Cast Intermetallic Alloys and Composites Based on Them by Combined Centrifugal Casting—SHS Process
This work aims to establish a scientific and engineering background in the production of cast multicomponent alloys and metalmartix composite (MMCs) via Self-Propagating High Temperature Synthesis (SHS, combustion synthesis) which is a novel process technique regarding fast and low-cost production ability. We carried out the search for reactive systems and process parameters that would ensure preparation of cast multicomponent materials in a single process. The principles and methods of the SHS thermite-type reaction processes have been investigated under high-gravity values applying loads up to 1000 g with special centrifuge set-up. In this way we expected to improve the yield of target product, remove gaseous byproducts, diminish the grain size in the product, and make product composition more uniform. The obtained results can be expected to make a theoretical background for industrial-scale manufacturing of heat-resistant intermetallic alloys, master alloys, catalysts, MMCs etc.
NiAl-based electrodes by combined use of centrifugal SHS and induction remelting
NiAl-based electrodes of a required size were fabricated by combined use of centrifugal SHS casting and induction remelting in an inert atmosphere and characterized by modern analytical methods. Thus produced electrode materials exhibiting high chemical purity and low content of impurity gases (0.005 wt % O, 0.0001 wt % N) can be recommended for use in centrifugal plasma sputtering of micro granules via the plasma rotating electrode process (PREP).
Mechnical properties of NiAl–Cr alloys in relation to microstructure and atomic defects
Abstract The quasi-binary eutectic NiAl–Cr of the ternary Ni–Al–Cr system is composed of B2 type NiAl(Cr) solid solutions and the b.c.c. transition metal chromium as second phase. This constitution enables a systematic alloy design in dependence on the Cr content for improving elastic stiffness, high temperature strength, creep resistance, and fracture toughness of intermetallic NiAl. Elasticity and mechanical properties of NiAl(Cr) reinforced by nano-sized Cr particles or quasi-continuous Cr fibres of several microns in diameter are presented and discussed in respect to single phase NiAl and literature data. The microstructural characterization and discussion of mechanical properties of NiAl–Cr alloys are supplemented by atom probe field ion microscopy analysis (APFIM). APFIM was used to determine the atomic defect structures, the Cr site preference and reveals Cr segregations at antiphase boundaries.