کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
830640 | 1470357 | 2012 | 5 صفحه PDF | دانلود رایگان |
Silicone resin (SR) processed Si3N4 porous ceramics with high and hierarchical porosity were prepared by adding naphthalene as a pore-forming agent via pressureless sintering technique. The porosity of the obtained Si3N4 porous ceramics is 40 ∼ 71% with pores sizes ranging 0.1 ∼ 1.0 μm, 5 ∼ 30 μm and 50 ∼ 200 μm, which is determined by the pyrolysis of SR, partial sintering of Si3N4, and the volatilization of naphthalene, respectively. The bending strength is 6.8 ∼ 80 MPa and the dielectric constant is 2.29 ∼ 4.84. The results suggest that the hierarchical structure is responsible for a low dielectric constant with excellent mechanical property of the Si3N4 porous ceramics, making this material a good candidate for electromagnetic radome application.
► Si3N4 ceramics with high and hierarchical porosity are low temperature precessed.
► Si resin is as a binder and pore forming agent, offering a strength enhancement.
► The hierarchical structure is good for low dielectric constant and high strength.
Journal: Materials & Design - Volume 40, September 2012, Pages 562–566