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。

公开(公告)号：US5160508A

公开(公告)日：1992-11-03

申请号：US826315

申请日：1992-01-24

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： C04B35/593 ,  C04B35/645 ,  C04B35/80

CPC分类号： C04B35/593 ,  C04B35/645 ,  C04B35/806

摘要： A process for preparing a self-reinforced silicon nitride ceramic body of high fracture toughness comprising hot-pressing a powder 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 densificaton 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 percent, 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，致密化助剂例如氧化钠，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，基于陶瓷的总重量，至多5.0重量％的氮化铝或氮化硼。 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。

公开(公告)号：US5021372A

公开(公告)日：1991-06-04

申请号：US398801

申请日：1989-08-25

申请人： Aleksander J. Pyzik ,  Douglas B. Schwarz ,  Harold E. Rossow ,  Donald R. Beaman ,  Barbara M. Pyzik ,  William J. Dubensky

发明人： Aleksander J. Pyzik ,  Douglas B. Schwarz ,  Harold E. Rossow ,  Donald R. Beaman ,  Barbara M. Pyzik ,  William J. Dubensky

IPC分类号： 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 powder 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 percent, based upon total weight of the ceramic, of aluminum nitride or boron nitride.

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，致密化助剂例如氧化钠，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，基于陶瓷的总重量，至多5.0重量％的氮化铝或氮化硼。

公开(公告)号：US4919689A

公开(公告)日：1990-04-24

申请号：US290720

申请日：1989-02-28

申请人： Aleksander J. Pyzik ,  Douglas B. Schwarz ,  William J. Dubensky ,  Donald R. Beaman

发明人： Aleksander J. Pyzik ,  Douglas B. Schwarz ,  William J. Dubensky ,  Donald R. Beaman

IPC分类号： C04B35/593 ,  C04B35/645 ,  C04B35/80

CPC分类号： C04B35/806 ,  C04B35/593 ,  C04B35/645

摘要： A process for preparing a self-reinforced silicon nitride ceramic body of high fracture toughness comprising hot-pressing a powder mixture containing silicon nitride, magnesium oxide, yttrium oxide and calcium oxide 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 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 magnesium oxide, yttrium oxide, calcium oxide, and silica in a total amount not greater than about 35 weight percent; and not greater than about 10 weight percent of the total weight as other phases.

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，其包括在使得致密化和原位形成β-氮化硅的条件下热压含有氮化硅，氧化镁，氧化钇和氧化钙的粉末混合物 发生具有高纵横比的晶须。 公开了一种具有高断裂韧性的新型氮化硅陶瓷，其包括β-硅氮化物结晶相，其中该相的至少约20体积％为具有至少约2.5的平均纵横比的晶须形式; 含有不大于约35重量％的氧化镁，氧化钇，氧化钙和二氧化硅的玻璃状第二相; 并且不大于作为其它相的总重量的约10重量％。

公开(公告)号：US4883776A

公开(公告)日：1989-11-28

申请号：US148748

申请日：1988-01-27

申请人： Aleksander J. Pyzik ,  William J. Dubensky ,  Douglas B. Schwarz ,  Donald R. Beaman

发明人： Aleksander J. Pyzik ,  William J. Dubensky ,  Douglas B. Schwarz ,  Donald R. Beaman

IPC分类号： C04B35/584 ,  C04B35/593 ,  C04B35/645 ,  C04B35/80 ,  C04B35/81

CPC分类号： C04B35/806 ,  C04B35/593 ,  C04B35/645

摘要： A process for preparing a self-reinforced silicon nitride ceramic body of high fracture toughness comprising hot-pressing a powder mixture containing silicon nitride, magnesium oxide, yttrium oxide and calcium oxide 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 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 magnesium oxide, yttrium oxide, calcium oxide, and silica in a total amount not greater than about 35 weight percent; and not greater than about 10 weight percent of the total weight as other phases.

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，其包括在使得致密化和原位形成β-氮化硅的条件下热压含有氮化硅，氧化镁，氧化钇和氧化钙的粉末混合物 发生具有高纵横比的晶须。 公开了一种具有高断裂韧性的新型氮化硅陶瓷，其包括β-硅氮化物结晶相，其中该相的至少约20体积％为具有至少约2.5的平均纵横比的晶须形式; 含有不大于约35重量％的氧化镁，氧化钇，氧化钙和二氧化硅的玻璃状第二相; 并且不大于作为其它相的总重量的约10重量％。