Laser welding of metallic glass to crystalline metal in laser-foil-printing additive manufacturing

"The application of metallic glasses has been traditionally limited to parts with small dimensions and simple geometries, due to the requirement of fast cooling during the conventional process of casting. In addition, joining metallic glass to crystalline metal is of interest for many applications that require locally tailored functions and properties, but it is challenging. This research describes a promising additive manufacturing technology, i.e., laser-foil-printing, to make high-quality metallic glass parts with large dimensions and complex geometries and to fabricate multi-material components from metallic glass and crystalline metal. In this research, Zr_52.5Ti₅Al₁₀Ni_14.6Cu_17.9 metallic glass parts are fabricated on different crystalline metal substrates, including pure Zr metal, Ti-6Al-4V alloy, and 304L stainless steel. The dissimilar bonding between the metallic glass part and the crystalline metal substrate is studied and then improved through the use of appropriate intermediate layers. The microstructure and properties of the fabricated metallic glass parts are also investigated. The results show that Zr can form a crack-free bonding with Zr-based metallic glass owing to the formation of ductile α-Zr phase, whereas direct joining of Zr-based metallic glass to Ti alloy or stainless steel fails due to the formation of various brittle intermetallic compounds. By using Zr intermediate layers for Ti substrates and V/Ti/Zr intermediate layers for stainless steel substrates, the formation of deleterious intermetallics is suppressed and thus the bonding between metallic glass and crystalline metal is significantly improved. Additionally, fully amorphous and nearly fully dense (~99.9%) metallic glass parts with comparable mechanical properties to as-cast parts have been successfully fabricated"--Abstract, page iv.

Name thesis:degree_name

Ph. D. in Mechanical Engineering

Grantor

Missouri University of Science and Technology

Author dc:creator

• Li, Yingqi

• Mechanical Engineering

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/2784

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-3789