Causes of failure and repairing options for dies and molds: A review

The life of industrial dies and molds can be efficaciously increased by timely repair of damaged surfaces. The degree and severity of damages of these vital production tools depend on the service conditions and requisite precision in shape and size of dies and molds. The failure analysis of these damaged surfaces is important for the selection of most appropriate process and processing parameters leading to longer mean time between failures. This paper comprehensively depicts the global scenario of the dies and mold industries, various materials used for manufacturing of dies and molds, their modes of failures under different duty conditions and various repairing options. The global market of dies and molds is more than a hundred billion US dollars with wide spread in BRIC nations, European Union and North America. Various designations of tool steels with/without surface treatment and aluminum alloys are used for the manufacturing of dies and molds. The major causes of failures during operations are due to high thermal shocks, mechanical strain, cyclic loading and corrosion resulting in heat checking, wear, plastic deformation and fatigue. Other cause failures are due to faulty design, defective material, mishandling and force majeure due to accidental conditions. These issues are traditionally repaired using gas tungsten arc welding, electro-spark and cold spray technique depending on the material. Laser, electron beam and micro-welding are recent repairing options attractive mainly due to low heat input and controlled material deposition. The comprehensive study presented in this paper is relevant to the die and mold repairing industries and will assist the selection of the most appropriate process depending upon the availability of resources with thorough knowledge of the advantages and limitations.