Evolution of deformation and recrystallization textures in high-purity Ni and the Ni-5 at. pct W alloy

An attempt has been made to study the evolution of texture in high-purity Ni and Ni-5 at. pct W alloy prepared by the powder metallurgy route followed by heavy cold rolling (∼95 pct deformation) and recrystallization. The deformation textures of the two materials are of typical pure metal or Cu-type texture. Cube-oriented ({001} {100}) regions are present in the deformed state as long thin bands, elongated in the rolling direction (RD). These bands are characterized by a high orientation gradient inside, which is a result of the rotation of the cube-oriented cells around the RD toward the RD-rotated cube ({013} {100}). Low-temperature annealing produces a weak cube texture along with the {013} {100} component, with the latter being much stronger in high-purity Ni than in the Ni-W alloy. At higher temperatures, the cube texture is strengthened considerably in the Ni-W alloy; however, the cube volume fraction in high-purity Ni is significantly lower because of the retention of the {013} {100} component. The difference in the relative strengths of the cube, and the {013} {100} components in the two materials is evident from the beginning of recrystallization in which more {013} {100} -oriented grains than near cube grains form in high-purity Ni. The preferential nucleation of the near cube and the {013} {100} grains in these materials seems to be a result of the high orientation gradients associated with the cube bands that offer a favorable environment for early nucleation

Modelling of full-scale industrial rolling and recrystallisation of strips of alloy 3103

Models for thermo-mechanical processing of metals have recently been developed in a European collaborative project. The scope has been work-hardening, deformation texture evolution and recrystallisation. In the present work these models have been combined with finite element modelling in order to predict microstructural properties of rolled strips of alloy 3103 subjected to full-scale industrial rolling and subsequent recrystallisation annealing. All sub-models demonstrated good prediction power. Integration and combination of the sub-models with finite element modelling represents a powerful tool for virtual processing and optimisation of industrial products and processing conditions

Extrusion of different aluminium alloys ; experimental work and modelling treatments

The present work reports on modelling of extrusion of both generic and commercial alloys. The uniqueness of the work is the coupling of microstructural based models and FEM-models applied and validated both on laboratory and industrial scales. The extrusion trials were carried out at the laboratory press at SINTEF and at an industrial press at SAPA. Focus in that respect was on the extrusion productivity in terms of ram loads (deformation resistance). Correlations between flow stresses obtained in torsion tests and uniaxial compression tests and the extrudability parameters (breakthrough force and die force) for the same materials and same preheating and processing conditions have been studied. The finite element codes ALMA and FIDAP have been coupled with a microstructural based flow stress model (ALFLOW) and tested on the experimental observations. The constitutive parameters for the different alloys, which is an important input in the ALMA model has been obtained by the ALFLOW model (which has been verified by experimental results in torsion and uniaxial compression). In the case of the ALMA model the predictability of extrusion forces of the investigated alloys are very good. The FIDAP predictions of the industrial extrusion trial are also in reasonable agreement with the experiments. In general, it has been shown that the FEM simulations are very sensitive to the applied constitutive equation and the material constants in this equation