摘要:
In Al.sub.2 O.sub.3 composites used for machining tools for difficult-cutting steels, etc., strength and toughness are increased by dispersing a Ti compound with an average grain size of not greater than 0.1 .mu.m into Al.sub.2 O.sub.3 particles with the average grain size of not greater than 1 .mu.m, and SiC whiskers are uniformly dispersed between each of Al.sub.2 O.sub.3 particles to form a nanocomposite structure.For the above-mentioned purpose, SiC whiskers containing 0.3 to 1.5% by weight of oxygen, dissolved uniformly in a solvent, are mixed with a starting Al.sub.2 O.sub.3 series powder containing Ti compounds to form a uniform mixture, which is then molded and sintered.
摘要:
A mixed powder containing: 5-30 wt % of SiC whiskers; 3-30 wt % of a sintering auxiliary agent composed of one kind or more of oxides of Mg, Si, Ca, Ti, Zr, Cr, Ni, Y and rare earth elements; and an Al.sub.2 O.sub.3 powder as a base material; or further containing 0.5-40 wt % of one kind or more of compounds composed of one kind or more of transient elements in the groups IVa, Va, and VIa of the periodic table and one kind or more of C, N and B, are compacted and subjected to pressureless-sintering in a nitrogen containing inert gas atmosphere at a temperature between 1500.degree. and 1900.degree. C. With this method, the SiC whiskers containing Al.sub.2 O.sub.3 based ceramic material, which is densified and has a sufficient strength and toughness, can be formed in a complex shape and a large size.
摘要翻译:含有5-30重量%的SiC晶须的混合粉末; 3-30重量%由Mg,Si,Ca,Ti,Zr,Cr,Ni,Y和稀土元素的一种或多种氧化物构成的烧结助剂; 和作为基材的Al 2 O 3粉末; 或进一步含有0.5-40重量%的一种或多种由元素周期表IVa,Va和VIa族中的一种或多种瞬态元素组成的化合物和C,N和B中的一种或多种。 压制并在含氮惰性气体气氛中在1500〜1900℃的温度下进行无压烧结。通过这种方法,含有Al2O3基陶瓷材料的SiC晶须被致密化并具有足够的强度和韧性,可以 形成复杂的形状和大尺寸。
摘要:
The present invention relates to a nitrogen containing high speed steel obtained by the powder metallurgical process, which comprises at least 0.40% N, 1.6 to 15% V, C in an amount satisfying the relationship of 0.5 + 0.2V (%) .ltoreq. (C + N) .ltoreq. 0.8 + 0.2V (%), at least one element selected from the group consisting of up to 15% of Cr, up to 10% of Mo, up to 20% of W and up to 15% of Co with the balance iron.
摘要:
The specification describes a method for producing high density sintered silicon nitride(Si.sub.3 N.sub.4) having a relative density of at least 98%. In a first step, silicon nitride powder is compacted into a desired shape. It is then presintered in a second step, generally, under normal pressure to obtain a presintered body having a relative density of at least 92%. In a third step, the presintered body is subjected to a hot isostatic pressing(HIP) in an inert gas atmosphere of 1500-2100.degree. C. and of nitrogen gas partial pressure of at least 500 atm. Since the presintering does not require any capsule, it is possible to produce high density sintered Si.sub.3 N.sub.4 of complex configurations. As a sintering aid, Y.sub.2 O.sub.3 --Al.sub.2 O.sub.3 --MgO system sintering aid is particularly effective. To improve the strength of sintered Si.sub.3 N.sub.4, it is effective to add a heat treatment step after the HIP and maintain the temperature of the sintered Si.sub.3 N.sub.4, above 500.degree. C. for a while. Between the second and third steps, the temperature of the presintered body is preferably maintained above 500.degree. C. These temperature controls are effective not only to improve the strength of sintered Si.sub.3 N.sub.4 but also to save the thermal energy and to shorten the production cycle.
摘要翻译:该说明书描述了一种生产相对密度至少为98%的高密度烧结氮化硅(Si3N4)的方法。 在第一步骤中,氮化硅粉末被压制成所需的形状。 通常在常压下第二步骤中预烧结,得到相对密度至少为92%的预烧结体。 在第三步骤中,在1500-2100℃的惰性气体气氛和至少500atm的氮气分压下对预烧结体进行热等静压(HIP)。 由于预烧结不需要任何胶囊,因此可以生产复合结构的高密度烧结Si 3 N 4。 作为烧结助剂,Y2O3-Al2O3-MgO体系的烧结助剂特别有效。 为了提高烧结Si3N4的强度,在HIP之后添加热处理步骤并将烧结的Si 3 N 4的温度保持在500℃以上一段时间是有效的。 在第二和第三步骤之间,预烧结体的温度优选保持在500℃以上。这些温度控制不仅有效地提高了烧结Si 3 N 4的强度,而且有效地节约了热能并缩短了生产周期。
摘要:
The specification describes a method for producing high density sintered silicon nitride (Si.sub.3 N.sub.4) having a relative density of at least 98%. In a first step, silicon nitride powder is compacted into a desired shape. It is then pre-sintered in a second step, generally, under normal pressure to obtain a presintered body having a relative density of at least 92%. In a third step, the presintered body is subjected to a hot isostatic pressing (HIP) in an inert gas atmosphere of 1500.degree.-2100.degree. C. and of nitrogen gas partial pressure of at least 500 atm. Since the presintering does not require any capsule, it is possible to produce high density sintered Si.sub.3 N.sub.4 of complex configurations. As a sintering aid, Y.sub.2 O.sub.3 --Al.sub.2 O.sub.3 --MgO system sintering aid is particularly effective. To improve the strength of sintered Si.sub.3 N.sub.4, it is effective to add a heat treatment step after the HIP and maintain the temperature of the sintered Si.sub.3 N.sub.4 above 500.degree. C. for a while. Between the second and third steps, the temperature of the presintered body is preferably maintained above 500.degree. C. These temperature controls are effective not only to improve the strength of sintered Si.sub.3 N.sub.4 but also to save the thermal energy and to shorten the production cycle.
