Porous γ-TiAl Structures Fabricated by Electron Beam Melting Process

Abstract

Porous metal structures have many benefits over fully dense structures for use in bio-implants. The designs of porous structures can be made more sophisticated by altering their pore volume and strut orientation. Porous structures made from biocompatible materials such as titanium and its alloys can be produced using electron-beam melting, and recent reports have shown the biocompatibility of titanium aluminide (γ-TiAl). In the present work, we produced porous γ-TiAl structures by electron-beam melting, incorporating varying pore volumes. To achieve this, the individual pore dimensions were kept constant, and only the strut thickness was altered. Thus, for the highest pore volume of~77%, the struts had to be as thin as half a millimeter. To accomplish such fine struts, we used various beam currents and scan strategies. Microscopy showed that selecting a proper scan strategy was most important in producing these fine struts. Microcomputed tomography revealed no major gaps in the struts, and the fine struts displayed compressive stiffness similar to that of natural bone. The characteristics of these highly-porous structures suggest their promise for use in bio-implants.

On the Formation Mechanism of Banded Microstructures in Electron Beam Melted Ti–48Al–2Cr–2Nb and the Design of Heat Treatments as Remedial Action

“…[ 3,9,19,21 ] Mechanical properties of TiAl parts remain highly microstructure‐sensitive, [ 8 ] which makes clarifying the processing‐microstructure–property relationship a necessity. Several different additively manufactured TiAl alloys were already investigated, such as the aforementioned Ti–(47–48)Al–2Cr–2Nb alloy, [ 3,21–42 ] or the TNM alloy, [ 43–45 ] as well as high Nb bearing TiAl alloys. [ 46–52 ] Many different microstructures of these various electron beams melted titanium aluminide alloys were reported, generally fine‐grained.…”

Influence of the electrolyte’s pH on the properties of electrochemically deposited hydroxyapatite coating on additively manufactured Ti64 alloy

“…Corresponding design files were prepared using a software package Solid Works (by Dassault Systems) and prepared for printing using an ARCAM Build Assembler. More detailed descriptions of the corresponding procedures can be found in the literature 66 , 67 .…”

Study on Inclusions Distribution and Cyclic Fatigue Performance of Gear Steel 18CrNiMo7-6 Forging

“…As a necessary transmission part of mechanical equipment, different kinds of high-alloy gears have been widely applied and popularized in industrial production to meet the requirements of aerospace, metallurgical manufacturing, automobile production, mining, lifting transportation and building materials machinery, etc. [1,2]. Among them, the application of 18CrNiMo7-6 according to the standard of DIN (German Institute for Standardization) in Germany has become increasingly widespread with the expansion of high-alloy gear steel production, and the predecessor of this steel is 17CrNiMo6 gear steel [2].…”

“…[1,2]. Among them, the application of 18CrNiMo7-6 according to the standard of DIN (German Institute for Standardization) in Germany has become increasingly widespread with the expansion of high-alloy gear steel production, and the predecessor of this steel is 17CrNiMo6 gear steel [2].…”