Refractory Metal Coated Alumina Foams as Support Material for Stem Cell and Fibroblasts Cultivation.

Ceramics are widely used as implant materials; however, they are brittle and may emit particles when used in these applications. To overcome this disadvantage, alumina foams, which represent a 3D cellular structure comparable to that of human trabecular bone structures, were sputter coated with platinum, tantalum or titanium and modified with fibronectin or collagen type I, components of the extracellular matrix (ECM). To proof the cell material interaction, the unmodified and modified materials were cultured with (a) mesenchymal stem cells being a perfect indicator for biocompatibility and releasing important cytokines of the stem cell niche and (b) with fibroblasts characterized as mediators of inflammation and therefore an important cellular component of the foreign body reaction and inflammation after implantation.

Coating Reactions on Vanadium and V-Si-B Alloys during Powder Pack-Cementation.

Alloys in the V-Si-B system are a new and promising class of light-weight refractory metal materials for high temperature applications. Presently, the main attention is focused on three-phase alloy compositions that consist of a vanadium solid solution phase and the two intermetallic phases VSi and VSiB. Similar to other refractory metal alloys, a major drawback is the poor oxidation resistance.

Microstructure and Compression Properties of V‑VB Eutectic Alloys in the V-Si-B System.

The present study reports on the microstructural evolution and room temperature plasticity of V(‑Si)‑B alloys with respect to the V solid solution (V)‑VB phase region. To investigate the occurring effects systematically, different binary V‑B and ternary V‑Si‑B alloys were produced by conventional arc melting. Scanning electron microscope (SEM) analyses and X-ray diffraction (XRD) measurements were used to characterize the resulting as-cast microstructures.