Self-reinforced silicon nitride ceramic of high fracture toughness and a
method of preparing the same
    1.
    发明授权
    Self-reinforced silicon nitride ceramic of high fracture toughness and a method of preparing the same 失效
    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

    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。

    Self-reinforced silicon nitride ceramic of high fracture toughness
    2.
    发明授权
    Self-reinforced silicon nitride ceramic of high fracture toughness 失效
    自增强氮化硅陶瓷具有高断裂韧性

    公开(公告)号:US5160508A

    公开(公告)日:1992-11-03

    申请号:US826315

    申请日:1992-01-24

    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。

    Method of preparing a self-reinforced silicon nitride ceramic of high
fracture toughness
    3.
    发明授权
    Method of preparing a self-reinforced silicon nitride ceramic of high fracture toughness 失效
    制备高断裂韧性的自增强氮化硅陶瓷的方法

    公开(公告)号:US5021372A

    公开(公告)日:1991-06-04

    申请号:US398801

    申请日:1989-08-25

    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。

    Self-reinforced silicon nitride ceramic of high fracture toughness
    4.
    发明授权
    Self-reinforced silicon nitride ceramic of high fracture toughness 失效
    自增强氮化硅陶瓷具有高断裂韧性

    公开(公告)号:US4919689A

    公开(公告)日:1990-04-24

    申请号:US290720

    申请日:1989-02-28

    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%。

    Self-reinforced silicon nitride ceramic of high fracture toughness and a
method of preparing the same
    5.
    发明授权
    Self-reinforced silicon nitride ceramic of high fracture toughness and a method of preparing the same 失效
    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:US4883776A

    公开(公告)日:1989-11-28

    申请号:US148748

    申请日:1988-01-27

    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%。

    SiAlON composites and method of preparing the same
    10.
    发明授权
    SiAlON composites and method of preparing the same 失效
    SiAlON复合材料及其制备方法

    公开(公告)号:US5413972A

    公开(公告)日:1995-05-09

    申请号:US178377

    申请日:1993-12-23

    CPC分类号: C04B35/597

    摘要: A dense, substantially glass free, SiAlON ceramic material and method of making such material. The material has at least an alpha-SiAlON phase and a beta-SiAlON phase and exhibits excellent high temperature oxidation resistance and strength, good room temperature toughness and hardness, and a density greater than at least 95 percent of theoretical. The method of making the ceramic material is simple and includes adding AlN in an amount sufficient to allow formation of a desired amount of alpha-SiAlON, and in addition, convert SiO.sub.2 and Al.sub.2 O.sub.3 into the beta-SiAlON phase, preferably, by adding AlN in an amount between about 1.3X+0.08Y-0.0045XY and about 1.3X+0.2Y-0.0024XY, wherein X is a weight percent of the SiO.sub.2 based on total weight of the Si.sub.3 N.sub.4 in the mixture and Y is a weight percent of alpha-SiAlON phase desired.

    摘要翻译: 密实的,基本上无玻璃的SiAlON陶瓷材料和制造这种材料的方法。 该材料至少具有α-SiAlON相和β-SiAlON相,并且具有优异的高温抗氧化性和强度,良好的室温韧性和硬度,并且密度大于理论值的至少95%。 制造陶瓷材料的方法是简单的,并且包括以足以形成所需量的α-SiAlON的量加入AlN,此外,将SiO 2和Al 2 O 3转化成β-SiAlON相,优选通过将AlN加入到 在约1.3X + 0.08Y-0.0045XY和约1.3X + 0.2Y-0.0024XY之间的量,其中X是基于混合物中Si 3 N 4的总重量的SiO 2的重量百分比,Y是α -SiAlON相需要。