Composite with order within granules and random orientation between granules

摘要

A composite comprises a plurality of granules 38 and 46 arranged together in a randomly oriented manner. Each granule 38 and 46 comprises an ordered arrangement of a first and second phases 40 and 42. The first phase is a cermet, pcd, pcbn or a mixture thereof. Within each granule 38 and 46 the two phases 40 and 42 are both continuous and at least a portion of the first phase contacts the second phase. Each granule 38 and 46 may be cylindrical, with one of the phases 42 disposed around a core 40 formed from the other phase. The first and second phases 40 and 42 may be formed from the same general type of material, and a binder phase 48 may be present between the granules 46. The material may be used to make working surfaces of drill bit cutter cone inserts. Also disclosed are granules made from a rolled stack of sheets made from alternate hard and soft phase materials (fig. 3). These granules then being arranged together in a random manner.