ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The electron beam freeform fabrication (EBF3) layer-additive manufacturing processhas been developed to directly fabricate complex geometry components. EBF3 introduces metalwire into a molten pool created on the surface of a substrate by a focused electron beam. Partgeometry is achieved by translating the substrate with respect to the beam to build the part onelayer at a time. Tensile properties have been demonstrated for electron beam deposited aluminumand titanium alloys that are comparable to wrought products, although the microstructures of thedeposits exhibit features more typical of cast material. Understanding the metallurgicalmechanisms controlling mechanical properties is essential to maximizing application of the EBF3process. In the current study, mechanical properties and resulting microstructures were examinedfor aluminum alloy 2219 fabricated over a range of EBF3 process variables. Material performancewas evaluated based on tensile properties and results were compared with properties of Al 2219wrought products. Unique microstructures were observed within the deposited layers and atinterlayer boundaries, which varied within the deposit height due to microstructural evolutionassociated with the complex thermal history experienced during subsequent layer deposition.Microstructures exhibited irregularly shaped grains, typically with interior dendritic structures,which were described based on overall grain size, morphology, distribution, and dendrite spacing,and were correlated with deposition parameters. Fracture features were compared withmicrostructural elements to define fracture paths and aid in definition of basic processingmicrostructure-property correlations
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.519-521.1291.pdf
Permalink
