摘要:
The invention relates to a process for the production of a ceramic/fiber composite.The process comprises impregnating fibers with a molten polysilazane in a first step, converting the polysilazane in the fibers into the infusible state in a second step and, in a third step, heating the impregnated fibers to 800.degree. to 2000.degree. C. in an atmosphere of nitrogen, noble gas, or ammonia.
摘要:
The invention relates to a high-strength ceramic composite, in particular made from silicon nitride, a process for its preparation and its use. The process comprises impregnating an open-pore matrix with a molten polysilazane in a first step and, in a second step, heating the impregnated matrix to 800.degree. to 2500.degree. C. under a blanketing gas, such as nitrogen or a noble gas, or to 800.degree. to 1500.degree. C. under a gas containing ammonia. The high-strength ceramic composite prepared can be used as a component to be subjected to high thermal, mechanical or corrosive stress.
摘要:
The invention relates to a novel sinterable ceramic powder, to its preparation, to its processing to form silicon nitride ceramic and to said material itself and its use. The sinterable ceramic powder is prepared by dissolving the polysilazane of formula (I)[CH.sub.3 SiHNH].sub.n [CH.sub.3 SiN].sub.nwhere n is about 10 to 12, in an organic solvent, suspending a pulverulent sinter aid in this solution and then evaporating the solvent and pyrolyzing the residue in an inert gas atmosphere at 500.degree. to 1600.degree. C.The resulting ceramic powder can be used to form a shaped article and then to manufacture silicon nitride ceramic by sintering. It is also possible, however, to form a shaped article from the as yet unpyrolyzed residue obtained after evaporation of the solvent, and then to pyrolyze and sinter said article.The ceramic obtained can be used to manufacture components subject to high mechanical, thermal and corrosive stress.
摘要翻译:本发明涉及一种新型的可烧结陶瓷粉末,用于其制备,以形成氮化硅陶瓷的加工以及所述材料本身及其用途。 可烧结陶瓷粉末是通过在有机溶剂中溶解式(I)[CH3SiHNH] n [CH3SiN] n的聚硅氮烷[N,N-二甲基甲酰胺] n [CH3SiN] n,其中n为约10〜12,将粉状烧结助剂悬浮在该溶液中,然后蒸发溶剂, 在惰性气体气氛中在500〜1600℃下热解残渣。得到的陶瓷粉末可用于形成成形制品,然后通过烧结制造氮化硅陶瓷。 然而,也可以从蒸发溶剂后获得的仍然未裂解的残余物形成成型制品,然后热解并烧结所述制品。 获得的陶瓷可用于制造受到高机械,热和腐蚀应力的部件。
摘要:
The invention relates to novel polysilazanes, the preparation thereof, the further processing thereof to form silicon nitride-containing ceramic material, and this material itself. In order to prepare the polysilazanes, dialkylaminoorganyldichlorosilanes of the formula RSiCL.sub.2 --NR'R' are reacted with ammonia. The polysilazanes can then be pyrolyzed to form silicon nitride-containing ceramic material. The polysilazanes according to the invention dissolve in customary aprotic solvents.
摘要:
The invention relates to novel polysilazanes, the preparation thereof, the further processing thereof to form silicon nitride-containing ceramic material, and this material itself. In order to prepare the polysilazanes, dialkylaminoorganyldichlorosilanes of the formula RsiCl.sub.2 -Nr'R' are reacted with ammonia. The polysilazanes can then be pyrolyzed to form silicon nitride-containing ceramic material. The polysilazanes according to the invention dissolve in customary aprotic solvents.
摘要:
The invention relates to novel polymeric hydridochlorosilazanes, to their preparation, to their processing to form ceramic materials containing silicon nitride, and to said materials themselves. The polymeric hydridochlorosilazanes are prepared by reacting oligohydridoorganosilazanes of the general formula (R.sup.1 SiHNH).sub.n, in which n is about 3 to about 12, with at least one of the chlorosilanes R.sup.2 SiHCl.sub.2, R.sup.3 SiCl.sub.3, Cl.sub.2 R.sup.4 Si--CH.sub.2 CH.sub.2 --SiR.sup.4 Cl.sub.2 or Cl.sub.3 Si--CH.sub.2 CH.sub.2 --SiR.sup.5 Cl.sub.2 at 30.degree. C. to 300.degree. C., where the radicals independently of one another have the following meanings:R.sup.1 =a C.sub.1 -C.sub.6 alkyl or C.sub.2 -C.sub.6 alkenyl group,R.sup.2 =a C.sub.2 -C.sub.6 alkenyl group if R.sup.2 SiHCl.sub.2 is reacted with the oligosilazanes by itself, orR.sup.2 =a C.sub.1 -C.sub.6 alkyl or C.sub.2 -C.sub.6 alkenyl group if R.sup.2 SiHCl.sub.2 is reacted with the oligosilazanes as a mixture with other chlorosilanes, andR.sup.3, R.sup.4, R.sup.5 =a C.sub.1 -C.sub.6 alkyl or C.sub.C.sub.2 -C.sub.6 alkenyl group,and where R.sup.3 SiCl.sub.3 is used only as a mixture with at least one of the other chlorosilanes (containing R.sup.2, R.sup.4 or R.sup.5).The polymeric hydridochlorosilazanes according to the invention can be converted into polysilazanes by reaction with ammonia, and these in turn can be pyrolyzed to form ceramic materials containing silicon nitride.
