Preparation of High-porosity TiNi Alloys by SHS

1 Since ra as a new type of functional material, a shape memory alloy has been applied in many fields since the creation of the 60-hold generation after three years of research and development. With the development of science and society, conventional products that rely on processed materials such as sheet-and-bundle tubes as their main form, shape memory and super-elastic ramming effect have not been able to meet their increasingly high performance requirements. In addition to the superelasticity and shape memory properties of Yang alloys, there are also properties that dense materials do not have, such as low-density porosity, high permeability, etc. If these properties are combined with traditional materials, the development of materials may be possible. In particular, the development of composite materials, smart materials, biomedical materials, and damping and damping materials has injected new vitality.

Porous 1-jaw alloy is not a brand new material, but it is difficult to prepare high-porosity alloys. The traditional fusion casting method cannot obtain porous alloys, and powder metallurgy also makes it difficult to obtain niobium alloys with porosity greater than 3, and powder metallurgy. The method of taking 7 torn alloy is to rely on long-time high-temperature sintering, which not only consumes a lot of time and energy, but also requires precise control of the process. Self-propagating high-temperature synthesis is a kind of fast and convenient disjointed porous structure in the grid structure. This study selected this method to prepare high-porosity (1) alloy 2 raw materials and pure gold powders obtained by the test method. The green compact powders were uniformly mixed and pressed to a relative density of about 6 shocks. Self-propagating high-temperature synthesis under atmosphere, obtaining porous product. The product was cut and measured according to the method specified by the national standard. The density of the sample was measured. Porosity test The maximum pore size The relative permeability coefficient, ray diffraction, and phase composition of only 0 samples were recorded. SEM 3 observes the cross-section of the sample and the structure of the broken 1 structure and the composition of the analysis sample to confirm the full course of the 3 reaction. 结果 3 Results and analysis of the 51 reaction system. The porous 1 Y alloy sample still retains the shape of the original compact. The length after the reaction was about 7 more than before the reaction, and the osculation density was 3.15.13 The density of the alloy of the compacted D1 was 6.45 to reach a porosity of 1 μm greater than that of the original compaction, and the open porosity was 4 The number of bubbles measured by the bubble test method is 175,1;12. The porous material obtained by the Ming 5 Elixir has good hole connectivity, and the above properties are consistent with those specified in the national standard for sintered metal filter materials. Pieces can match The first one is more complicated than the sintered porous metal material. The size of the holes can be divided into two types: large hundreds of micrometers, which are through holes; the small ones are less than 10 and many are located in the large hole wall. The closed-cell pore wall is composed of micro-particle aggregates containing closed pores. The surface of the continuous and smooth inner surface of the powder-sintered material is determined to be different. The results of the scan of the 3 river components at the fracture are very uniform. , The component deviation is small, and the range of fluctuation is not more than 2. The analysis of the sample is used to identify the product. The main product of the product is the phase, only a small amount, and the reaction is performed during the process. The interval is only a few seconds up to 7:00. The powder diffusion sintering method for several tens of hours is rather insignificant, but the compounding reaction of the elemental powder 1 proceeds sufficiently. 81 The time during which the process is at a high temperature is short. If the artistic parameters are selected arbitrarily, the heat can be dissipated in time to avoid excessive temperature increase and excessive liquid phase is produced. The sintering shrinkage is minimized to obtain a high porosity with much higher pressure and porosity. alloy. In this test, the porosity of the product was increased from 33 to 5, which is difficult to achieve in the powder metallurgical sintering process.

Scanning Fan Xi 1 out of the porous material can be obtained by using elemental powder sintering, due to a group of compounding reaction will emit a lot of heat, resulting in pressure is also higher locally warming, the emergence of liquid phase, resulting in densification effect, so when sintering The heating rate must be controlled very slowly. It takes a long time to complete the sintering and homogenization. As a result, it is difficult to obtain a porous alloy with a high porosity. The 3 fertilizer technology is a rapid reaction processing technology. It mainly uses the reaction heat generated when the elements are combined, the synthesis of the material, and the system. This method can not only prepare dense and non-porous casters, but also can prepare the porous material and achieve it by adjusting the process parameters. The high-porosity porous 1 alloy is made by the book hall method, which utilizes its rapid synthesis process and the large difference in the mutual diffusion rate of the elements at high temperatures. According to data, the diffusion speed of 90 and Shi Dingchong in the Ding Chong is that at a high temperature of 4,000 times the diffusion speed, the atoms are near one-way migration, and the original part of the compaction in the compaction quickly becomes hollow. Into 1; atom and compound formation. Made 4 conclusions, shape memory alloy material, product composition is uniform, mainly by Yang Ding. In the presence of elemental phase, the porosity of the porous butadiene alloy prepared by the method can reach 5 Young, and the observed density is only the dense 1 claw, and the half of the alloy. Bubble test ftyGUlXnrl5Fm,RdJ1750 has better hole connectivity and permeation properties of metal materials and engineering, 1989; 18361 Isand1 capacity, move, do a prison metal materials and engineering, 19952428 edit Yi Yigang high temperature superconducting current limiter The demand for materials With the increase of power grid capacity, the development of fault current limiters is an urgent task. Superconducting fault current limiter 3, the design can be based on different concepts, but the design and application of a specific series of materials required to be used in the busbar The resistor-based current limiter with direct feeder position can be used as a simple and practical method to use the current high-temperature superconducting wire as the high-temperature superconducting fault current limiter 13, which has obvious advantages and is feasible. So far the most successful and most successful inductive superconducting flow restrictor, the choice of 221 cups of casting parameters of the material parameters, such as the tune after the transition, it also restricts the geometry of superconductors for commercialization, demand block Figure 021 æ´§, =. 122., 4 = 3 yang 30 yang 0 Normal state resistivity 4, = xin 03, 1 Choosing the center of the superconducting material asks stability. The design and application of specific needs to be solved 1 The key requirements of uniformity on the village material 2 To prevent the overheating and damage of the 1 50 ring, to ensure the stability of the device can operate 3 Fault 17 superconducting state of the ring can quickly restore; 4 in the superconducting state 1 The low AC loss; the actual device parameters and application areas are subject to the large-scale prototype operation, and the impact on the electromechanical process of the power system, it is necessary to determine the technical and economic benefits through the device application, so far the world, 1 in the development of Yunhan Jing Duo feed