Deposition of plating metals to improve crack growth life

In this work, cracks in AISI 4130 low-alloy steel specimens were artificially filled with closure materials through plating on the crack faces. Premature crack closure occurred and in doing so, retarded the subsequent crack extension. The closure materials included plating metals such as electroless and electroplated nickel, and electroless copper. This work investigated how the mechanical properties and in-crack distribution of these plating metals affect crack retardation. The extent to which specimen thickness, crack prop-opening load and sucker site affect crack retardation was also studied. Experimental results indicate that the strength of the plating metal and the deposit thickness T 2 affect the post-plate crack propagation the most, while deposit volume is the next most influential factor. In the case of satisfactory crack face plating, crack growth rate decreased substantially and even caused crack arrest. Finally, the elastic-wedge model can accurately predict crack development after the infiltration of electroless nickel plating.