T. Babul, A. Nakonieczny, Institute of Precision Mechanics, Warsaw, Poland; J. Senkara, Warsaw University of Technology, Warsaw, Poland
The paper deals with chosen issures related to application of silver alloy in grazing pipes in the aircraft engines.Investigated AgCu42Ni2 alloy feature is a significant difference between solidus (771
oC) and liquidus (893
oC) temperatures which is rather unusual for fillers. Hence, it is tendency to split into two phases in the course of the joining process.
Brazing experiments were conducted in 10-6Tr vaccum environment. Impact of different means of anisotropic and isotropic surface preparation ( including sand blasting, polishing, wear cloth application and nickel plating) on the filler spreading was tested. Surface area covered by the liquid alloy as the function of brazing temperatute and time is also presented. Structures of obtained joins were investigated by optical microscopy, scanning electron microskopy, x-ray diffractometry and micro-hardness measurments. A particular attention was attracted onto interfaces and difussion layers. The paper presents also the analysis of phenomena that occour during the liquid front through the gap beetween two cylindrical surfaces.
In the paper were presented results of 18-8 stainless steel brazing by AgCu42Ni2. Brazing experiments were conducted in 10-6 Tr vacuum environment. Impact of different means of isotropic and anisotropic surface preparation (including sand blasting, polishing, wear cloth application, and nickel plating) on the filler spreading was tested. Surface area covered by the liquid alloy as a function of brazing temperature and time is also presented. Results presented investigation which were carry out on the samples and on the hydraulic, air- and fuel-operated pipes use in the aircraft engines.
