Effect of Laser Power and Powder Morphology on Surface Roughness of TI6Al4V Produced by Laser Powder-Directed Energy Deposition

Additive manufacturing of metals has emerged as a technology capable of producing complex metal parts in the “near net shape” format, performing repairs, and creating components with gradient material, enabling manufacturing parts with high added value and low production. Directed Energy Deposition from Laser and Powder (LP-DED) is one of the categories of the additive manufacturing process by which concentrated thermal energy allows the metallic powder to melt. These applications have been attractive to different areas such as aerospace, automotive, and medical. In the medical field, its application has focused on creating implants, prostheses, instruments, and medical devices. Ti6Al4V titanium alloys have stood out due to their high mechanical strength, high corrosion resistance, low density, and good biocompatibility. One of the literature challenges reflects the roughness given to printed parts by the LP-DED process, which can affect the osseointegration of prostheses and implants, linked to their recovery time and success. This article evaluates the roughness of Ti6Al4V parts obtained from the LP-DED process using two types of powder. The first is produced by gas atomization, and the second by advanced plasma atomization. Subsequently, eight specimens were fabricated by LP-DED on pure Ti substrate. The laser power was another input variable ranging from 300 W to 345 W with a 15 W increment. The samples were cleaned with deionized water and acetone using ultrasonic vibration. Then, we evaluated the roughness of the samples using a confocal microscope. The roughness evaluation shows that a particle size distribution with Gaussian behavior, as demonstrated by AP&C, resulted in a coarser roughness. In contrast, the Carpenter Additive powder resulted in a slightly thinner roughness. The Laser Power influenced the surface quality due to the increment of density energy. The results obtained in this article represent a breakthrough in medical implants, offering solutions that enable surface integrity and osseointegration, improving the rehabilitation process and increasing the quality.