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Angular Pressing (angular + pressing)

Distribution by Scientific Domains
Polymers and Materials Science88%

Kinds of Angular Pressing

  • channel angular pressing
    		•
  • equal channel angular pressing
    		•

    Selected Abstracts

    Equal Channel Angular Pressing of a Mg,3Al,1Zn Alloy with Back Pressure,

    ADVANCED ENGINEERING MATERIALS, Issue 8 2010
    Feng Kang
    Abstract An extruded Mg,3Al,1Zn alloy bar is subjected to 1,4 passes equal channel angular pressing (ECAP) with or without 125,MPa backpressure via route Bc at 200,°C. Both strength and ductility are significantly increased after ECAP with backpressure; this is in strong contrast to the case of ECAP without backpressure, where significant improvement in ductility is accompanied by obvious decrease in yield strength from texture softening. Compared to ECAP without backpressure, much enhanced grain refinement, and the split of the dominant texture component of (0002) pole were observed with scatter intensity peaks in the case after ECAP with backpressure. This turns out to be resulted mainly from the activation of new slip system together with enhanced dynamic recrystallization under the effect of backpressure. The improvement of both strength and ductility in Mg,3Al,1Zn alloy through ECAP with back pressure provides a better approach to meet the engineering requests on comprehensive performance of this light alloy. [source]

    Cost-Affordable Technique Involving Equal Channel Angular Pressing for the Manufacturing of Ultrafine Grained Sheets of an Al,Li,Mg,Sc Alloy,

    ADVANCED ENGINEERING MATERIALS, Issue 8 2010
    Rustam Kaibyshev
    A two-step process consisting of modified equal channel angular pressing (ECAP) and subsequent isothermal rolling (IR) was developed to produce thin sheets of aluminum alloys with ultra-fine grained (UFG) structure. Significant increase in the efficiency of ECAP was attained by using flat billets and a back pressure system. The incorporation of final IR into technologic route provides a reduced strain which is necessary to impose for the fabrication of thin sheets with UFG structure. In addition, it allows producing relatively "long billets." In order to demonstrate the feasibility of this technique an Al,5.1Mg,2.1Li,0.17Sc,0.08Zr (wt %) alloy was subjected to ECAP at 325,°C to a total strain of ,8 using processing route CX. The operation time of this processing did not exceed 15,min. Subsequent IR at the same temperature with a total reduction of 88% was applied to produce thin sheets with a 1.8,mm thickness and an average size of recrystallized grains of ,1.6,µm. These sheets exhibit extraordinary high superplastic ductilities. In addition, this material demonstrated almost isotropic mechanical behavior at room temperature. The maximum elongation-to-failure of ,2700% was attained at a temperature of 450,°C and an initial strain rate of 1.4,×,10,2 s,1. Thus it was demonstrated that the two-step processing consisting of ECAP with a back pressure followed by IR was a simple technique providing potential capability for the fabrication of superplastic sheets from an Al,Mg,Li,Sc alloy on a commercial scale. [source]

    Consolidation of Particles by Severe Plastic Deformation: Mechanism and Applications in Processing Bulk Ultrafine and Nanostructured Alloys and Composites,

    ADVANCED ENGINEERING MATERIALS, Issue 8 2010
    Kenong Xia
    Severe plastic deformation (SPD) can be used to consolidate particles into bulk ultrafine and nanostructured materials. SPD consolidation relies on plastic deformation of individual particles, rather than diffusion, to achieve bonding and thus can be carried out at much lower temperatures. Using examples of consolidation of Al particles by back pressure equal channel angular pressing (BP-ECAP), it is demonstrated that full consolidation is achieved when the particles are sheared to disrupt the surface oxide layer whereas consolidation is impossible or incomplete in the case of particles sliding over each other. The effects of particle characteristics such as size, shape, strength and surface condition, as well as processing parameters including temperature and back pressure, are discussed to shed light on the mechanism of SPD consolidation. Potential applications of SPD in powder consolidation and processing of bulk ultrafine and nanostructured materials are discussed. [source]

    Equal Channel Angular Pressing of a Mg,3Al,1Zn Alloy with Back Pressure,

    ADVANCED ENGINEERING MATERIALS, Issue 8 2010
    Feng Kang
    Abstract An extruded Mg,3Al,1Zn alloy bar is subjected to 1,4 passes equal channel angular pressing (ECAP) with or without 125,MPa backpressure via route Bc at 200,°C. Both strength and ductility are significantly increased after ECAP with backpressure; this is in strong contrast to the case of ECAP without backpressure, where significant improvement in ductility is accompanied by obvious decrease in yield strength from texture softening. Compared to ECAP without backpressure, much enhanced grain refinement, and the split of the dominant texture component of (0002) pole were observed with scatter intensity peaks in the case after ECAP with backpressure. This turns out to be resulted mainly from the activation of new slip system together with enhanced dynamic recrystallization under the effect of backpressure. The improvement of both strength and ductility in Mg,3Al,1Zn alloy through ECAP with back pressure provides a better approach to meet the engineering requests on comprehensive performance of this light alloy. [source]

