Rapid solidification processing generally results in fine grained and macrosegregation free microstructures and improves hot-workability of highly-alloyed metals (e.g., superalloys and high alloy steels).
The Osprey Process is a technology capable of producing rapidly solidified materials in thick sections. The Process also provides a means of producing dense preforms in one step directly from liquid metal by an integrated atomisation/deposition operation. Consequently, the Process retains most of advantages of powder metallurgy methods while eliminating the major disadvantages resulting from multi-stage processing (i.e., powder production, sizing, compaction and sintering) which often leads to high cost and oxide contamination in the final product.
In the present investigation, the Osprey Process has been applied satisfactorily to mill rolls.
The results indicate that:
(1) A fine grain size is obtained by controlling operational parameters;
(2) The as-sprayed preform exhibits higher mechanical properties compared with conventional cast rolls;
(3) In experimental tests the amount of wear of Osprey products is 1/2 to 1/6 of conventional cast material; and
(4) The life of Osprey rolls under service in a wire-rod mill exceeded that of conventional ones by two to three times.