Computer aided visual inspection of the technical condition of gas turbin blades during their operation period

Due to speciflc working conditions of gas turbine blades and difficult access to them their technical condition during their operation period is generally evaluated by a visual method with the aid of advanced optical devices. This paper presents the analysis of forms and kinds of gas turbine blade damages, which affect their reliability. The paper presents features of non-destructive inspection methods used for diagnosing the technical conditions of the said blades during their operation period. Special atiention was given to methods of computer aided diagnosing of the technical condition ofgas turbine blades, which increase the reliability of evaluation of the said condition and therefore reduce costs and enhance the operational safety. The process of destruction of a gas turbine blade starts with the destruction of a protective coating, in consequence of which the initial material of a blade is subject to a direct aggressive impact of the waste gas. This causes the material to directly overheat, which manifests itself in detrimental changes in its microstructure. There is need for a more common use of non-destructive methods for a current evaluation of the state of overheated aircraft engine turbine blades.