Study On Heat-protection Composites Of Glass/phenol Aldehyde Modifies With Nano-iron Particle

Many powerful military nations are interesting in stealth materials recently, because it is as an efficient and economical method to make weapon concealing under radar detection. But the traditional stealth materials are usually sprayed on the surface of product which makes it many deficiencies such as low application temperature. So, they couldn't meet the requirement of the weapons like missile, which will generate great heat during its flying. Considering the nano-iron particle to be a kind of new-type absorbing material and enhancing material, combining it to heat-protection shell of missile can not only improve its physical and chemical property but also design missile shell with wide band radar absorbing property and simple structure. So in this paper two style nano-iron particle with different surface state and grains size were synthesized by using non-water micro-emulsion method, and they were used to modified glass/ phenol aldehyde heat-protect shell material as filler .At the same time,the effect of surface property, grain size and filling content of the nano-iron particles to physical, mechanical and absorbing property of the composite material were studied. The results are as follows:1. When the surface of particle was MP , with the increasing of grain size ,the elastic modulus of modified composites increases initially and then declines,,and the maximum appears at 100nm, up to 171.9MPa and 15.9GPa, respectively, and the bend strength, interlayer strength and linear erosion rate decreased.,the changes of compression strength, thermal conductivity and specific heat capacity were not too much. When the surface of particle was ATPU, the tensile strength, bend strength, interlayer strength and elastic modulus decreased, linear erosion rate increases, compression strength increases initially and declines later and the changes of thermal conductivity and specific heat capacity were still not too much.2. With the increasing of particle content, the density of modified composites increases, the tensile strength increases initially and then declined . And the maximum of 171.9MPa appears at content of 5% . Bend strength, elastic modulus and compression strength of modified composites increase,, but its interlayer strength, linear erosion rate and thermal conductivity decrease. 3. With the decreasing of grain size, the dielectric constant of modified composites increases appreciably, and resonance phenomenon appear in X band, which moved to higher values. With the increasing of particle content . The dielectric constant of composites also increased. The strength of resonance hump on X wave range increased and moved to higher values appreciably. The computer simulation and real testing of plate specimen indicated that filling appropriate amount of iron nano-particle in composites would realize part stealth property. When the content is 5%, the microwave of modified composites will decrease -3 dB to 5dB in the range of 8GHz～16 GHz, which indicate the feasibility and engineering practicality of our structure-function integration design of stealth- heat-protection composites.