Stress raising in laser clad components depending on geometry and defects

The fatigue life of laser clad components is basically determined by stress raisers, which arehere studied by Finite Element Analysis. Cylindrical and square section bars are compared foraxial, bending and torsional load conditions, which induces the macro-stress field withcorresponding stress peaks. Defects from laser cladding such as pores, cracks or the surfaceroughness superimpose additional stress raising action on this stress field. The geometricalposition and orientation of the defects has strong impact on the induced maximum stresslevel. For surface pores it is demonstrated by the fractography that their occurrence within acritical azimuthal range can initiate fatigue cracking. The different conditions of samplegeometry, load situations, materials and defects are compared and discussed. In particular,advanced illustration methods are applied for improved and generalized documentation andexplanation of the trends, both qualitatively and quantitatively. Guidelines are presented, inparticular emphasizing critical defects and situations, such as surface pores that are difficult todetect because of inclusions, or pores just underneath the surface that generate particularlyhigh stress.