Repair of Inconel 718 parts by Cold Spray Additive Manufacturing: The effect of substrate preheating on thick coatings properties

Cold spray additive manufacturing (CSAM) has been developed as a promising solid-state technology for repair applications. Yet, one of the main challenges of CSAM is the deposition of high-strength materials, such as Inconel 718® (IN718), due to their low particle plasticity. IN718 is a high-performance Ni-based superalloy usually used in relevant applications such as high-temperature industries or jet engines. The interest in remanufacturing IN718 damaged parts with CSAM has increased in the last years; however, different deposition strategies still need to be studied to obtain well-bonded and dense IN718 deposits. This study investigates the effect of IN718 substrate preheating on the CSAM IN718 deposit microstructure and thickness, as well as the adhesion mechanisms and strength at room and preheating temperatures: 250 and 400 ºC. The results revealed that a substrate preheating temperature of 400 ºC promoted a dense microstructure within a 1.2 mm thick coating with porosity values < 0.1 %, and an adhesion strength > 50 MPa.