High strength, low thermal conductivity and collapsible of Y2O3-stablized HfO2 crystalline fibrous membranes

HfO2 is an important high temperature resistant material, which has a high melting point (2810 degrees C), 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, flexibility and further can be processed into a variety of product forms. In this paper, high strength HfO2 crystalline nanofibers were prepared through self-synthesis polyacetylcatonahafnium (PAHf) with electrospinning method. Phase variation process was discussed in detail, and the HfO2 fibers that use Y2O3 as stabilizer with phase stability were prepared finally. The fibers were composed of nanocrystals with good flexibility even folded in half, tensile strength of 1.6 MPa @ 1000 degrees C and can lifting up 1288 times its own weight, low density around 35 mg/cm(3). The thermal conductivity was stable around 26 mW/(m.K) @ 1200 degrees C and the temperature can be cooled from 1200 degrees C to 396 degrees C after 180 s through 7 mm fibrous membranes. And after treated at 1200 degrees C for 5 h, the fibrous membranes also maintain high strength and good flexibility. By this kind of precursor method, high strength oxide fibers can be obtained, which has a wide application prospect in field of high temperature thermal protection.