Carbothermal reduction and nitridation (CRN) of zircon ( ZrSiO4 ) permits obtaining diffbrent composites of oxides and nitrides such as ZrO2 -Si2N2O and ZrN - Si3N4. The effects tf technological parameters ( carb...Carbothermal reduction and nitridation (CRN) of zircon ( ZrSiO4 ) permits obtaining diffbrent composites of oxides and nitrides such as ZrO2 -Si2N2O and ZrN - Si3N4. The effects tf technological parameters ( carbon source, reaction temperature, and carbon con.tent ) on the reaction rate and product phase composition of CRN of zircon were investigated by TGA and XRD. The resuhs show that: (1) carbon source is an important factor for a rapid reaction, and actiwtted carbon is chosen as the carbon source considering the expect products and reaction rate ; ( 2 ) reaction tetnperature has vital effect on reaction rate and product. In, case of carbon content above 20% , the zircon phase and m-ZrO2 phase decrease with increasing temperature, while the ZF7N8O4 phase increases firstly and then decreases, and the ZrN phase increases continually; (3) different carbon contents result in different reaction products. The higher the carbon content, the lower the starting temperature for the CRN of zircon.展开更多
The aluminum nitride whiskers were synthesized by the nitridation of Al/AlN powders in a flowing nitrogen atmosphere. The whiskers were about 0. 5祄 in diameter and 10~20祄 in length, and they were straight and had sm...The aluminum nitride whiskers were synthesized by the nitridation of Al/AlN powders in a flowing nitrogen atmosphere. The whiskers were about 0. 5祄 in diameter and 10~20祄 in length, and they were straight and had smooth surfaces. The morphology of the whiskers were studied by means of SEM and TEM. The AlN whiskers were grown via vapor-solid (VS) mechanism.展开更多
基金the Natural Science Foundation of The Education Department of Henan Province,No.2011B430011the SRTP of Henan University of Science and Technology
文摘Carbothermal reduction and nitridation (CRN) of zircon ( ZrSiO4 ) permits obtaining diffbrent composites of oxides and nitrides such as ZrO2 -Si2N2O and ZrN - Si3N4. The effects tf technological parameters ( carbon source, reaction temperature, and carbon con.tent ) on the reaction rate and product phase composition of CRN of zircon were investigated by TGA and XRD. The resuhs show that: (1) carbon source is an important factor for a rapid reaction, and actiwtted carbon is chosen as the carbon source considering the expect products and reaction rate ; ( 2 ) reaction tetnperature has vital effect on reaction rate and product. In, case of carbon content above 20% , the zircon phase and m-ZrO2 phase decrease with increasing temperature, while the ZF7N8O4 phase increases firstly and then decreases, and the ZrN phase increases continually; (3) different carbon contents result in different reaction products. The higher the carbon content, the lower the starting temperature for the CRN of zircon.
文摘The aluminum nitride whiskers were synthesized by the nitridation of Al/AlN powders in a flowing nitrogen atmosphere. The whiskers were about 0. 5祄 in diameter and 10~20祄 in length, and they were straight and had smooth surfaces. The morphology of the whiskers were studied by means of SEM and TEM. The AlN whiskers were grown via vapor-solid (VS) mechanism.