Deposition of plating metals to improve crack growth life

In this work, cracks in AISI 4130 low-alloy steel specimens were artificial ly filled with closure materials through plating on the crack faces. Premat ure crack closure occurred and in doing so, retarded the subsequent crack e xtension. The closure materials included plating metals such as electroless and electroplated nickel, and electroless copper. This work investigated h ow the mechanical properties and in-crack distribution of these plating met als affect crack retardation. The extent to which specimen thickness, crack prop-opening load and sucker site affect crack retardation was also studie d. 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 accurate ly predict crack development after the infiltration of electroless nickel p lating. (C) 2001 Elsevier Science Ltd. All rights reserved.