Horizontal centrifugal casting is an effective method for the production of hollow metal with good mechanical properties, low defect, cast
to size and relatively cheap. The ability of a metal to satisfy the above requirements highly depends on its microstructure. In this study, the
relationship between microstructural parameters such as grain size and the amount of phases with bulk hardness of SnCu4Pb3 is concerned
in three areas of the product. Consequently, to achieve the desired hardness of the product in a particular area, the interaction of two
factors of the microstructure including, grain size and particles amount of the hard intermetallic compositions (Cu6Sn5) should be noted.
Particles of the Fe-Al type (less than 50 µm in diameter) were sprayed onto the 045 steel substrate by means of the detonation method. The TEM, SAED and EDX analyses revealed that the Fe-Al particles have been partially melted in the experiment of coating formation. Particle undergone melting even within about 80% of its volume. Therefore, solidification of the melted part of particles was expected. Solidification differed significantly due to a large range of chemical composition of applied particles (from 15 at.% Al up to 63 at.% Al). A single particle containing 63 at.% Al was subjected to the detailed analysis, only. The TEM / SAED techniques revealed in the solidified part of particle three sub-layers: an amorphous phase, A ε , periodically situated FeAl + Fe2Al5 phases, and a non-equilibrium phase, Nε . A hypothesis dealing with the inter-metallic phases formation in such a single particle of the nominal composition 0 N = 0.63 is presented. At first, the solid / liquid system is treated as an interconnection: substrate liquid nonmelted particle part / / . Therefore, it is suggested that the solidification occurs simultaneously in two directions: towards a substrate and towards a non-melted part of particle. The solidification mechanism is referred to the Fe-Al meta-stable phase diagram. It is shown that the melted part of particle solidifies rapidly according to the phase diagram of meta-stable equilibrium and at a significant deviation from the thermodynamic equilibrium.
Ti-containing steel weld metals with Al contents of 0.01-0.085% were prepared. The effects of Al contents on the inclusions evolution were investigated by means of thermodynamic calculations coupled with electron probe micro-analyses and transmission electron microscopy. The results show that the inclusions in the 0.01% Al weld metal are mainly composed of ilmenite with some amounts of (Mn-Si-Al)-oxide and titanial_spinel. When Al content is increased up to 0.035%, a more amount of corundum and a small amount of pseudobrookite are formed. In 0.085% Al weld metal, the (Mn-Si-Al)-oxide disappears completely, and the inclusions contain a substantial amount of corundum, in addition to a minimal amount of pseudobrookite. Ti3O5, MnTi2O4 and MnTiO3 are the primary constituents of pseudobrookite, titanial_spinel and ilmenite, respectively. Titanial_spinel and ilmenite have higher amounts of Mn, but lower Ti levels compared with pseudobrookite. In the case of presence of a considerable amounts of titanial_spinel and ilmenite, Mn-depleted zone is formed in matrix around the inclusions.
Thermodynamic descriptions of the ternary Fe-B-Cu system and its binary sub-system B-Cu aredeveloped in the context of a new Fe-B-X (X = Cr, Cu, Mn, Mo, Ni, Si, Ti, V, C) database. The thermodynamic parameters of the other binary sub-systems (Fe-B and Fe-Cu) are taken from earlier assessments. Experimental thermodynamic and phase equilibrium data available in the literature have been used for the optimization of the Fe-B-Cu and B-Cu systems’ thermodynamic parameters. The solution phases are described using a substitutional solution model and the compounds (two borides of the Fe-B system) are treated as stoichiometric phases. A good agreement was obtained between the calculated and the experimental thermodynamic and phase equilibrium data.
Thermodynamic descriptions of the ternary Fe-B-Si system and its binary sub-system, B-Si, are developed in the context of a new Fe-B-X (X = Cr, Ni, Mn, V, Si, Ti, C) database. The thermodynamic parameters of the other binary sub-systems, Fe-Si and Fe-B, are taken from earlier assessments. Experimental thermodynamic and phase equilibrium data available in the literature has been used for the optimization of the thermodynamic parameters of the Fe-B-Si and B-Si systems. The solution phases are described using substitutional solution model and the compounds (silicides and borides) are treated as stoichiometric phases. The calculated and experimental thermodynamic and phase equilibrium data were found to be in good agreement.
Thermodynamic optimizations of the ternary Fe-B-Ti system and its binary sub-system, B-Ti are presented. The thermodynamic descriptions of the other binaries, Fe-Ti and Fe-B, are taken from the earlier studies slightly modifying the Fe-Ti system assessment. The adjustable parameters of the Fe-B-Ti and B-Ti systems are optimized in this study using the experimental thermodynamic and the phase equilibrium data from the literature. The solution phases of the system are described using the substitutional solution model and the compounds (including borides) are treated as stoichiometric phases. The results show a good correlation between the calculated and measured thermodynamic and phase equilibrium data.
Thermodynamic description of the Fe-B-C system in its iron-rich corner is developed in the context of a new Fe-B-X (X = Cr, Ni, Mn, Si, Ti, V, C) database. The thermodynamic parameters of the binary sub-systems, Fe-B, Fe-C and B-C, are taken from earlier assessments modifying the B-C description. The parameters of the Fe-B-C system are optimized in this study using experimental thermodynamic and phase equilibrium data from the literature. Liquid, beta-rhombo-B and graphite phases are described using the substitutional solution model, while the ferrite (bcc), the austenite (fcc), the cementite (M3C) and the M23C6 phases are described with the sublattice model and the borides, Fe2B, FeB and B4C, are treated as stoichiometric phases. A good correlation was obtained between the calculated and the experimental thermodynamic and phase equilibrium data. The description is recommended to be used at the composition region of wt% C + wt% B < 15 and at temperatures below 2700oC.
Thermodynamic optimizations of the ternary Fe-B-Mo system and its binary sub-system B-Mo are presented. The Fe-B-Mo description is then extended to the quaternary Fe-B-Cr-Mo system by assessing the ternary B-Cr-Mo system. The thermodynamic descriptions of the other binaries (Fe-B, Fe-Cr, Fe-Mo, B-Cr, and Cr-Mo) and the other ternaries (Fe-B-Cr and Fe-Cr-Mo) are taken from earlier studies. In this study, the adjustable parameters of the B-Mo, Fe-B-Mo, and B-Cr-Mo systems were optimized using the experimental thermodynamic and the phase equilibrium data from the literature. The solution phases of the system (liquid, bcc and fcc) are described with the substitutional solution model, and most borides are treated as stoichiometric phases or semistoichiometric phases, using a simple two-sublattice model for the latter. The system’s intermetallic phases, Chi, Mu, R, and Sigma (not dissolving boron) as well as boride M3B2, based on a formulation of (Cr,Fe)(Cr,Fe,Mo)2(B)2, are described with a three-sublattice model. Reasonable agreement is obtained between the calculated and measured phase equilibria in all four systems: B-Mo; Fe-B-Mo; B-Cr-Mo; and Fe-B-Cr-Mo.