制备工艺对六钛酸钾晶须隔热材料性能的影响

Effects of preparing process on properties of potassium hexatitanate whiskers insulating materials

以自合成的六钛酸钾晶须为主要原料,通过混料、成型和热处理等工艺制备出六钛酸钾晶须隔热材料,探讨了结合剂种类(无结合剂、PVA、黏土)、结合黏土加入量(质量分数分别为5%、7%和10%)、造孔剂锯末加入量(质量分数分别为3%、5%和7%)和六钛酸钾晶须的长径比(分别为10～20和50～60)对隔热材料的热导率、致密度和常温耐压强度的影响。结果表明:1)黏土结合试样的热导率比无结合剂试样和PVA结合试样的小,而常温耐压强度比无结合剂试样和PVA结合试样的大。2)黏土加入量对试样热导率的影响与热面温度相关:热面温度≤500℃时,试样热导率随黏土加入量的增加而减小,热面温度≥800℃时则随黏土加入量的增加而增大;随着黏土加入量的增加,试样的致密度和常温耐压强度均逐渐减小。3)随着锯末加入量的增加,试样的热导率、致密度和常温耐压强度均逐渐减小。4)采用高长径比晶须的试样具有较低的热导率和体积密度,较高的真气孔率和常温耐压强度。

Potassium hexatitanate whiskers insulating materials were prepared using self-synthesized potassium hexatitanate whiskers as main starting material by mixing,molding and heat treatment.Effects of binder kind（no binder,PVA,and clay）,clay additions（5%,7%,and 10%）,pore-forming sawdust additions（3%,5%,and 7%）,and length to diameter ratio of whiskers（10-20 and 50-60） on thermal conductivity,density,and cold crushing strength of the products were investigated.The results indicate that：（1）clay bonded specimen has lower thermal conductivity and higher CCS than specimen without binder and PVA bonded specimen;（2）if hot face temperature is lower than 500 ℃,thermal conductivity of specimen decreases with clay addition increasing;if hot face temperature is higher than 800 ℃,thermal conductivity of specimen increases with clay addition increasing;density and CCS of specimens decrease gradually with sawdust addition increasing;（3）thermal conductivity,density,and CCS decrease with sawdust addition increasing;（4）the specimen with higher length to diameter ratio exhibits lower thermal conductivity and bulk density,and higher true porosity and CCS.