Papers by Author: Julius C. Schuster

Abstract: The ternary system Cu-Si-Ti was investigated using XRD, SEM-EDX, and DTA. The existence of two ternary phases τ1-CuSiTi and τ2-TiSi2-xCux as well as their crystal structures are confirmed. The isothermal section at 800°C is corroborated. From DTA data of equilibrated alloys a reaction scheme linking the isotherm at 700°C with the liquidus surface is derived. Using data on primary crystallisation of as cast alloys a projection of the liquidus surface is proposed.

Abstract: SiC reacts with metals at high temperatures, and forms metal carbide, metal silicide and metal carbosilicide depending on metal. The interface structure is formed by the diffusion path between SiC and metal. The diffusion path between SiC and metal is described on the tie-lines of the corresponding M-Si-C (M:Metal) ternary phase diagram. The interfacial strength of SiC/Metal depends on the thickness of reaction zones at SiC/Metal couple. Although the increase of thickness of reaction zone improves the interfacial strength of SiC/Metal couple, the increase of internal stress and crack in the reaction zone degrades the strength of the couple. The interfacial strength of SiC/Metal couple yields the maximum at a thickness of reaction zone.

Abstract: The phases occurring upon lead free soldering of copper substrates using indium, which contains for improved wetting additions of Ti, belong to the ternary system Cu-In-Ti. Thus, the liquidus surface of the ternary system Cu-In-Ti is determined using DTA data. Alloys were prepared from high purity metals by arc melting under pure argon. Before measuring the heating curves, all alloys were equilibrated at appropriate temperatures and XRD phase analysis were performed. A reaction scheme linking the phase equilibria found in the annealed alloys to the liquid phase is obtained. A projection of the resulting liquidus surface, which is dominated by the primary crystallisation field of the congruently melting Heusler phase t1-Cu2TiAl, is presented. In the In-rich composition corner the liquid phase solidifies in a ternary eutectic (In) + Ti2In5 + Cu11In9 at 155°C.