专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

12. 发明授权

US5118645A Self-reinforced silicon nitride ceramic of high fracture toughness and a method of preparing the same 失效
$Self-reinforced silicon nitride ceramic of high fracture toughness and a method of preparing the same$
标题翻译：具有高断裂韧性的自增强氮化硅陶瓷及其制备方法
公开(公告)号：US5118645A
公开(公告)日：1992-06-02
申请号：US572823
申请日：1990-08-24
申请人： Aleksander J. Pyzik , Harold E. Rossow , Douglas B. Schwarz , Donald R. Beaman , Barbara M. Pyzik , William J. Dubensky
发明人： Aleksander J. Pyzik , Harold E. Rossow , Douglas B. Schwarz , Donald R. Beaman , Barbara M. Pyzik , William J. Dubensky
IPC分类号： B23P15/28 , C04B35/584 , C04B35/593 , C04B35/645 , C04B35/80
CPC分类号： C04B35/645 , C04B35/593 , C04B35/806
摘要： A process for preparing a self-reinforced silicon nitride ceramic body of high fracture toughness comprising hot-pressing a powdcer mixture containing silicon nitride, a densification aid such as sodium oxide, a conversion aid such as lanthanum oxide and a compound, such as gallium oxide, which enhances growth of .beta.-silicon nitride whiskers-under conditions such that densification and the in situ formation of .beta.-silicon nitride whiskers having a high aspect ratio occur. A novel silicon nitride ceramic of high fracture toughness and high fracture strength is disclosed comprising a .beta.-silicon nitride crystalline phase wherein at least about 20 volume percent of the phase is in the form of whiskers having an average aspect ratio of at least about 2.5; a glassy second phase containing the densification aid, the conversion aid, the compound which enhances growth of .beta.-silicon nitride whiskers, and an amount of silica; and not greater than about 10 weight percent of the total weight as other phases. The glassy phase may also include a minor amount, e.g., up to 5.0 weight percentg, based upon total weight of the ceramic, of aluminum nitride or boron nitride. The glassy phase optionally includes an amount of a secondary reinforcing material such as silicon carbide whiskers.
摘要翻译：一种制备高断裂韧性的自增强氮化硅陶瓷体的方法，包括热压含有氮化硅的粉末混合物，致密化助剂如氧化钠，转化助剂如氧化镧和化合物如氧化镓，其增强了β-硅氮化物晶须的生长 - 在使得具有高纵横比的β-硅氮化物晶须的致密化和原位形成的条件下。公开了一种具有高断裂韧性和高断裂强度的新型氮化硅陶瓷，其包括β-氮化硅结晶相，其中该相的至少约20体积百分数为晶须的形式，其平均纵横比为至少约2.5; 含有致密化助剂的玻璃质第二相，转化助剂，增强β-硅氮化物晶须生长的化合物和一定量的二氧化硅; 并且不大于作为其它相的总重量的约10重量％。玻璃相还可以包括少量，例如，至多5.0重量％，基于陶瓷的总重量，氮化铝或氮化硼。玻璃相任选地包括一定量的第二增强材料，例如碳化硅晶须。

IPRDB

热门服务

关于我们

友情链接

联系方式