摘要:
Disclosed are a Fe—Ni—P-RE multicomponent alloy plating layer, and electrodeposition preparation method and application thereof. An alloy plating layer obtained via electrodeposition contains elements of Fe, Ni, P and RE, the mass percentage of Fe being 20%-65%, the mass percentage of Ni being 25%-70%, the combined mass percentage of Fe and Ni being 65%-90%, the mass percentage of RE being 2%-25%, and the balance being P. The plating solution mainly contains the following components: ferrous salt, nickel salt, NaH2PO2, RECl3, H3BO3 and Na3C6H5O7. A multicomponent alloy plating layer of different components can be obtained by adjusting the main salt and complexing agent in the plating solution and by adjusting the process. The present invention realizes controllable adjustment to the components of the obtained plating layer while saving costs, and further improves indexes such as the thermal expansion coefficient, electrical property, magnetic property, etc., and is very suitable for applications in the field of micro-electronics.
摘要:
The present invention relates to a cold-rolling method for cold-rolling a wrought Mg alloy with a weak or non-basal texture as well as a cold-rolled sheet, the method comprising the steps of: pre-treating a billet of the wrought Mg alloy with a weak or non-basal texture, and then cold rolling it; wherein the weak or non-basal texture plane of said billet is selected as a rolling plane, and the rolling direction is parallel to the rolling plane; and said billet is cold rolled at room temperature to a sheet or foil with a thickness of 0.1 to 100 mm, wherein single-pass or multi-pass rolling is used, and the cold rolling is followed by an annealing at 200 to 400° C. for 10 min to 48 h.
摘要:
The invention provides Al2O3 dispersion-strengthened Ti2AlN composites, wherein Ti2AlN matrix and Al2O3 strengthening phase both are reactively formed in situ. The volume fraction of Al2O3 is 5% to 50%; the particle size of Al2O3 ranges from 500 nm to 2 μm, with the mean size of Al2O3 particles about 0.8 μm to 1.2 μm; the shape of Ti2AlN grain is plate-like about 80 nm to 120 nm thick and 0.5 μm to 2 μm long. The composites exhibit excellent deformability at high temperature under compression and flexure stresses, and possess excellent oxidation resistance at 1100° C. to 1350° C. for long time (100 h). The composites show typical metallic conductor behavior and the electrical resistivity at room temperature is 0.3 to 0.8 μΩ·m. The invention also provides a method for preparing the same: First, nanoparticles in Ti—Al binary system were prepared in continuous way by hydrogen plasma-metal reaction (HPMR) using Ti—Al alloy rods with Al content 20% to 60% by atom, or pure Al rods and pure Ti rods. The atmosphere used in HPMR is the mixture atmosphere of nitrogen-containing gas, H2 and Ar, with total pressure of 0.8 to 1.2 atm, wherein volume ratio of H2 and Ar is 1:0.8-1.2, and volume fraction of nitrogen-containing gas is 0 to about 20%. Second, the nanoparticles were compacted by vacuum hot pressing at temperature of 800° C. to 1200° C., pressure of 40 MPa to 60 MPa, time of 4 h to 6 h, and vacuum of 2×10−2 Pa to 5×10−3 Pa.
摘要:
A method for preparing nanometer MAX phase ceramic powder or slurry having a laminated structure by means of ball milling and regulating the oxygen content of the powder. Micron-sized MAX phase ceramic coarse powder is adopted as a raw material, during ball milling, a gas or a liquid-state gas having a special effect is introduced into a ball milling tank, and by means of multi-dimensional functions and regulation such as ball milling parameters and gas reaction, the nanometer laminated MAX phase ceramic powder or the slurry containing the component is obtained. The surface components and the activated state of the powder are regulated while the particle size adjustment control of the powder is realized.
摘要:
An efficient method for preparing a highly-directional highly-dense two-dimensional material film. The method comprises: using a circular tube with a smooth inner surface as a casting mold; and pouring a solution containing a two-dimensional material into the mold when the mold rotates at high speed in a circumferential direction, wherein the solution is uniformly coated on the inner surface of the mold by centrifugal force, the centrifugal rotation generating a shearing force that causes the two-dimensional material to be directionally and regularly arranged layer upon layer in a circumferential direction in the solution, and, the centrifugal force facilitates highly-dense accumulation of the two-dimensional material, thereby obtaining a highly-directional highly-dense two-dimensional material film. The method is applicable in the preparation of a variety of two-dimensional materials such as graphene, a composite material film thereof, and a laminated heterostructure film, and greatly improves electrical, thermal, and mechanical properties of a film.
