DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Controlling melt flow by nanoparticles to eliminate surface wave induced surface fluctuation

Journal Article · · Additive Manufacturing
 [1];  [1];  [1];  [1];  [1];  [2];  [1];  [3];  [1]
  1. Univ. of Wisconsin, Madison, WI (United States)
  2. Argonne National Lab. (ANL), Lemont, IL (United States)
  3. Argonne National Lab. (ANL), Lemont, IL (United States); Univ. of Virginia, Charlottesville, VA (United States)

The high surface roughness is one of the major challenges encountered in laser metal additive manufacturing (AM) processes, which is closely related to the melt flow behavior. However, how to control the melt flow in laser metal AM processes to improve surface finish is unknown. Here we reveal the effects of nanoparticles on melt flow behavior at every location of melt pool during laser metal AM process for the first time using Al6061 + TiC nanoparticles system and achieve significant improvement of surface finish by using TiC nanoparticles to control the melt flow and damp the surface wave. Based on the in-situ x-ray imaging observation, the surface wave is fully damped after adding TiC nanoparticles, compared with only 56% damping without nanoparticles during LPBF of Al6061. Our in-depth in-situ x-ray imaging analysis and viscosity measurement enable us to identify that nanoparticle-induced increase of viscosity causes the fully damping of the surface wave by (1) increasing the internal fluid friction for more efficient wave amplitude reduction, (2) controlling the melt flow to increase the surface wave number, (3) controlling the melt flow to increase the wave damping time. Furthermore, we also quantified the relative contributions of increasing fluid friction, increasing wave number, and increasing damping time to wave damping, which account for 61%, 25%, and 14%, respectively. Furthermore, our research provides the mechanisms and potential method to address the surface finish challenge in laser metal AM processes.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
National Science Foundation (NSF); USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division
Grant/Contract Number:
AC02-06CH11357
OSTI ID:
1894651
Journal Information:
Additive Manufacturing, Journal Name: Additive Manufacturing Journal Issue: A Vol. 59; ISSN 2214-8604
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (39)

Surface Modification of Ti6Al4V Open Porous Structures Produced by Additive Manufacturing journal April 2012
Laser polishing of aluminum by remelting with high energy pulses journal July 2015
Research on formation and stability of keyhole in stationary laser welding on aluminum MMCs reinforced with particles journal January 2013
Experimental analysis of applicability of a picosecond laser for micro-polishing of micromilled Inconel 718 superalloy journal November 2013
Review on mechanism and process of surface polishing using lasers journal March 2019
Casting-Based Production of Al-TiC-AlB2 Composite Material Through the Use of KBF4 Salt journal April 2010
The Influence of As-Built Surface Conditions on Mechanical Properties of Ti-6Al-4V Additively Manufactured by Selective Electron Beam Melting journal January 2016
Optical constants and spectral selectivity of titanium carbonitrides journal January 1982
Laser powder-bed fusion additive manufacturing: Physics of complex melt flow and formation mechanisms of pores, spatter, and denudation zones journal April 2016
Transient dynamics of powder spattering in laser powder bed fusion additive manufacturing process revealed by in-situ high-speed high-energy x-ray imaging journal June 2018
High-speed X-ray investigation of melt dynamics during continuous-wave laser remelting of selective laser melted Co-Cr alloy journal January 2019
Influence of defects, surface roughness and HIP on the fatigue strength of Ti-6Al-4V manufactured by additive manufacturing journal December 2018
The influence of additive manufacturing processing parameters on surface roughness and fatigue life journal July 2019
Physics of humping formation in laser powder bed fusion journal March 2020
Laser polishing of parts built up by selective laser sintering journal October 2007
Laser polishing of tool steel with CO2 laser and high-power diode laser journal January 2010
Rapid fabrication of bulk-form TiB2/316L stainless steel nanocomposites with novel reinforcement architecture and improved performance by selective laser melting journal September 2016
Surface roughness analysis, modelling and prediction in selective laser melting journal April 2013
Abrasive flow machining of laser powder bed-fused parts: Numerical modeling and experimental validation journal November 2019
In situ measurements of layer roughness during laser powder bed fusion additive manufacturing using low coherence scanning interferometry journal September 2018
Direct laser sintering of iron–graphite powder mixture journal October 2004
Polishing Titanium- and Nickel-based Alloys using Cw-Laser Radiation journal January 2013
Additive manufacturing of metallic components – Process, structure and properties journal March 2018
Laser Polishing of Additive Manufactured Superalloy journal January 2018
Effect of SiC particles on the laser sintering of Al–7Si–0.3Mg alloy journal July 2008
Nanoparticle-induced unusual melting and solidification behaviours of metals journal January 2017
Pore elimination mechanisms during 3D printing of metals journal July 2019
Aluminum with dispersed nanoparticles by laser additive manufacturing journal September 2019
Controlling process instability for defect lean metal additive manufacturing journal February 2022
Scientific, technological and economic issues in metal printing and their solutions journal July 2019
Control of fluid dynamics by nanoparticles in laser melting journal March 2015
Thermal evolution behavior and fluid dynamics during laser additive manufacturing of Al-based nanocomposites: Underlying role of reinforcement weight fraction journal December 2015
Towards a self-consistent model of the keyhole in penetration laser beam welding journal March 1993
A three-dimensional sharp interface model for self-consistent keyhole and weld pool dynamics in deep penetration laser welding journal December 2010
Feature-based characterisation of signature topography in laser powder bed fusion of metals journal March 2018
Mechanisms of Spiking and Humping in Keyhole Welding journal March 2012
Analytical and Experimental Investigation of Thermocapillary Flow in Pulsed Laser Micropolishing journal April 2014
Keyhole threshold and morphology in laser melting revealed by ultrahigh-speed x-ray imaging journal February 2019
Algorithm for the determination of intrinsic optical constants of metal films: application to aluminum journal January 1995