HOT COMPRESSION DEFORMATION BEHAVIOR AND CONSTITUTIVE ANALYSIS OF EXTRUDED MAGNESIUM-BISMUTH ALLOYS

The isothermal compression experiments of Mg-2Bi alloys were carried out under different temperature and strain rate by Gleeble 3500D thermal simulation test machine. The rheological stress variation law of the Mg-2Bi alloy was analysed under 200-350oC and 0.001-1.0 s-1. The results present that the peak stress enhances and the dynamic recrystallization grain size reduces with the decline of deformation temperature and the improvement of strain rate during isothermal compression of the Mg-2Bi alloy. In addition, the activation energy for alloy deformation is 130.03 kJ/mol. The softening mechanism of the Mg-2Bi alloy is mainly twin and dynamic recrystallization under a low temperature (200oC) condition. While at a higher temperature of 350oC, the softening mechanism changes to single dynamic recrystallization.

Hot Deformation Behavior and Constitutive Analysis of As-Extruded Mg–6Zn–5Ca–3Ce Alloy Fabricated by Rapid Solidification

The plasticity of Mg–6Zn–5Ca–3Ce alloy fabricated by rapid solidification (RS) at room temperature is poor due to its hexagonal-close-packed (HCP) structure. Therefore, hot deformation of RS Mg–6Zn–5Ca–3Ce alloy at elevated temperature would be a major benefit for manufacturing products with complex shapes. In the present study, hot deformation behavior of as-extruded Mg–6Zn–5Ca–3Ce alloy fabricated by RS was investigated by an isothermal compression test at a temperature (T) of 573–673 K and strain rate (ε˙) of 0.0001–0.01 s−1. Results indicated that the flow stress increases along with the declining temperature and the rising strain rate. The flow stress behavior was then depicted by the hyperbolic sine constitutive equation where the value of activation energy (Q) was calculated to be 186.3 kJ/mol. This issue is mainly attributed to the existence of fine grain and numerous second phases, such as Mg2Ca and Mg–Zn–Ce phase (T’ phase), acting as barriers to restrict dislocation motion effectively. Furthermore, strain compensation was introduced to incorporate the effect of plastic strain on material constants (α,Q,n,lnA) and the predicted flow stresses under various conditions were roughly consistent with the experimental results. Moreover, the processing maps based on the Murty criterion were constructed and visualized to find out the optimal deformation conditions during hot working. The preferential hot deformation windows were identified as follows: T = 590–640 K, ε˙ = 0.0001–0.0003 s−1 and T = 650–670 K, ε˙ = 0.0003–0.004 s−1 for the studied material.

HUSSERL. CUERPO PROPIO Y ALIENACIÓN

En este artículo intento aclarar qué significa la distinción yo / cuerpo (propio), en el contexto de los análisis de la constitución de Ideas II. Me interesa el énfasis husserliano en la dimensión constituida del cuerpo propio, del cuerpo como «haber» del yo en que desembocan las descripciones del cuerpo vivido. Esta posesión señala una condición antropológica fundamental y entraña la posibilidad de su enajenación o no reconocimiento. En un primer momento describo la esfera vivida del cuerpo propio, su condición animal en los términos husserlianos de la segunda parte de Ideas II; en el segundo apartado expongo la problemática de la constitución de la propiedad del cuerpo en relación con los niveles constitutivos del yo (pasivo o activo); finalmente, en un tercer apartado desarrollo los aspectos principales de la alienación o enajenación del yo y el cuerpo a través de experiencias cenestésicas e hiperestésicas en las que la sensibilidad primaria parece opacar la fuerza del yo libre y activo. En cada momento o nivel se muestra el hiatum yo / cuerpo, la condición de una conciencia irreductible al cuerpo y de un cuerpo inapresable en los límites del yo, como conciencia en vigilia.In this paper I wish to clarify the I/(own) living body distinction, an issue that arises from constitutive analysis in Ideas II. I am interested in Husserlian insistence on the constituted dimension of the own living body, the body as the “have” of I, where all descriptions of living body arrive. This possession points to the fundamental anthropological condition and encloses the possibility of being alienated or not recognized. The first step is to describe the lived sphere of the own body, its animal condition, as exposed in the second part of Ideas II. The second part is aimed at disclosing the constitution of bodily “owness” in relation to different constitutive levels. Finally, in the third part I delve into most important features of alienation of the I and the body through kinaesthetic and hiperaestetic experiences, in which primary sensitivity seems to numb the force of free and active I. The hiatum between I and body reveals itself as awake consciousness on every level of constitution, and it is the condition for a consciousness irreducible to the body and a body which is not apprehended in the limits of I.

Dasein and World: Heidegger’s Reconceiving of the Transcendental After Husserl

The following examines Heidegger’s analysis of world and Dasein from a transcendental perspective. It is argued that Heidegger’s reflections on the interconnected themes of world and Dasein reveal the tensions that exist between the transcendental claims before and after Being and Time and the analysis of worldliness. It begins by looking at Heidegger’s early analysis of Husserl’s critique of psychologism and naturalism, assessing what this tells us about Heidegger’s analysis of world and nature. It subsequently addresses Heidegger’s transformation of Husserlian phenomenology, and intentionality in particular, arguing against interpreters who claim Heidegger’s interconnected concepts of Dasein and world are reducible to one another and hence phenomenologically problematic. In order to respond to this reading, the article examines the twin themes of, on the one hand, transcendental constitutive analysis in Heidegger’s work, Dasein as disclosive and ‘world entering’, and, on the other hand, the centrality of the world and the realm of nature as always more than Dasein’s constitutive relationship to it. In order to understand what Heidegger means by worldliness, the article will look at Heidegger’s reflections on nature as the world’s other, which nonetheless needs to be understood on the basis of worldliness.