A discrete lattice plane, nearest neighbor, broken bond model with constant bond energies, which had been used to calculate the energy of coherent interphase boundaries in substitutional alloys, was extended to a ternary substitutional-interstitial system to study the chemical interfacial energy between a f.c.c. solid solution and a B1(NaCl) compound. When the regular solution interaction coeffcient of substi-tutional (metal) atoms is positive, interstitial (non-metallic) atoms which have different bond energies with the two metal atoms tend to increase both the composition difference and the interfacial energy. Even when the interaction coeffcient of metal atoms is negative, a miscibility gap and a gradual composition change across the interface occur. The anisotropy of the interfacial energy varies widely according to the magnitude of interaction between the metal and the non-metallic atoms.

The interfacial energy of NaC1 (B 1)-type carbides and nitrides that have a cube-on-cube orientation relationship with austenite was calculated using a discrete lattice-plane (DLP), nearest-neighbor broken-bond (NNBB) method. The required bond energies were evaluated from Miedema's semiempir-ical model for alloys and available thermodynamic data. For Ti, V, Zr, and Nb carbides and nitrides, a significant chemical interfacial energy arises from the large difference in the concentration of nonmetallic atoms between austenite and the compound phase. In contrast to binary fcc/fcc cases, where (111)-type interfaces have the smallest interfacial energy, (100)- and (111)-type interfaces have been found to have the smallest and the largest energy, respectively, of all orientations. The structural component of the interfacial energy arising out of lattice misfit is likely to be larger than the chemical component for these compounds. The orientation dependence of the total interfacial energy and the associated Wulff construction indicate that, due to the retention of the strong anisotropy of the chemical interfacial energy, the equilibrium shape of these B 1 compounds is a cube, possibly with facets at comers and edges over a wide temperature range.

Sympathetic nucleation andled gewise growth are competitive with each other throughout the bainite formation in steels. Many evidences are provided to support this mechanism as follows: ultra-fine structures of bainite and its surface relief, and carbide nucleation inside austenite at the interface of ferrite/austenite, etc.

The interfacial energy of B1 (NaCl)-type carbides and nitrides (designated ξ) having Baker-Nutting orientation relationship with ferrite (χ), i.e. (001)ξ//(001) and [110]ξ//[100], was studied by discrete lattice plane, nearest neighbor broken bond method. The carbide (or nitride) lattice was contracted along the [001] direction so as to make the two lattices isomorphous and coherent at all interface orientations. The chemical interfacial energy of this hypothetical compound is highly anisotropic due to the difference in the M (metal atom)-I (non-metallic atom) coordination number between, for example, (001)-and (100)-type interfaces that would be equivalent in a cubic lattice. As a result, the equilibrium shape is a square plate with (001) broad faces. The anisotropy of the strain energy arising out of a large misfit along the [001] direction may override the anisotropy of chemical energy and dictate the observed square plate morphology of carbides and nitrides in ferrite.

Electroless Cu deposition on a TiN barrier in a CuSO4-HF solution by separated electrodes of a Si wafer and a TiN/Ti/SiO2/Si substrate has been studied. In this electroless Cu plating method, two substrates are fixed on a base made by polystyrene without an external circuit. During plating the Si wafer is oxidized by hydrofluoric acid and releases free electrons; F−ions transmit the free electrons to the TiN/Ti/SiO2/Si substrate, and Cu2+ ions accept the electrons and then directly deposit them on the TiN surface. The morphology, surface coverage, average grain size, crystallography, and adhesion of the as-deposited Cu films on the TiN surface are related to the distance between the two substrates, bath temperature, and concentration of HF and CuSO4. During the plating, Cu is also deposited on the Si wafer and the properties of the Cu films on the Si wafer are discussed in the paper as well. The effect of HF on the TiN barrier in this electroless Cu deposition method is examined by X-ray photoelectron spectroscopy.