摘要翻译:该说明书描述了一种生产相对密度至少为98%的高密度烧结氮化硅(Si3N4)的方法。 在第一步骤中,氮化硅粉末被压制成所需的形状。 通常在常压下在第二步骤中预烧结,得到相对密度至少为92%的预烧结体。 在第三步骤中,将预烧结体在1500-2100℃的惰性气体气氛和至少500atm的氮气分压下进行热等静压(HIP)。 由于预烧结不需要任何胶囊,因此可以生产复合结构的高密度烧结Si 3 N 4。 作为烧结助剂,Y2O3-Al2O3-MgO体系的烧结助剂特别有效。 为了提高烧结Si3N4的强度,在HIP之后添加热处理步骤并将烧结的Si 3 N 4的温度保持在500℃以上一段时间是有效的。 在第二和第三步骤之间,预烧结体的温度优选保持在500℃以上。这些温度控制不仅有效地提高了烧结Si 3 N 4的强度,而且有效地节约了热能并缩短了生产周期。
摘要:
The specification describes a method for producing high density sintered silicon nitride(Si.sub.3 N.sub.4) having a relative density of at least 98%. In a first step, silicon nitride powder is compacted into a desired shape. It is then presintered in a second step, generally, under normal pressure to obtain a presintered body having a relative density of at least 92%. In a third step, the presintered body is subjected to a hot isostatic pressing(HIP) in an inert gas atmosphere of 1500-2100.degree. C. and of nitrogen gas partial pressure of at least 500 atm. Since the presintering does not require any capsule, it is possible to produce high density sintered Si.sub.3 N.sub.4 of complex configurations. As a sintering aid, Y.sub.2 O.sub.3 -Al.sub.2 O.sub.3 -MgO system sintering aid is particularly effective. To improve the strength of sintered Si.sub.3 N.sub.4, it is effective to add a heat treatment step after the HIP and maintain the temperature of the sintered Si.sub.3 N.sub.4 above 500.degree. C. for a while. Between the second and third steps, the temperature of the presintered body is preferably maintained above 500.degree. C. These temperature controls are effective not only to improve the strength of sintered Si.sub.3 N.sub.4 but also to save the thermal energy and to shorten the production cycle.
摘要翻译:该说明书描述了一种生产相对密度至少为98%的高密度烧结氮化硅(Si3N4)的方法。 在第一步骤中,氮化硅粉末被压制成所需的形状。 通常在常压下第二步骤中预烧结,得到相对密度至少为92%的预烧结体。 在第三步骤中,在1500-2100℃的惰性气体气氛和至少500atm的氮气分压下对预烧结体进行热等静压(HIP)。 由于预烧结不需要任何胶囊,因此可以生产复合结构的高密度烧结Si 3 N 4。 作为烧结助剂,Y2O3-Al2O3-MgO体系的烧结助剂特别有效。 为了提高烧结Si3N4的强度,在HIP之后添加热处理步骤并将烧结的Si 3 N 4的温度保持在500℃以上一段时间是有效的。 在第二和第三步骤之间,预烧结体的温度优选保持在500℃以上。这些温度控制不仅有效地提高了烧结Si 3 N 4的强度,而且有效地节约了热能并缩短了生产周期。
摘要:
A method for producing a high strength sintered silicon carbide, the method comprising: molding a mixture of silicon carbide powder and a sintering aid into a green compact of a predetermined shape: preliminarily sintering the green compact to obtain a preliminarily sintered compact having a relative density higher than 80%; charging the preliminarily sintered compact in a HIP equipment without using a capsule; and subject the preliminarily sintered compact to a HIP treatment in a high-temperature and high-pressure N.sub.2 gas atmosphere maintaining a pressure higher than 500 atms and a temperature in the range of 1400.degree.-2300.degree. C.
摘要:
A nitrogen containing powder metallurgical tool steel comprising at least 0.40% N, 1.6 - 15% V, C in an amount satisfying the relationship of0.2 + 0.2 V(%).ltoreq.(C + N)