Production aspects of inhomogeneous hot deformation in as-cast CuNi25 alloy

The attempts are being made to achieve the best economic effects and material properties by optimizing the hot working process. Production requires an accurate, specified conditions and knowledge about the influence of almost all parameters on the manufacturing process. The misapplication of materials or technological parameters lead to increase in costs and often to destruction of materials during their production or operating. The fundamental problems associated with the hot working processes of many metals and commercial alloys focus on two associated phenomena: intermediate temperature loss of ductility and hot brittleness. This paper is the result of examination of these two phenomena on industrial CuNi25 alloys, with different chemical compositions and structures. Deformation rate has also been taken into consideration. All tests have been conducted in air, within 0.3-0.7 T_H, selected ones in argon atmosphere. Numerous techniques are used to characterize material properties and to identify the inhomogeneities occurring, for example high temperature tensile tests, infrared thermography, SEM, EDS, WDS and TEM.