    Cost-Affordable Technique Involving Equal Channel Angular Pressing for the Manufacturing of Ultrafine Grained Sheets of an Al,Li,Mg,Sc Alloy,

    ADVANCED ENGINEERING MATERIALS, Issue 8 2010
    Rustam Kaibyshev
    A two-step process consisting of modified equal channel angular pressing (ECAP) and subsequent isothermal rolling (IR) was developed to produce thin sheets of aluminum alloys with ultra-fine grained (UFG) structure. Significant increase in the efficiency of ECAP was attained by using flat billets and a back pressure system. The incorporation of final IR into technologic route provides a reduced strain which is necessary to impose for the fabrication of thin sheets with UFG structure. In addition, it allows producing relatively "long billets." In order to demonstrate the feasibility of this technique an Al,5.1Mg,2.1Li,0.17Sc,0.08Zr (wt %) alloy was subjected to ECAP at 325,°C to a total strain of ,8 using processing route CX. The operation time of this processing did not exceed 15,min. Subsequent IR at the same temperature with a total reduction of 88% was applied to produce thin sheets with a 1.8,mm thickness and an average size of recrystallized grains of ,1.6,µm. These sheets exhibit extraordinary high superplastic ductilities. In addition, this material demonstrated almost isotropic mechanical behavior at room temperature. The maximum elongation-to-failure of ,2700% was attained at a temperature of 450,°C and an initial strain rate of 1.4,×,10,2 s,1. Thus it was demonstrated that the two-step processing consisting of ECAP with a back pressure followed by IR was a simple technique providing potential capability for the fabrication of superplastic sheets from an Al,Mg,Li,Sc alloy on a commercial scale. [source]

    Suppression of Ni4Ti3 Precipitation by Grain Size Refinement in Ni-Rich NiTi Shape Memory Alloys,

    ADVANCED ENGINEERING MATERIALS, Issue 8 2010
    Egor A. Prokofiev
    Severe plastic deformation (SPD) processes, such as equal channel angular pressing (ECAP) and high pressure torsion (HPT), are successfully employed to produce ultra fine grain (UFG) and nanocrystalline (NC) microstructures in a Ti,50.7,at% Ni shape memory alloy. The effect of grain size on subsequent Ni-rich particle precipitation during annealing is investigated by transmission electron microscopy (TEM), selected area electron diffraction (SAD, SAED), and X-ray diffraction (XRD). It is observed that Ni4Ti3 precipitation is suppressed in grains of cross-sectional equivalent diameter below approximately 150,nm, and that particle coarsening is inhibited by very fine grain sizes. The results suggest that fine grain sizes impede precipitation processes by disrupting the formation of self-accommodating particle arrays and that the arrays locally compensate for coherency strains during nucleation and growth. [source]

    Enhanced Strength and Ductility of Ultrafine-Grained Ti Processed by Severe Plastic Deformation,

    ADVANCED ENGINEERING MATERIALS, Issue 8 2010
    Irina Semenova
    This work deals with the study of strength and ductility in ultrafine-grained (UFG) Ti Grade 4 produced by equal channel angular pressing (ECAP) in combination with subsequent thermomechanical treatments. We found that additional annealing of UFG Ti resulted in unusual enhancement of strength and ductility, which is associated with not only small grain size but also with a grain boundary structure. The origin of this phenomenon is investigated using the results of transmission electron microscopy and atom probe tomography. The innovation potential of UFG Ti for medical use is considered. [source]

    Experimental Evidence for Grain-Boundary Sliding in Ultrafine-Grained Aluminum Processed by Severe Plastic Deformation,

    ADVANCED MATERIALS, Issue 1 2006
    Q. Chinh
    Evidence for grain boundary sliding in ultrafine-grained aluminum after processing with equal channel angular pressing (ECAP) is presented (see Figure). Pure aluminum is used as a model material; depth sensing indentation testing and atomic force microscopy are used to measure the nature of the displacements around indentations for samples in an annealed and work-hardened condition, and after processing using ECAP. [source]

    Temperature effects on the fatigue behavior of ultrafine-grained copper produced by equal channel angular pressing

    PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 15 2004
    X. W. Li
    Abstract The fatigue behavior of ultrafine-grained copper produced by equal channel angular (ECA) pressing was investigated at temperatures between room temperature and 573 K under a constant stress amplitude of 200 MPa. Cyclic softening was found to be much more evident and the corresponding fatigue life decreases rapidly as temperature increases. This phenomenon was considered as being the result of the grain coarsening and microstructural changes in the coarsened grains associated with the testing temperature. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]