摘要:
Provided in the present application are a rare-earth microalloyed steel and a control process. The steel has a special microstructure, and the microstructure comprises a rare earth-rich nanocluster having a diameter of 1-50 nm. The nanocluster has the same crystal structure type as a matrix. The rare earth-rich nanocluster inhibits the segregation of the elements S, P and As on a grain boundary, and obviously improves the fatigue life of the steel. In addition, a rare-earth solid solution also directly affects a phase change dynamics process so that the diffusion-type phase change starting temperature in the steel changes at least to 2° C., and even changes to 40-60° C. in some kinds of steel, thereby greatly improving the mechanical properties thereof, and providing a foundation for the development of more kinds of high-performance steel.
摘要:
The present invention relates to the field of MAX-phase ceramic-based composites, specifically to a short-fiber-reinforced oriented MAX-phase ceramic-based composite and a preparation method therefor. By using a new process with a fiber, a nano lamellar MAX-phase ceramic powder, other additives, etc., for preparing a fiber-reinforced MAX-phase ceramic-based composite, a novel ternary composite is prepared, wherein a matrix is composed of a highly oriented lamellar MAX-phase ceramic, the fiber is distributed parallel to the lamellar MAX-phase ceramic in an axial direction, and a granulate ceramic phase enhancement phase is dispersed in the matrix. Thus, the problems of a MAX-phase ceramic-based composite matrix material prepared by an existing method, such as coarse grains, multiple internal defects and a low strength, and a poor fracture toughness; and a reaction sintering temperature being too high such that fibers are chemically and physically damaged in a substrate, resulting in performance degradation, are solved. Fibers prepared by the method are suitable for large-scale industrial preparation and have properties that are far superior to those of any existing known fiber MAX-phase composite.
摘要:
A method for improving mechanical properties by changing a gradient nanotwinned structure of metallic materials is the technical field of nanostructured metallic materials. The method uses the inherent principles of microstructure and mechanical properties of metallic materials to improve materials mechanical properties. The metallic materials has a gradient nanotwinned structure. The principles of microstructure and mechanical properties of the metallic materials mean that the mechanical properties of the metallic materials are adjusted by changing the structural gradient scale of the nanotwinned structure. The method combines two strengthening methods of nanotwins and gradient structure, and can obviously improve the mechanical properties of the metallic materials. For pure copper materials of the gradient nanotwinned structure prepared by an electrodeposition technology: the yield strength is 481±15 MPa, the tensile strength is 520±12 MPa, the uniform elongation can be 7±0.5%, and the elongation to failure can be 11.7±1.3%.
摘要:
The present invention aims at providing a small-diameter wire/rod/tube ultrasonic detector with an end blind area and an automatic ultrasonic nondestructive detecting system, wherein a sealing cover of the ultrasonic detector is located on a water storage device; an annular array unit mounting rack and a water pump are fixed in the water storage device, and an annular array detecting unit is connected to the annular array unit mounting rack; the water pump is connected to an input end of water circulation input and output; a sensor is mounted in one side of the sealing cover in which a detected material is allowed to enter; the annular array detecting unit comprises an outer ring part and an inner ring part, and the outer ring part and the inner ring part are connected into a whole by means of a wire inlet side end cover and a wire outlet side end cover; the outer ring part consists of an outer ring substrate and an outer ring arraying probe, and the inner ring part consists of an inner ring inner core and an inner ring inner core locking ring. The ultrasonic detector in the present invention has unique “acoustic eye” structure characteristics, changes the mode of ultrasonic waves entering the detected material, and can effectively eliminate the end detection blind area of the wire/rod/tube.
摘要:
A constructing-and-forging method for preparing homogenized forged pieces comprises: preparing preformed billets: cutting off a plurality of continuous casting billets, milling and smoothing surfaces of the billets to be welded, performing vacuum plasma cleaning operation to the surfaces to be welded, stacking the plurality of billets and sealing around the surfaces in a vacuum chamber by electron beam welding; forge-welding and homogenizing the preformed billets: heating the preformed billets to a certain temperature in a heating furnace and taking the heated preformed billets out of the heating furnace, forging the preformed billets by a hydraulic press, then using three-dimensional forging to disperse the welded surfaces such that composition, structure and inclusion of the interface areas are at the same level as those of the bodies of the billets. Cheap continuous casting billets are stacked and forge welded.