Additive Manufacturing (AM) which also known as metal 3D printing technique is a promising process with a massive potential for developing a component for wide range applications for various industries such as automotive, aerospace, power plants, etc.  Recently, AM technique was introduced to the nuclear power plant industry as AM is capable to manufacture the substitution of aging and obsolete component. However, the Additive manufactured component has inferior mechanical properties and performance in terms of fatigue strength and wear resistance compared to its conventionally manufactured counterpart. Ultrasonic Nanocrystal Surface Modification (UNSM) is one of mechanical surface modification technique which known for improving fatigue strength and wear resistance of wrought material. Hence, in this study effect of UNSM on fatigue strength and wear resistance of additive manufactured material was investigated. The investigation was done to Ni Alloy 718 (UNS N07718) as this material is used for nuclear power plant components and was manufactured with two different AM techniques namely, Laser Powder Bed Fusion (PBF) and Laser Direct Energy Deposition (DED). The evaluation was conducted by comparing the specimens as printed condition and UNSM treated specimens for each AM technique by performing fatigue and tribo-test. The initial experiment result of fatigue test showed that UNSM treatment successfully increased the fatigue strength of PBF manufactured specimens by more than 20 % and it was expected that it can reach the fatigue strength level of wrought material. The experiment results are also compared to untreated and UNSM treated wrought UNS N07718 material experiment data as the benchmark to analyze the performance improvement by UNSM treatment. The factor that affected performance improvement by UNSM and failure mechanisms are discussed. This result will become a part of the technical basis for KEPIC Code Case development.

 

Keywords:  Fatigue Strength, Wear Resistance, AM (Additive Manufacturing), UNSM (Ultrasonic Nanocrystal Surface Modification), PBF (Powder Bed Fusion), DED (Direct Energy Deposition), UNS N07718


Increasing Fatigue Strength and Wear Resistance of Additive Manufactured Nickel Alloy (Uns N07718) by Ultrasonic Nanocrystal Surface Modification (Unsm) Treatment

Division / Sponsors: 
Pressure Vessels & Piping (PVP)


Paper Proceedings: https://asmedigitalcollection.asme.org/PVP/PVP2020/volume/83815

PVP2020 - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.