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％。

公开(公告)号：US4923512A

公开(公告)日：1990-05-08

申请号：US334840

申请日：1989-04-07

申请人： Ed E. Timm ,  Douglas B. Schwarz

发明人： Ed E. Timm ,  Douglas B. Schwarz

IPC分类号： B22F3/15 ,  C22C29/08

CPC分类号： B22F3/156 ,  C22C29/08 ,  B22F2998/00 ,  B22F2998/10

摘要： Cobalt-bound tungsten carbide metal matrix composites having a unique microstructure are produced by consolidating partially sintered greenware under high pressures, e.g., 120,000 psi, at temperatures less than those used for conventional liquid phase sintering in a relatively short time, e.g., from less than one minute to less than about one hour. The composites have a binder phase which contains less than about 80 weight percent of the tungsten found in a composite prepared from the same or similar compositions via liquid phase sintering. These composites provide cutting tools with both toughness and wear resistance which exceed that of cutting tools made from the same or similar compositions via liquid phase sintering.

摘要翻译： 具有独特显微组织的钴结合碳化钨金属基复合材料是通过在较低压力（例如120,000psi）下，在比较短的时间内常规液相烧结所用温度小的温度 一分钟到不到一个小时。 复合材料具有粘结相，其含有通过液相烧结由相同或相似组合物制备的复合材料中发现的钨的小于约80重量％。 这些复合材料提供了具有韧性和耐磨性的切削刀具，其超过了通过液相烧结由相同或相似成分制成的切削刀具。