Monatshefte fiir Chemie 114, 127 135 (1983) Monatshefte Mr Chemie Chemical Monthly © by Springer-Verlag 1983 Investigations Within the Quaternary System Titanium--Nickel--Aluminium--Carbon * Srinivasan Sridharan, Hans Nowotny*, and Steven F. Wayne Institute of Materials Science, The University of Connecticut, Storrs, CT 06268, U.S.A. (Received 26 August 1982. Accepted 14 September 1982) The phase relationship within the quaternary system: titanium--nickel aluminium--carbon was established for 1100°C (quench). A quaternary ~- carbide with a lattice parameter of a = 11.40-11.46s A was found to exist. The H-phase Ti2A1C and the perovskite phase Ti3A1C are no longer stable in the presence of minor amounts of nickel. [Keywords: Quaternary System (Ti, Ni, A1, C); ~-Carbides] Untersuchungen im System Titan--Nickel--Aluminium--Kohlenstoff Die Phasenbeziehungen im Vierstoff-System Ti--Ni--A1--C wurden fiir 1 100 °C (abgeschreckt) ermittelt. Die Existenz eines quaterni~ren Carbids (~- Carbid) mit dem Gitterparame~er a = 11,40--11,463 A wurde nachgewiesen. Die H-Phase Ti2A1C und die Perowskit-Phase TiaA1C sind in Gegenwart von bereits geringen Mengen an Nickel nicht stabil. Introduction Complex carbides of formula Ti2A1C and Ti3A1C have been reported 1 to be of considerable efficiency, when used as abrasives for glass polishing. With nickel proposed as a possible binder, a study of the quaternary system titanium~ickel--aluminium--carbon was of interest. Out of the four ternary systems, namely. Ti--A1--C 2, Ni--A1--C 3, Ti Ni--A14 and Ti--Ni~ 5, 6 which are building up the quaternary, the two first named ternary combinations have extensively * Dedicated to Professor Otto Kratky. 9* 0026-9247/83/0114/0127/$ 01.80