1a and 2 contained herein are identical to that described in prior art international application wo 99 67435 by inventors winfried esser et al after being cast alloys 1 1a and 2 were heat treated at 1250 degrees c 2282 degrees f for 4 hours full solution heat treatment of the secondary u03b3 u2032 phase as was described in wo 99 67435 the present inventors including said winfried esser have now recognized the benefit of using only a partial heat treatment regiment resulting in the data for alloy 3 first presented herein the alloy for heat 3 was heat treated at a temperature and for a duration in such way that the solution of a secondary phase in the matrix is only partly performed the nickel based superalloy has as a secondary phase the u03b3 u2032 phase the inventive heat treatment is performed at 1213 u00b0 c for at least 1 h which is not the solution temperature of a secondary phase e g y u2032 phase for this alloy also the temperature of 1250 u00b0 c called the full solution temperature which is normally used for a full solution treatment can be used but only for a shorter time than in the prior art so that the secondary phase is not completely solved in the matrix the not solubilized amount of the secondary phase in the matrix is smaller than 90 70 50 or 30 vol according to the geometry and producibility after the heat treatment because grain boundary cracks are avoided in order to increase the yield rate of specimens and desired mechanical properties of the specimen the alloy can have a single crystal structure or only having grains along one direction optionally an ageing heat treatment can be performed for this composition at 1080 u00b0 c.