GB1278254A - Improvements in or relating to forming spherical bodies by pressing powder - Google Patents

Abstract

1278254 Moulding spherical powder bodies UNITED KINGDOM ATOMIC ENERGY AUTHORITY 19 Sept 1969 [26 June 1968] 30497/68 Heading B5A In the compression moulding of spherical bodies from powders, e.g. of sinterable UO 2 spherical bodies, between two opposed relatively movable members each whereof has a hemispherical body defining concavity, uneven compaction is avoided by providing at least one of the members with a chamfer externally of the concavity and directed away from an opposed surface of the other member surrounding the concavity whereby, as the members move together, the powder flows outwardly of the cavity into a bounded region and is progressively compacted between the chamfer and the opposed surface. In the Fig. 2 embodiment, a sphere 18 is compacted between a stationary lower die 11 and an upper punch 9, provided with the chamfer 14, which is displaced theretowards through the powder 21 located in a bounded region 16 defined within a member 15. After removal of the punch 9, the sphere 18 is separated from the surrounding progressively compacted powder 17 by upward displacement of a die ejector 13, whereafter the member 15 is displaced laterally of the die 11 for ejection therefrom of the sphere 18 and compacted powder 17, by a downwardly movable ejector. The flash surrounding the sphere is removed by tumbling. In other embodiments, the chamfer may alternatively be provided on the stationary die, or on both the punch and on the die which is also provided with an ejector (not shown) for the progressively compacted material.