Critical instability at moving keyhole tip generates porosity in laser melting

Abstract

The formation of “keyholes” (vapor-filled depressions) during additive manufacturing leads to porosity, which degrades alloy performance, especially fracture properties, and remains a big challenge for the 3D printing of metals. Zhao et al. used high-speed x-ray imaging to take a detailed look at how keyhole formation connects to porosity in a titanium alloy. They found that instability at the keyhole tip drives pores away to get trapped in the solidification front. Understanding this process and the operating parameters under which it occurs provides a roadmap for avoiding porosity and building high-quality metal parts.

Document Details

Document Type
Pub Defense Publication
Publication Date
Nov 27, 2020
Source ID
10.1126/science.abd1587

Entities

People

  • Anthony D Rollett
  • Cang Zhao
  • Kamel Fezzaa
  • Niranjan D Parab
  • Tao Sun
  • Wenda Tan
  • Xuxiao Li

Organizations

  • Argonne National Laboratory
  • Carnegie Mellon University
  • National Aeronautics and Space Administration
  • National Science Foundation
  • Tsinghua University
  • United States Department of Defense
  • United States Department of Energy
  • University of Utah
  • University of Virginia

Tags

Fields of Study

  • Materials science

Readers

  • Electronics Engineering
  • Fluid Dynamics.
  • Powder metallurgy of Titanium alloys.

Technology Areas

  • Directed Energy