摘要:
The invention relates to a novel sinterable ceramic powder, to its preparation and to its further processing to give a silicon nitride ceramic, and to this material itself and its use. The sinterable ceramic powder is produced by melting a polysilazane or dissolving it in an organic solvent, suspending a powdered sinter aid in this melt or solution, then pyrolyzing the melt, or the residue obtained after evaporation of the solvent, at 500.degree. to 1600.degree. C. in a protective gas atmosphere, the polysilazane eitherA) being obtainable by reacting at least one of the oligosilazanes of the formula (I) ##STR1## in which a, b, c and d are the mole fractions of the respective structural units and where 0.ltoreq.a.ltoreq.1, 0.ltoreq.b.ltoreq.1, 0.ltoreq.c.ltoreq.0.7, 0.ltoreq.d.ltoreq.0.7, 0.3.ltoreq.a+b, c+d.ltoreq.0.7 and n is approximately 2 to approximately 12, with at least one of the chlorosilanes R.sup.6 R.sup.7 SiCl.sub.2, R.sup.8 SiCl.sub.3, Cl.sub.2 R.sup.9 Si--CH.sub.2 CH.sub.2 --SiR.sup.9 Cl.sub.2 and Cl.sub.3 Si--CH.sub.2 CH.sub.2 SiR.sup.10 Cl.sub.2 at 30.degree. to 300.degree. C., where, independently of one another, R.sup.1, R.sup.2, R.sup.4, R.sup.6, R.sup.7 and R.sup.8 are H, C.sub.1 -C.sub.6 -alkyl or C.sub.2 -C.sub.6 -alkenyl and R.sup.3, R.sup.5, R.sup.9 and R.sup.10 are C.sub.1 -C.sub.6 -alkyl or C.sub.2 -C.sub.6 -alkenyl, orB) having the following formula ##STR2## in which R and R* can be identical or different and R and R* are C.sub.1 -C.sub.4 -alkyl, vinyl or phenyl and R' is C.sub.1 -C.sub.4 -alkyl and x and y are the mole fractions of the two structural units, where x+y=1 and x=0.7-0.95.A molded article can be formed from the ceramic powder thus obtained and a silicon nitride ceramic then produced by sintering. However, a molded article can also be formed from the solidified melt or the still unpyrolyzed residue obtained after evaporating the solvent and this article can then by pyrolyzed and sintered.Components subject to severe mechanical, thermal and corrosive stress can be produced from the ceramic obtained.
摘要:
Polymeric hydridothiosilazanes, processes for the preparation thereof, silicon nitride-containing ceramic materials which can be prepared therefrom, and the preparation thereof.The invention relates to novel polymeric hydridothiosilazanes, the preparation thereof, the conversion thereof into silicon nitride-containing ceramic material, and this material itself. To prepare the polymeric hydridothiosilazanes, oligohydridoalkylsilazanes (RSiHNH).sub.n are reacted with elemental sulfur and ether as solvents. The polymeric hydridothiosilazanes can then be pyrolyzed to form silicon nitride-containing ceramic material.
摘要:
The invention relates to novel polysilazanes, their preparation, their further processing to ceramic material containing silicon nitride and this material itself. To prepare the polysilazanes, Si,Si'-diorganyl-N-alkyl-tetrachloro-disilazanes of the formula RSiCl.sub.2 -NR'-SiCl.sub.2 R are reacted with ammonia. The polysilazanes can then be pyrolyzed to ceramic material containing silicon nitride. The polysilazanes according to the invention dissolve in the customary aprotic solvents.
摘要:
The invention relates to fiber composite materials and a process for their preparation.The process comprises impregnating fibers with a molten polysilazane in a first step, converting the polysilazane in the fibers into the non-fusible state in a second step, and heating the impregnated fibers to 800.degree. to 2000.degree. C. in a nitrogen, noble gas or ammonia atmosphere in a third step.