Laser Cladding of Iron-Based Self-Fluxing Alloy and its Application in Remanufacturing of Die-Casting Plunger

Abstract

Die-casting plunger often fails due to serious wear on its cylindrical surface. The scrap of plunger used in large die-casting machine results in waste of materials and energy sources, and it is also against environmental protection. Therefore, the laser remanufacturing of die-casting plunger was studied in this paper. Both of the size and the performance of plungers were repaired by laser cladding surface modification using an iron-based self-fluxing alloy. The interface between original failed plunger and laser cladding layer showed a good metallurgical bond. The average thickness of laser cladding layer was 0.845 mm, and the average micro-hardness reached to 750 HV upwards. Microstructure in laser cladding layer was composed by the dendrite primary phase and the ledeburite organization. Iron (Fe), Chromium (Cr) and Molybdenum (Mo) elements were the main chemical compositions measured in laser cladding layer. The service life of laser remanufacturing plunger was nearly the same as the life of new plunger. However, its remanufacturing cost was only 50% of the new plunger’s. The laser remanufacturing technique is worth for extending and applying due to high cost performance.