Low temperature, pressureless sintering of silicon nitride
    7.
    发明授权
    Low temperature, pressureless sintering of silicon nitride 失效
    低温无压烧结氮化硅

    公开(公告)号:US5376602A

    公开(公告)日:1994-12-27

    申请号:US178376

    申请日:1993-12-23

    申请人: Kevin J. Nilsen

    发明人: Kevin J. Nilsen

    IPC分类号: C04B35/584 C04B35/58

    CPC分类号: C04B35/584

    摘要: A silicon nitride-based powder composition that yields sintered bodies having a density of at least 3.15 g/cm.sup.3 by pressureless sintering. The composition includes silicon nitride and an amount of bismuth oxide as a phase transition aid in addition to magnesium oxide, aluminum oxide, zirconium oxide and, optionally, silicon dioxide. The sintered bodies can be produced at temperatures of 1650.degree. C. or less.

    摘要翻译: 一种氮化硅基粉末组合物,其通过无压烧结得到密度为至少3.15g / cm 3的烧结体。 除了氧化镁,氧化铝,氧化锆和任选的二氧化硅之外,组合物包括氮化硅和一定量的作为相转移助剂的氧化铋。 烧结体可以在1650℃或更低的温度下生产。

    Method to produce a transition metal carbide from a partially reduced transition metal compound
    8.
    发明授权
    Method to produce a transition metal carbide from a partially reduced transition metal compound 失效
    从部分还原的过渡金属化合物制备过渡金属碳化物的方法

    公开(公告)号:US06495115B1

    公开(公告)日:2002-12-17

    申请号:US08703153

    申请日:1996-08-29

    IPC分类号: C01B3130

    摘要: A transition metal carbide is formed from a precursor mixture comprising at least one of the group consisting of: a transition metal, a transition metal carbide and a transition metal oxide. The precursor mixture may contain the desired transition metal carbide (e.g., WC), but if the desired transition metal carbide is present in the precursor mixture, there is necessarily a significant amount of another compound such as a transition metal oxide, undesired carbide (e.g., W2C) or transition metal. The method involves forming an admixture by mixing the precursor mixture with a sufficient amount of carbon to carburize the precursor mixture to the transition metal carbide and reacting the admixture in an inert or reducing atmosphere at a temperature for a time sufficient to convert the admixture to the transition metal carbide, wherein the admixture is reacted in the presence of a means to enhance transfer of heat into the admixture, an inert or reducing gas flowing through at least a portion of the admixture or combination thereof.

    摘要翻译: 过渡金属碳化物由包含过渡金属,过渡金属碳化物和过渡金属氧化物中的至少一种的前体混合物形成。 前体混合物可以含有所需的过渡金属碳化物(例如WC),但是如果所需的过渡金属碳化物存在于前体混合物中,则必须有大量的其它化合物,例如过渡金属氧化物,不期望的碳化物(例如 ,W2C)或过渡金属。 该方法包括通过将前体混合物与足够量的碳混合来形成混合物,以将前体混合物渗碳到过渡金属碳化物,并将该混合物在惰性或还原性气氛中在足以将混合物转化为 过渡金属碳化物,其中所述混合物在增加热量进入所述混合物的手段的存在下反应,惰性或还原气体流过所述混合物的至少一部分或其组合。