1、1The multifunctional properties and the application of the ultra light porous metal materialsAbstract. Material technology is the important foundation of the development of science and technology， and the materials technology innovation will promote the changes of the production and the life. The ap
2、pearance of the porous metal opens up a new field and the development goals for the material technology， whose excellent functional characteristics make it different from the traditional materials， and it has been applied in many fields. With the development of the technology， people are no longer s
3、atisfied with the light aroma， but pay more attention to the composite application value of the functional properties. Key words： Lightweight materials； porous metal； functional characteristics； applied range 1. The multi-functional properties of the ultra light porous metal materials The so-called
4、porous metal material is a new material with the extensive distribution of holes in a metal skeleton. The diversified space changes the original properties of the metal 2materials， so as to form a composite functional character， and is a kind of generalized damping material. And the ultra light poro
5、us metal has more excellent performances， whose multifunctional properties are as follows： 1-1. Low density Most of the structures of the porous materials are the holes， which also mean that the quality is greatly reduced. Especially the void ratio of the ultra light materials can reach more than 80
6、%， or even 99%. This means that there is a huge difference in the density of the basic metal materials， such as the aluminum foam. If the porosity reaches 90%， the density is reduced to 25% of the water， and its density is much lower than the aluminum metal. 1-2. Strong toughness In the experiment，
7、the pressure and stress of the porous metal， and the strain stress curve in the stage of plastic deformation is basically unchanged， and in the deformation it transforms into a large amount of the plastic energy， and the heat is consumed， which is a good crash-proof material. At the same time it als
8、o has strong toughness， which can control the serious consequences of the instant destroy when the porous material exists fractures. 31-3. Good heat dissipation effect The porous metal can be very good heat dissipation under forced convection conditions， and the specific gap setting can help the mat
9、erial to create the fixed gas flow， so as to help radiating of the structure of the material and its package. At the same time， the high void lattice structure can realize the double effects of radiating and bearing， and can help the electronic equipment， the aerospace equipment and so on to realize
10、 the double effects of the radiation and protection. In addition， the application of the porous metal materials in the industry also demonstrates the performance of the composite materials. The surface area ratio is big， which can be used in the heat exchanger. Use the holes to realize the direction
11、al flow of the liquid or gas， to realize the exchange of the heat with the metal material， to reach the convection effect and heat dissipation， and to achieve the refrigeration or heating effect. The porous material has an important significance for the design and production of the compact heat sink
12、. Especially in the field of microelectronics， the radiator made of ultra light porous metals can help the computer or the integrated circuits with heat dissipation. Secondly， the porous material can help to improve the efficiency of chemical reactions with 4high porosity. We can make the porous mat
13、erials into the catalyst carriers， to increase the contact area of the catalyst and the reaction gas or liquid， thereby improving the efficiency of chemical reactions. For example， the corrosion resistance metal material has the characteristics of corrosion resistance， heat conduction， and high poro
14、sity， which can replace part of the ceramic materials. Finally， the porous metal material can be applied with battery or similar reactions as electrodes， which can greatly reduce the weight of the electrodes. For example， the porous lead material can be used to replace the tin plates as the reaction
15、 carriers of the lead acid battery， which can increase the reaction areas and also reduce the weight. 2-2. The field of national defense The porous metal material is the good aerospace material， and the quality of the spacecraft must be reduced to the greatest extent in the field of space technology
16、， so the light characteristics of the porous materials have a play， and at the same time， the complex characteristics of the porous materials are reflected. For example， the aircraft lifting made of the porous materials can improve the buffer capacity and lower the weight at the same time. In the ae
17、rospace 5design， the material is one of the most basic questions. The application prospects of the porous materials are not limited in the manufacturing of the space shuttles， and it can be expanded into all fields of the aeronautics and astronautics. For example， for the bearing parts of the satell
18、ites， using porous materials to replace the traditional materials will not only reduce the weight but also increase the impact resistance performance. At the same time， the porous material can be used as the dye sprayer of the rockets， to make the dye outflow through the voids， and the atomization e
19、ffect will be obviously better， so as to enhance the efficiency of the dye combustion. In the field of conventional military， the vibration or noise， heat and others of some military weapons themselves are easy to be detected， which also reduces the weapons survival and stability， and also easily le
20、ad to reduce the operating life of the engine or components. In these areas we can make use of the porous metal materials to fully help the weapons with the sound absorption and the wave absorption to reduce the noise and increase the strength of the parts， in order to improve the stability and viab
21、ility of the weapons. 2-3. The field of environmental protection 6The problem of environmental pollution at present caused by the economic development has been very sharp， and the noise， air pollution， water pollution have become the three largest factors of pollution. The porous metal material has
22、a good controlling effect on the noise. For example， in the train， automobile， mechanical systems it can help the systems to eliminate the noise caused by vibration. The damping properties can transform effectively the vibration into the heat and can effectively reduce noise pollution. In addition，
23、the porous materials can also be used as noise absorbing materials， and the acoustic wave compresses the air flow in the pores of the porous metals， during which time the friction and the turbulence will consume the wave energy， thus reducing the energy of the noise expansion to the external， to ach
24、ieve the purpose of noise reduction. Sound insulation boards can be made from such porous metal materials， which can be used to wrap the noise sources， so as to achieve the purpose of reducing the noise pollution. In the construction industry， some structures must be of light weight and high strengt
25、h， and also should have a certain degree of flame-retardant properties. At this time the porous materials can be used as the core material of this type of 7materials， and the material is composed of the porous metal materials directly or combined with other materials. Such materials in the construct
26、ion not only can play the role of supporting the structures， but also play a role in beautifying the appearance， and suppressing the noise etc. In addition， the porous metal can be used as the elevator cabin. In addition to the better strength， it can reduce the weight so as to achieve the effect of
27、 energy saving， and it also has the flame retardant property. Finally， the porous metal material can be used for the treatment of air and water， which can be used as the reaction carrier to increase the surface contact areas in the air and water purification and treatment. The structure optimization
28、 and the material selection of the ultra light porous metal can make it be applied to the secondary treatment of the air and water， in order to improve the processing efficiency. 3. Conclusion The ultra light porous metal materials will reflect the characteristics different from the common metal mat
29、erials because of the change of its microscopic structures， and its characteristics of light weight， high strength and thermal conductivity can obtain better application value in different application fields. Along with the development of the material 8technology and the improvement of manufacturing
30、 technology， the porous metal materials will replace the traditional metallic materials in many fields， thus changing the production and the life. References： 1 Lin Yunming. Discussion on the application of the porous metal materials J， Science and Technology Innovation Herald， 2009， （9） 2 Zhou Zhao
31、yao， Wu Zhengqiang. Research on the gap of the sintered porous metal J， Powder metallurgy industry， 2005， 15 （4） 3 Yang Xuejuan， Liu Ying， Li Meng， Tu Mingjing. Preparation and application of the porous metal materials J， Journal of materials， 2007 （S1） 4 Zhao Guiping， Lu Tianjian. The dynamic respo
32、nse of the porous metal clamp plates under impact load J， Chinese Journal of theoretical and applied mechanics， 2008 （02） 5 Hao Gangling， Han Fusheng， Li Weidong， Bai Shaomin， Yang Nengxun. Analysis of the preparation process and the performances of the porous metal materials J， Journal of Yanan University （NATURAL SCIENCE EDITION） ， 2008 （02）
