工业级氢氧化铝制备高韧性氧化铝陶瓷及机理分析

Preparation and Analysis of Mechanism of the High Fracture Toughness Alumina Ceramics with the Cheap Commercial Aluminum Hydroxide

采用价格低廉的工业氢氧化铝粉为初始原料,通过球磨介质磨耗向氢氧化铝中引入高纯α-Al2O3作为晶种,通过热压烧结,氧化铝晶粒原位异向生长成长柱状和板状的晶粒,从而在瓷体的断裂过程中产生裂纹桥接、偏转和晶粒拔出的增韧机制,使制备出的氧化铝陶瓷断裂韧性得到了显著的提高。在热压烧结压力为30MPa、1600℃烧结2h制备的氧化铝烧结体,其抗弯强度和断裂韧性分别为550MPa、6.08MPa.m1/2。

The preparation of the high commercial aluminum hydroxide as the temperature-calcination of the aluminum alumina ball medium through grinding. fracture toughness alumina ceramics started with the cheap raw materials. The or-alumina powder was gained by low- hydroxide with seeds, which were introduced by high purity The alumina powder was hot-pressed sintered and the high fracture toughness alumina ceramics with elongated grains were obtained. The anisotropic grains, such as elongated and platelet grains were found in the calcined ceramics, which could greatly increase fracture toughness of alumina by producing crack bridging, crack deflection and grain pull-out. The fracture toughness and fracture strength of alumina reached 6.08 MPa · m^1/2 and 550 MPa respectively when it was hot-pressed at 1600℃ for 2 h under 30 MPa.