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BALLISTIC COMPRESSION TEST FOR DETERMINING HIGH STRAIN RATE CONSTITUTIVE EQUATION FOR SOLID MATERIALS
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Forming of Metal Matrix Composites
No full textMetal matrix composites (MMCs), through a proper selection of matrix and reinforcement, offer unusual combinations of physical and mechanical properties such as high specific strength and stiffness, high thermal and electrical conductivity, high wear resistance, good corrosion resistance, and good impact and fatigue properties, together with superior thermal stability when compared to the unreinforced matrix alloys. Near net shape forming and improvements in microstructure, strength, and ductility can be achieved in discontinuously reinforced MMCs through the application of primary or secondary plastic deformation processes such as extrusion, rolling, forging, superplastic forming, or friction processing. Thermomechanical processing can be directly a part of the production process or follow a primary stage of fabrication or consolidation. Processing can be mainly divided in hot and cold working, the latter often followed by annealing. The set of processing conditions (e.g., temperature, total deformation, deformation rate) is of crucial importance with respect to the resultant microstructural and consequently mechanical properties, and must be optimized with respect to the system to be processed (matrix alloy, reinforcing hard phase, reinforcement size, and volume content).Several research groups have dedicated considerable efforts to study hot and cold forming of MMCs and their effects on microstructural and mechanical properties. In this review, the latest research findings in mechanical forming processes for MMCs are illustrated. The main emphasis is dedicated to particulate-reinforced, Al-based MMCs, due to their widespread use, although references to other significant systems, and in particular to other light metal matrices, are also given. For each treated forming process, the current advances in processing optimization and enhancement in mechanical properties and microstructure are described and discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The effect of post-weld heat-treatment on mechanical-properties and residual-stresses mapping in welded structural steel
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