Aluminum foam is obtained by mixing aluminum alloy powder with a substance separated during heating and gasification. It has the characteristics of light weight, high porosity and high specific surface area. It has both the characteristics of metal materials and foam, and has strong impact resistance, high specific strength, high temperature resistance, strong fire resistance, and also has strong electromagnetic shielding and filtering properties. Today, we will introduce the seven performance advantages of aluminum foam testing in detail.
1. Inspection of aluminum foam – structural performance analysis
The biggest structural feature of aluminum foam is that it has a large number of pores inside, which makes it light in weight and high in specific strength. Because of these characteristics, aluminum foam becomes the best sandwich filler for sandwich composite panels, which greatly improves the deformation mode of the composite material under load, so that its bending resistance, compressive strength, and noise absorption ability are improved. effective improvement. Compared with the traditional honeycomb sandwich material, the foamed aluminum material effectively reduces the cost and overcomes the disadvantage of the anisotropy of the honeycomb sandwich material.
2. Detection of aluminum foam material – analysis of energy absorption performance
The process from force to compression of foam material is divided into three stages, the first stage is elastic deformation stage. After being stressed, the internal pores of the foamed aluminum material undergo recoverable elastic deformation. The second stage is the shaping platform stage. When the mechanical strength of the foamed aluminum material reaches an irrecoverable level, it enters the shaping deformation stage. At this time, the internal pores undergo deformation such as yielding and creep, and finally collapse completely. When the degree of collapse reaches the contact between the opposite pore walls, it enters the third stage: the densification stage. Therefore, after the aluminum foam is subjected to pressure, it undergoes a unique compression deformation behavior. In the process, the pressure is converted into the ability of foam deformation, which effectively absorbs the energy of the impact force.
3. Detection of aluminum foam – shock absorption performance analysis
Foamed aluminum has high damping properties, 5 to 10 times that of pure aluminum. This characteristic is related to the porosity, pore size and load-strain amplitude of the aluminum foam itself. The higher the porosity, the smaller the pore size and the larger the load-strain amplitude, the better the damping of the aluminum foam.
When the foamed aluminum material is subjected to external stress, due to the uneven pores, the strain force distribution is also uneven, so that the normal strain force is converted into shear stress, which consumes the external stress and converts it into thermal energy inside the foamed aluminum material . According to this characteristic of foamed aluminum material, foamed aluminum material becomes an excellent shock absorbing material. Such as car bumpers, landing gear of spaceships, etc.
4. Aluminum foam testing – sound absorption performance analysis
The unique pore structure of aluminum foam material makes it have good sound absorption performance. When the sound passes through the pore, it causes the resonance of the sound in the pore, and the friction with the pore wall generates heat energy, and the heat energy is dissipated through the aluminum, so the pore structure of the foamed aluminum material effectively absorbs the noise. The sound absorption performance of foamed aluminum material increases with the increase of porosity, the decrease of pore size and the increase of material thickness. According to the sound absorption properties of aluminum foam, it is widely used in radio recording studios and automatic office equipment.
5. Detection of aluminum foam – analysis of electromagnetic shielding performance
The research and testing show that the foamed aluminum material has good electromagnetic shielding performance. When the high-frequency magnetic field passes through the foam, an eddy current magnetic field is generated inside the foam, which cancels the original magnetic field. According to this performance, the foamed aluminum material is applied to the electronic equipment room and electronic equipment,
In shielding materials for electronic equipment.
6. Detection of aluminum foam material – analysis of heat exchange and thermal insulation performance
Because the aluminum foam material contains a large number of air bubbles with small heat transfer ability, its thermal conductivity is not as high as that of aluminum, but it is much better than that of foamed plastics. Its thermal conductivity is affected by porosity, and the higher the porosity, the worse the thermal conductivity. Under natural convection conditions, heat is dissipated by heat exchange between the gas or liquid and the pore walls. This makes aluminum foam a good heat exchange or heat dissipation material. For example, a deicing device is installed in front of the aircraft wing, and the heated gas or antifreeze is ejected from the foamed aluminum material to achieve the purpose of deicing.
7. Aluminum foam detection – filtration performance analysis
Due to the permeability of aluminum foam, it can be used as a good filter material in biological and chemical fields. The pores in the aluminum foam material have a good filtering and separation effect on gases or liquids, and can also filter air solids.