Mechanical Performance of Titanium Alloys with Added Lightweight Interstitial Element for Biomedical Applications

Oxygen is considered to be an impurity in titanium and its alloys, and it enhances their brittleness. However, oxygen has also been recognized as a useful ingredient to improve the mechanical performance of titanium alloys for biomedical applications, because oxygen is a lightweight interstitial element that is non-toxic and non-allergenic. Some reports show that adding oxygen improves both the strength and the ductility of titanium alloys for biomedical applications. The effects of oxygen addition on the mechanical performance of titanium alloys for biomedical aplications are described.

Experimental Study of Phase Composition of B-Fe-Mn-V Alloys and Thermodynamic Calculations of Phase Equilibria in the B-Mn-V and B-Fe-Mn-V Systems

Phase compositions of B-Fe-Mn-V alloys were studied by several experimental methods (DTA measurement, X-ray diffractions, and scanning electron microscopy). Besides the experimental study of the quaternary system, thermodynamic modelling of the ternary B-Mn-V system by the Calphad method and thermodynamic calculations for the quaternary B-Fe-Mn-V system were performed. Calculations for the quaternary system are based on the ternary subsystems (B-Mn-V, B-Fe-V, B-Fe-Mn, and Fe-Mn-V). Boron is modelled as an interstitial element in all solid solutions of vanadium, manganese, and iron. Very good agreement between experimental results and thermodynamic calculations was achieved. The created thermodynamic database is suitable for thermodynamic calculations of phase diagrams for all the ternary subsystems and also for the B-Fe-Mn-V quaternary system.

Sintering Powder Metal Injection Molded (MIM) Titanium Alloys: In Vacuum or Argon?

Titanium alloys processed by the powder metallurgy route (PM) are sintered in vacuum, the higher the better. This philosophy is carried over to MIM titanium alloys. In the MIM process a large amount of out gassing of binders takes place, which affects the vacuum level and hence the interstitial element pick up in the titanium. In this paper the effect of gaseous material in vacuum is discussed and an alternate method of debinding and sintering in argon is proposed. Three processing conditions are applied to MIM tensile bars made from Ti-6-4 materials. First they are debound and sintered under high vacuum, second debound under argon and sintered in high vacuum and third debound and sintered in flowing argon. The physical properties and interstitial element contents are presented and the effects of the material structures due to different processing on the properties are discussed.

Arquitectura renacentista de esquema central: Jerónimo Quijano y su entorno

<p class="Prrafodelista1">Throughout History, many large burial chapels (religious or memorial) with centralized floor plan and independent character have arisen. Jerónimo Quijano, Renaissance Spanish architect, posited certain dual approach; on the one hand, the Renaissance ideal of central scheme and, on the other hand, the direct integration of the duo header-nave without added interstitial element. In this scope, two clear examples of the evolution of Quijano’s architectural proposal in the ancient Cartagena Diocese’s nucleus have been selected:</p><p class="Prrafodelista1">The collegiate church of San Patricio in Lorca, Murcia: an original project (in pursuit of an autonomous central scheme) is a Renaissance monumental temple whose apse has a ‘visual and radial permeability’ towards its ambulatory, the final alteration of its centrality and the modification of the morphology of its apse in order to connect it to the nave transept and therefore articulating the constructive elements of both bodies; thereby ensuring their architectural integration.</p><p class="Prrafodelista1">The Santiago’s parish church in Jumilla, Murcia: entails the full integration (composite floor plan) between a traditional Christian Gothic nave and a renaissance header of three-lobed central plan. Centrality focuses on its header, which in turn contains the transept.</p>As references to Quijano´s architectural approach in his Hispanic environment, it should reflect upon certain reminiscences to Renaissance works in Eastern Andalusia, his direct influence in the Government of Orihuela and subsequently some of his possible influences in the Valencian territory.