High strength, low thermal conductivity and collapsible of Y_2O_3-stablized HfO_2 crystalline fbrous membranes

摘要

HfO_2 is an important high temperature resistant material, which has a high melting point (2810 ℃), good chemical stability and high thermal radiation. Fibrous material has some advantages for heavy refractory matter, such as large aspect ratio, light weight, more energy saving, fexibility and further can be processed into a variety of product forms. In this paper, high strength HfO_2 crystalline nanofbers were prepared through self-synthesis polyacetylcatonahafnium (PAHf) with electrospinning method. Phase variation process was discussed in detail, and the HfO_2 fbers that use Y_2O_3 as stabilizer with phase stability were prepared fnally. The fbers were composed of nanocrystals with good fexibility even folded in half, tensile strength of 1.6 MPa @ 1000 ℃ and can lifting up 1288 times its own weight, low density around 35 mg/cm3. The thermal conductivity was stable around 26 mW/(m-K) @ 1200 ℃ and the temperature can be cooled from 1200 ℃ to 396 ℃ after 180 s through 7 mm fbrous membranes. And after treated at 1200 ℃ for 5 h, the fbrous membranes also maintain high strength and good fexibility. By this kind of precursor method, high strength oxide fbers can be obtained, which has a wide application prospect in feld of high temperature thermal protection.