Session: 03-02-03: Applied Innovations in Solid-State Processes and Surface Engineering: Technologies for Advanced and Sustainable Manufacturing III

Paper Number: 167142

Exploring Electroless Nickel Plating Applications on Additively Manufactured Metal Components: As-Built, Chempolished (CP), and Electropolished (EP) Surfaces 

ABSTRACT
Additive manufacturing (AM) has revolutionized the design and production processes of goods, enabling the creation of components with complex geometries that were formerly difficult or unfeasible to manufacture, and may now be all produced with exceptional precision. Nevertheless, current additive manufacturing (AM) technologies still produce metal components with a coarse surface that generally display fatigue properties, leading to component failure and unfavorable friction coefficients on the printed part. Minor fissures that develop on coarse surfaces within areas of elevated surface roughness serve as stress concentrators or sites for crack initiation. The direct utilization of as-manufactured additive manufacturing (AM) components is constrained and achieving a smooth flat surface poses demanding and complex difficulties. Consequently, post-processing of components created using additive manufacturing (AM) is necessary for enhancing the surface quality of the fabricated parts. This study explores post-processing techniques for additive manufacturing (AM) stainless steel, focusing on electroless nickel plating, ChemPolishing (CP), and ElectroPolishing (EP), both separately and in combination. ChemPolishing (CP) is a versatile method that may be applied to both metal and non-metal elements and uses a very acidic solution as an electrolyte when there is no power source. The high-stress concentration and crack nucleation zone are anodized and dissolved by the solution as the sample is submerged in the bath. ChemPolishing (CP) is a highly successful method of removing stains, oxides, and surface impurities because it produces a homogeneous and smooth surface. It is a recommended technique for improving the material's overall appearance since it provides a polished and attractive finish, and in certain conditions, ChemPolishing (CP) can help increase corrosion resistance. In the other hand, the ElectroPolishing (EP) process utilize highly concentrated acidic electrolytes and DC electric current in a closed circuit. Electrons go from the anode (sample) to the cathode (electrode) because of the power supply during operation, continuously dissolving the sample in the electrolyte. ElectroPolishing (EP) removes small peaks, flaws, and scratches from the surface to efficiently smooth it. It also performs very effectively in removing impurities and imbedded particles, improving the material's cleanliness. Moreover, ElectroPolishing (EP) greatly increases surface brightness and helps to improve corrosion resistance. ElectroPolishing (EP) achieves high material removal rates but may lack of consistency. The incorporation of electroless coating offers the potential for supplementary improvements in the post-processing of ChemPolished (CP) and ElectroPolished (EP) additive manufactured (AM) components, performing an outstanding function in surface modification and engineering applications. Analogous to ChemPolishing (CP), electroless nickel plating is mostly independent of the additive manufactured (AM) component geometry and does not require power source. Wear and scratch resistance are improved by nickel plating on additive manufacturing (AM) products. To optimize nickel deposition, medium-phosphorus (6–9%) ONE PLATE 1001 solution, and high-phosphorus (10–13%) ONE PLATE 2001 solution, phosphorus nickel was tested using the L9 Taguchi design of experiments (TDOE).
Mechanical properties, including scratch resistance and adhesion, were evaluated using the TABER 5900 reciprocating abraser apparatus a 5 N scratch test and ASTM B-733 thermal shock method. Surface analysis was conducted with the KEYENCE VHX-7000 digital microscope, a fully automated system capable of capturing high-resolution images up to 6000x magnification. Chemical composition was assessed via the ThermoFisher Phenom XL SEM, both before and after nickel deposition under optimal conditions. Optimal processing conditions, determined using Qualitek-4 software, revealed improvements in both surface finish and mechanical robustness. This comprehensive analysis underscores the potential of nickel-coated additive manufacturing (AM) parts for enhanced performance, offering a pathway to more durable and efficient additive manufacturing (AM) applications.
Keywords: Taguchi design of experiments, additive manufacturing, chem polishing, electropolishing, electroless nickel plating, hardness, crack nucleation, fatigue, surface finish, acidic electrolytes.

Presenting Author: Pablo E. Sanchez Guerrero University of the District of Columbia

Presenting Author Biography: With over 25 years of diverse experience in industrial and civil engineering, I currently serve as the Laboratory Manager at the University of the District of Columbia (UDC) in Washington, D.C. My academic journey includes a Bachelor's degree in Industrial Engineering from the Universidad Nacional Experimental del Táchira, Venezuela, a Bachelor's in Civil Engineering and a Professional Science Master's in Water Resources Management from U.S. institutions, a Master of Science in Civil Engineering, and I am presently a Doctoral Candidate in Computer Science and Engineering at UDC.

Professionally, I have held progressively responsible positions in production management, maintenance, operations standardization, and project planning and control across various industries, including food, plastics, hydroelectric power, automotive, construction, and agriculture, in both Venezuela and the United States. My expertise encompasses traditional manufacturing processes such as casting (injection molding), forming (forging, rolling, extrusion), joining (welding, soldering, fastening, epoxying), and secondary processes like machining (turning, boring, milling, grinding), as well as surface treatments including heat treatments and thin coatings.

At UDC, I have been instrumental in the installation and operational support of the EOSINT M280 Metal 3D Printer, collaborating closely with EOS GmbH. I provide training and support to both undergraduate and graduate students in operating and maintaining this advanced equipment. Additionally, I have contributed to community projects, such as producing 3D-printed face shields for the DC Government during the COVID-19 pandemic and have supported various senior capstone projects in the machine shop, including the restoration and startup of the CNC Milling Machine GANESH GBM-2616. My teaching responsibilities extend to laboratory classes in Geotechnical Engineering, Concrete, Hydrology and Hydraulics, ThermoFluid, Solid Mechanics, and Structural Engineering.

I am committed to upholding strong work ethics, technical proficiency, integrity, and teamwork. My adaptability and eagerness to embrace new challenges have been key to my professional growth and contributions to the engineering field.

Authors:

Pablo E. Sanchez Guerrero University of the District of Columbia
Pawan Tyagi University of the District of Columbia
Devdas Shetty University of the District of Columbia