摘要:
A SiAlON armor ceramic made from a starting powder mixture including silicon nitride powder. The armor ceramic includes a ceramic body that has between about 64 weight percent and about 90 weight percent alpha SiAlON phase that contains an alpha SiAlON-bound rare earth element. The ceramic body also has between about 5 weight percent and about 35 weight percent of a beta SiAlON phase of the formula Si6−zAlzOzN8−z wherein the value of “z” ranges between about 0.10 and about 0.35. The alpha SiAlON-bound rare earth element in the alpha SiAlON phase is present as a result of the starting powder mixture that contains between about 1 weight percent and about 7 weight percent of an oxide of the alpha SiAlON-bound rare earth element. The ceramic body has a fracture toughness (KIC) greater than about 6.00 MPa·m1/2 and a Vickers hardness (HVN) equal to greater than about 19.3 GPa.
摘要翻译:由起始粉末混合物制成的SiAlON铠装陶瓷,包括氮化硅粉末。 铠装陶瓷包括陶瓷体,其具有约64重量%至约90重量%的含有与SiAlON结合的稀土元素的αAlON相。 陶瓷体还具有约5重量%至约35重量%的式Si 6-z Al z O z N 8-z的βSiAlON相,其中“z”的值在约0.10和约0.35之间。 由于起始粉末混合物含有约1重量%至约7重量%的α-SiAlON结合的稀土元素的氧化物,所以存在αSiAlON相中的αSiAlON结合的稀土元素。 陶瓷体的断裂韧性(KIC)大于约6.00MPa·m1 / 2,维氏硬度(HVN)等于大于约19.3GPa。
摘要:
Additions of substitutional transition metal elements are made to improve the densifiability of titanium diboride while eliminating or minimizing the presence of deleterious grain boundary phases in the resultant bulk titanium diboride articles.
摘要:
A SiAlON material that includes a two phase composite of an alpha prime SiAlON phase and a beta prime SiAlON phase. The alpha prime phase contains ytterbium. The alpha prime SiAlON phase being present in an amount between about 25 weight percent and about 85 weight percent of the two phase composite. The SiAlON material further includes an intergranular phase.
摘要:
A continuous process for the manufacture of a ceramic sintered compact wherein the process comprises the steps of: forming a green compact from a powder mixture comprising a first component comprising compounds which contain elements of silicon, aluminum, oxygen and nitrogen; and the powder mixture further comprising a second component comprising a compound of at least one element selected from the group consisting of yttrium, scandium, cerium, lanthanum and the metals of the lanthanide series, and the second component comprising between 0.1 and 10 weight percent of the powder mixture; heat treating the green compact wherein the heat treatment comprises continuously passing the green compact through at least one heating zone so as to produce a sintered compact.
摘要:
A dual phase silicon aluminum oxynitride material comprising a first phase Si-Al-O-N, commonly referred to as .beta.-Si-Al-O-N, and a second phase Si-Al-O-N referred to as .alpha.-Si-Al-O-N. In addition to the double phase Si-Al-O-Ns, there is included a glassy type material which can formulate up to ten percent by weight of the total composition. The material may be manufactured by forming a polytype material made from reacted alumina, aluminum nitride and silicon nitride. The polytype material may be mixed with further powders of silicon nitride and an oxide of yttrium, lithium or calcium and finally reacted to a double phase Si-Al-O-N material where hardness is increased as the additional .alpha.-Si-Al-O-N is increased without significantly affecting its strength.The material may be formed in situ by mixing aluminum nitride, alumina, silicon nitride, together with an oxide of yttrium, lithium or calcium. These materials can then be sintered to a final product containing a double phase Si-Al-O-N. Control of the alumina content in the polytype or in situ methods affects the percentage of .alpha.-Si-Al-O-N produced in the final product. The hardness of the material increases with the .alpha.-Si-Al-O-N content without significantly affecting its transverse rupture strength.
摘要:
Industrial blast nozzles are disclosed which have liners made, at least in part, from a SiAlON-containing ceramic material which has a surface resistance of about 12 megaOhms or less and an erosion rate of about 1.9×10−4 cm3/g or less. The SiAlON-containing ceramic material preferably contains a two-phase SiAlON, silicon carbide, and a conductive phase that is one or more of titanium nitride, tantalum nitride, zirconium nitride, and titanium carbide.
摘要翻译:公开了具有至少部分由含有SiAlON的陶瓷材料制成的衬垫的工业喷射喷嘴,其具有约12兆欧姆或更小的表面电阻和约1.9×10 -4 cm 3 / g以下的侵蚀速率。 含SiAlON的陶瓷材料优选包含两相SiAlON,碳化硅和作为氮化钛,氮化钽,氮化锆和碳化钛中的一种或多种的导电相。
摘要:
End mills are disclosed which may be made monolithically of ceramic or other materials. The cutting portions of the end mills have lengths of cut that are no more than twice their cutting diameters and cores which are at least 0.7 times their cutting diameters. Their axial blades have cutting edges with negative radial rake and are separated by helical flutes. Their cutting ends have negative axial rake and are gashed ahead of center and have radial cutting edges with negative rake. Such end mills also have radiused corners and gashes transitioning from radial to axial at a flute. Methods of milling materials using such ceramic end mills are also disclosed.
摘要:
Industrial blast nozzles are disclosed which have liners made, at least in part, from a SiAlON-containing ceramic material which has a surface resistance of about 12 megaOhms or less and an erosion rate of about 1.9×10−4 cm3/g or less. The SiAlON-containing ceramic material preferably contains a two-phase SiAlON, silicon carbide, and a conductive phase that is one or more of titanium nitride, tantalum nitride, zirconium nitride, and titanium carbide.
摘要翻译:公开了具有至少部分由含有SiAlON的陶瓷材料制成的衬垫的工业喷射喷嘴,其具有约12兆欧姆或更小的表面电阻和约1.9×10 -4 cm 3 / g以下的侵蚀速率。 含SiAlON的陶瓷材料优选包含两相SiAlON,碳化硅和作为氮化钛,氮化钽,氮化锆和碳化钛中的一种或多种的导电相。
摘要:
A method for making a crystallized ceramic body containing a two phase composite comprising an alpha prime SiAlON phase that contains ytterbium and a beta prime SiAlON phase, the process includes the steps of: blending together a starting powder mixture that upon densification forms the SiAlON ceramic, the starting powder includes at least about 70 weight percent silicon nitride powder wherein the silicon nitride powder contains beta silicon nitride in an amount less than or equal to about 1.6 weight percent of the silicon nitride powder, and the starting powder further including one or more powders that contribute aluminum, oxygen, and nitrogen to the beta prime SiAlON phase and aluminum, oxygen, nitrogen and ytterbium to the alpha prime SiAlON phase; and densifying the starting powder mixture to form a densified SiAlON ceramic; and heat treating the densified ceramic body so as to form the crystallized ceramic body wherein the alpha prime SiAlON phase comprises at least about 20 weight percent of the two phase composite.
摘要:
A SiAlON material that includes a two phase composite of an alpha prime SiAlON phase and a beta prime SiAlON phase. The alpha prime phase contains ytterbium. The alpha prime SiAlON phase being present in an amount between about 25 weight percent and about 85 weight percent of the two phase composite. The SiAlON material further includes an intergranular phase.