Manganese deoxidation equilibrium in liquid Fe-36 pct ni alloy at 1773 K

Abstract

The Fe-36 pct Ni alloy, exhibiting anomalously low thermal expansion over a wide temperature range, is used as a functional and electromagnetic material. [1] Since it is especially used as TV Shadow mask, the demand has rapidly increased. Manganese in the alloy is one of the important elements for the complex deoxidation. However, no data are available for the thermodynamic prediction of the manganese deoxidation equilibrium in this alloy.In most investigations [2][3][4][5][6] on thermodynamic aspects of deoxidation equilibrium in Fe-Ni alloys, the effect of nickel on activity coefficients of oxygen and deoxidizing elements in liquid iron have been evaluated by using their experimental results in Fe-Ni melts and the values recommended by Fig. 1-Solubility of iron in magnesium-lithium melts at 700 ЊC as deter-JSPS, [7] which is primarily concerned with dilute solutions mined in this work.based on liquid iron as the solvent. Application of those data, good basically for dilute solutions to the case of high alloy steels such as Fe-36 mass pct Ni (Invar), is not considered to conform to the concept of Wagner's interaction parameters. [8] In order to overcome the irrelevance mentioned previously, the present study aims to obtain thermodynamic data by taking the solution of "liquid Fe-36 mass pct Ni" as the solvent melt, which basically eliminates separate consideration of the effect of nickel on other elements. This article deals with determination of thermodynamic data (equilibrium constant and interaction parameter) of manganese deoxidation equilibrium in the range of manganese content covering from 0.1 to 5 mass pct in Fe-36 pct Ni alloy at 1773 K.The electromagnetic levitation-melting technique using a cold crucible was employed to study manganese deoxidation equilibrium in liquid Fe-36 pct Ni. The cold crucible is a copper crucible manufactured by Crystalox Ltd. (Oxford, UK) (32 ϫ 10 Ϫ3 m i.d., 52 ϫ 10 Ϫ3 m o.d., and 135 ϫ 10 Ϫ3 m length) and constructed in multiple segments, each of which is water cooled (flow rate: 20 L/min). A high-frequency current (20 kW and 170 kHz) is applied to the coil surFig. 2-Solubility of iron in liquid magnesium (liquidus of solid iron) as rounding the crucible.determined in this work and as known from the literature. [3,4,5] This noncontact levitation melting enabled avoidance of any contamination or side effect resulting from a container material such as MnO crucible. Furthermore, deoxidation products are completely exposed on the surface of the molten metal and accumulated at the bottom of the metal in the REFERENCES form of a thin film by gravity. Therefore, metal and oxides are completely separated from each other [9,10] to the detection 1. K. Schwerdtfeger, C.-T. Mutale, and A. Ditze: Metall. Mater. Trans. limit, and hence, all oxygen and manganese existing in the B, 2002, vol. 33B, pp. 355-64.metal can be regarded as solute, not in the form of oxide.

Characterization of rigid polypropylene‐based microcellular foams produced by batch foaming processes

“…Several works have compared the mechanical properties of thermoplastic nanocomposite foams with that of the respective unfilled ones under tensile and compressive conditions [7, 8]. In all cases, the incorporation of layered silicates resulted in higher moduli and tensile strengths, in some cases the nanocomposite foams displaying higher specific moduli than the solid unfilled material [9].…”