Preparation of Whisker-reinforced high thermal conductive AlN ceramic substance.

晶须增强高导热AlN陶瓷材料的制备

基本信息

批准号：
12650667
负责人：
HOTTA Noriyasu
金额：
$ 2.43万
依托单位：
Niigata University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650667/
关键词：
Aluminum nitride Whisker Fine powder Synthesis Sintering Rein-forced ceramics High thermal conductivity Ceramic substance

项目摘要

Fine aluminum nitride (AlN) powder and pure AlN whiskers were synthesized by ffloating-type fluidized-bed nitridation (continuous direct nitridation) of ultra-pure aluminum(Al) powder (99.99 purity, 20 μm of diameter). Synthesis mechanism of the AlN nitrides and their properties were investigated. Following, The AlN whiskers reinforced composite materials were prepared, and these properties were measured.High sinterable, pure and fine AlN (about 0.2 μm of diameter) powders were synthesized by the explosive nitridation of Al powder, and then pure AlN whiskers were produced on the reactor wall. White AlN whiskers having rough surface were synthesized by nitridatiuon of Al particles and nitrogen (N_2) gas. On the other hand, Transparent AlN whiskers having smooth surface were produced by using N_2-NH_3 gas mixture as a reactant gas. The white AlN whiskers having rough surface had good sinterability, however, the whiskers revealed poor resistance to oxidation and water. Transparent AlN whiskers having smooth surface had poor sinterability, and revealed high resistance to oxidation and water.Transparent, dense and high strength AlN ceraic was obtained by hot-pressing of the white AlN whiskers at 1900 for 120 min under 30 MPa in N_2 atmosphere. The thermal expansion coefficient of whisker-resin composite material was 3.44X10-5/K, which was similar to the comm on metals. The thermal conductivity of ones was 7.0 W/mK. The value was 35 times as much as that of ther resin. Whisker-powder composite AlN ceramic having high thermal conductivity of 157 W/mK, was produced by hot-pressing at 1900 for 120 min under 30 MPa in N_2 atmosphere.

通过粉状铝（Aln）粉末和纯Aln晶须通过超纯铝（Al）粉末（99.99纯度，20μm的直径为20μm）的粉状型氮（连续直接硝化）合成。研究了Aln氮化物及其特性的合成机制。随后，制备了Aln晶须增强的复合材料，并测量了这些特性。高污染，纯净和细胞（约0.2 µm的直径）粉末是通过Al粉末的爆炸性硝化合成的，然后在反应堆壁上产生纯Aln Whiskers。具有粗糙表面的白色Aln晶须由Al颗粒和氮气（N_2）气体的氮气合成。另一方面，使用N_2-NH_3气体混合物作为反应剂气体产生具有光滑表面的透明ALN晶须。具有粗糙表面的白色Aln晶须具有良好的骨骼性，但是，晶须显示出对氧化和水的抵抗力不佳。具有光滑表面的透明Aln晶须的污染性较差，并且揭示了对氧化和水的高度耐药性。通过在N_2大气中在30 MPa以下的1900分钟，在1900分钟以下的白色Aln晶须在N_2大气中的1900分钟，可获得透明，稠密和高强度ALN CERAIC。晶须 - 瑞星复合材料的热膨胀系数为3.44x10-5/k，其热导率为7.0 w/mk。该值是树脂的35倍。在N_2大气中，在30 MPa以下在30 MPa下，在1900分钟以30分钟的热压产生了高热电导率的高温电导率的晶须 - 粉状复合ALN陶瓷。