Procedure for Choosing Abrasive Composites for Grinding Materials that are Hard to Machine

A procedure is developed for choosing a composite abrasive for grinding alloys that are hard to machine based on considering the interaction of tool materials and the article being machined. The efficiency of the procedure is demonstrated using the composite created for machining titanium alloys.__________Translated from Poroshkovaya Metallurgiya, Nos. 1–2(441), pp. 31–38, January–February, 2005.     

Melting Diagram for the Cr ― Nb ― C System in the (Cr) ― (Nb) ― ― (NbC) Region

Powder Metallurgy and Metal Ceramics - It is shown from experimental tests on alloys in the Cr ― Nb ― C system in the region of the (Cr) ― (Nb) ― (NbC) subsystem at the...     

An Experimental and Computational Modeling Study on Additively Manufactured Micro-Architectured Ti–24Nb–4Zr–8Sn Hollow-Strut Lattice Structures

Herein, the design, manufacturing, and mechanical testing of hollow-strut lattice structures of the metastable β-titanium alloy Ti–24Nb–4Zr–8Sn (Ti2448) are performed. Due to the absence of studies in the literature, this study focusses on two important aspects: 1) the designing of micro-architectured lattice structures and 2) metastable β-titanium alloy. Face-centered cubic (FCC) and body-centered cubic (BCC) hollow-strut lattices are designed by computer-aided design and manufactured by laser powder bed fusion. The microstructure of the hollow lattices shows plates of α″-martensite phase within the β phase. The FCC hollow lattice structure shows higher tensile strength compared to the BCC hollow lattice structure, while the load-bearing capability of the FCC hollow lattice structure is lower than that of the BCC hollow lattice structure. At lower strains, the tensile force-displacement curve of the hollow lattice structure matches the simulated tensile force-displacement curve. At higher strains, a large deviation in the force-displacement curve is observed in the hollow lattices.     

Effect of pulsed magnetic treatment on the corrosion of titanium

ABSTRACT

Results of corrosion tests of titanium in the initial state and after treatment using pulsed magnetic field are presented. It is shown that samples after treatment have better corrosion resistance due to the formation of denser and finer corrosion products with better adhesion to the substrate. Samples after treatment have more homogeneous microstructure due to a substantial increase of dislocations which are uniformly distributed. Mechanisms of dislocation multiplication and a model explaining the effect of the treatment on the corrosion are discussed.

This paper is part of a themed issue on Materials in External Fields.     

lectrical Conductivity of Permeable Sintered Materials Composed of Discrete Randomly Oriented Fibers

A theory of the electrical properties of individual contacts is used to calculate the electrical conductivity of porous materials composed of discrete fibers with imperfect interparticle contacts. It is shown that the conductivity of these materials may be substantial even if the contacts are small. The materials' conductivity is significantly affected by a change in the relative length of the fibers.