saett to framstaella tools by the densification of metallic powders in the foerhoejd temperature in behaallare innehaallande formstyrande bodies coated with keramskikt

摘要

Method for the prepn. of tools by compacting metal powder high temp. in a vessel contg. one or more shape-governing bodies located in defined positions, the metal powder being chosen so that the vol. quotient before and after compaction is less than 2%, and the shape-governing bodies are provided with a max. 5mm coating of hard ceramic particles having a max. size of 5 microns and comprising at least 20 wt.% boron nitride particles, the layer being resistant w.r.t. shape-governing bodies and compacted metal powder. These layers have a low bond strength to the compacted metal powder and permit processing of said compacted powder. Useful for the prepn. of tools having inner moulded cavities, e.g. moulds for casting or spray mouldings.