 DEG C, the yield strength ranges from 128 MPa to 142 MPa1000 DEG C, the tensile strength ranges from 150 MPa to 168 MPa, the ductility ranges from 17% to 19.5%, and the toughness is high.

Disclosed is a nickel base alloy which is substantially free of rhenium and has a solidus temperature of more than 1320° C. Precipitates of a γ′-phase are present in a γ-matrix with a fraction of 40 to 50 vol % at 1050° C. to 1100° C., and a γ/γ′ mismatch at 1050° C. to 1100° C. is from −0.15% to −0.25%. The alloy comprises 11 to 13 at % aluminum, 4 to 14 at % cobalt, 6 to 12 at % chromium, 0.1 to 2 at % molybdenum, 0.1 to 3.5 at % tantalum, 0.1 to 3.5 at % titanium, 0.1 to 3 at % tungsten. The tungsten content of the γ-matrix is greater than that in the precipitated γ′-phases.

Heat treatment of alloys having elements for improving grain boundary strength is disclosed. Components directly after castings often reveal low or no transverse grain boundary strength, so that cracks do appear and decrease the yield rate. The provided measures do not lead to low transverse grain boundary strength but maintains efficient grain boundary strength, so that the yield rate of components without cracks is increased.

The invention belongs to the technical field of metallurgy, and particularly relates to a high-strength hot-dip galvanized stamping car structure steel plate and a production method thereof. In view of the problems such as high mechanical property directionality and secondary processing brittleness after forming of an car structure steel plate prepared by an existing method, the steel plate is provided by the invention and is prepared from the chemical components in percentage by weight: less than or equal to 0.0040% of C, 0.10-0.15% of Si, 0.60-0.70% of Mn, 0.030-0.040 of Nb, 0.040-0.050% ofTi, 0.002-0.006% of N, 0.060-0.075% of P, 0-0.012% of S, 0.0005-0.0015% of B, 0.020-0.060% of Als, and the balance of Fe and inevitable impurities. The invention further provides the production methodof the steel plate. Relevant parameters such as the coiling temperature and the cooling speed are precisely controlled, the mechanical properties of the obtained steel plate are stable jointly, anisotropy is small, a coating is good in adhesion, the convex lug phenomenon is basically avoided after forming, the problem of secondary processing brittleness after forming is solved, and using and popularization prospects are good.