公开(公告)号：US4030946A

公开(公告)日：1977-06-21

申请号：US676508

申请日：1976-04-13

申请人： Donald R. Muzyka ,  Robert F. Walley

发明人： Donald R. Muzyka ,  Robert F. Walley

IPC分类号： B22F3/10 ,  C22C1/04 ,  B22F1/04

CPC分类号： B22F3/1003 ,  C22C1/0433 ,  Y10S75/95

摘要： The process prevents prior powder particle boundary delineation by providing one or more surfactant elements which prevent nucleation of carbides at the particle surfaces with the result that carbide precipitation occurs within the powder particles rather than predominantly at the particle surfaces. In one embodiment, a small but effective amount of one or more surfactants is added to prealloyed powder before the powder is enclosed and densified at elevated temperature. In another embodiment, the surfactant is added to the melt of the prealloyed powder prior to atomization. The surfactant should be capable of forming a vapor under the conditions of hot densification, should be a strong oxide and/or sulfide former, must be a weak carbide former, should form oxides and/or sulfides which will not nucleate carbides of other elements, and which, if present in the article made from the powder, will not objectionably affect the desired properties. Useful surfactants include magnesium, barium, calcium, cerium, lanthanum, lithium, neodymium, praseodymium, yttrium, and misch metal.

摘要翻译： 该方法通过提供一种或多种防止颗粒表面碳化物成核的表面活性剂元件来防止现有的粉末颗粒边界划定，结果在粉末颗粒内而不是主要在颗粒表面发生碳化物沉淀。 在一个实施方案中，在将粉末封闭并在升高的温度下致密化之前，向预合金粉末中加入少量但有效量的一种或多种表面活性剂。 在另一个实施方案中，在雾化之前将表面活性剂加入到预合金化粉末的熔体中。 表面活性剂应能在热致密化的条件下形成蒸气，应为强氧化物和/或硫化物，必须为弱碳化物，应形成不会使其它元素的碳化物成核的氧化物和/或硫化物， 如果存在于由粉末制成的制品中，则不会令人反感地影响所需的性能。 有用的表面活性剂包括镁，钡，钙，铈，镧，锂，钕，镨，钇和稀土金属。