Low-cost Titanium: 'Affordable Ti': Poster Session
Sponsored by: TMS Structural Materials Division, TMS: Titanium Committee, TMS: Powder Materials Committee
Program Organizers: Ramana Reddy, University of Alabama; M. Ashraf Imam, George Washington University
Tuesday 5:30 PM
February 25, 2020
Room: Sails Pavilion
Location: San Diego Convention Ctr
Session Chair: Ashraf Imam, George Washington University; Ramana Reddy, The University of Alabama
Cancelled
M-62: Direct Fabrication of Strong and Ductile Ti-6Al-4V Alloy by Hot Pressing of the Machining Swarf: Fei Yang1; 1Waikato University
Ti-6Al-4V (Ti-64) swarf is produced every day in commercial operations but its direct use for the fabrication of strong and ductile Ti-6Al-4V alloy is seldom reported. This study consolidated as-received Ti-64 swarf into near fully dense Ti-6Al-4V alloy by hot pressing. The microstructures and tensile mechanical properties of the hot-pressed Ti-64 alloy and the effect of subsequent solution treatment and ageing (STA) were studied. Tensile test showed that the swarf-Ti64 alloy achieved a yield strength (YS) of about 900MPa, ultimate strength (UTS) of about 1000MPa, and strain-to-fracture of over 8%. After STA, both of the YS, UTS and the strain-to-fracture were significantly improved. Our research suggest that it is feasible and cost-effective to directly consolidate Ti-6Al-4V swarf into strong and ductile Ti-6Al-4V alloy by hot pressing for a variety of potential applications.
M-63: Effect of Sintering Temperature on Mechanical and Tribological Behavior of Ti-Ni Alloy for Biomedical Applications: Fellah Mamoun1; Hezil Naouel1; Touhami Mohammed Zine2; Mohamed Abdrabou Hussein3; Alex Montagne4; Alberto Mejias4; Alain Iost4; Stephania Kosman4; Timofey Chekalkin5; Aleskei Obrosov6; Sabine Wiess6; 1Abbes Laghrour University; 2Tribology and Materials Group, Laboratory of Foundry, BADJI Mokhtar University BO; 3KFUPM; 4LABO MSMP Ecole Nationale Superieur Arts et Metiers Paris Tech Lille; 5Research Institute of Medical Materials, Tomsk State University; 6Department of Physical Metallurgy and Materials Technology, Brandenburg Technical University
Hot Isostatically Pressed (Ti-Ni) samples are prepared by subjecting them to different sintering temperatures ranging from 750 to 1150 °C. Wear tests were conducted using a ball-on-plate type Oscillating tribometer, under different applied loads of 2, 8, and 16 N respectively. The morphological characterization indicated that the mean pore, and crystallite size continuously decreases with increasing sintering temperature to reach the lowest value at 1150 °C, respectively. The relative density of the 1150 °C sintered sample is as high as 98.0 %. Moreover, the higher sintering temperatures lead to the higher relative density and the greater hardness and young modulus of the sample. Both the friction coefficient and wear rate were lower in the samples sintered at 1150 °C. This improvement in friction and wear resistance is attributed to the grain refinement and closed porosity. The Ti-Ni sintered at 1150 °C showed good tribological performance under all test conditions
Cancelled
M-64: Powder Metallurgy Fabrication, Microstructures and Tensile Mechanical Properties of Low Cost and High Performance Ti and Ti-6Al-4V Alloy Parts and Structural Members: Deliang Zhang1; Yifeng Zheng2; Rui Wang1; Junkun Yue1; Yifei Luo2; Hongzhi Niu1; Jiamiao Liang2; 1Northeastern University; 2Shanghai Jiao Tong University
Starting with TiH2 powder and through powder compact forging, powder compact extrusion, powder compact extrusion-forging as well as in-situ dehydrogenation, nearly fully dense Ti and Ti-6Al-4V (wt%) alloy near-net shaped parts and structural members are produced. They exhibit either fine fully lamellar alpha or alpha/beta structure or fine a plates mixed with nanometer scale betatransformed structure. Together with a relatively high oxygen content of around 0.4wt%, they show excellent combinations of high strength and good tensile ductility. The low energy consumption associated with fully solid-state processing and shaping and simplified and short process ensure low processing cost from raw material to near-net shaped of net-shaped products. The nearly-full density and fine and uniform microstructure render the parts and structural members with excellent mechanical properties. This route of producing low cost and high performance titanium and titanium alloy parts has a high potential of being used by industry.
Cancelled
M-65: Refinement of PEG/PMMA Binder Systems for Metal Injection Molding of Titanium: Peng Cao1; Muhammed Hayat1; 1University of Auckland
Binder systems based on Polyethylene glycol (PEG) and poly methyl methacrylate (PMMA) can cause voids formation in metal injection molded parts because of PEG re-crystallisation upon cooling. The characteristics of such voids are typical of wormhole type defects. As reported previously, polyvinylpyrrolidone (PVP) can be used as an effective inhibitor of PEG crystallization, thereby reducing voids formation in the PEG/PMMA feedstocks. However, the addition of PVP leads to longer cooling times during injection molding operation. To counter this, an additional polymer, polyvinyl acetate (PVAc) has been incorporated into the PEG/PMMA binder system in this research. To find out the effective concentration of PVAc, differential scanning calorimetry (DSC) studies were carried out, followed by injection molding and rheological properties analysis. The results show that the addition of 10 wt% PVAc into the PEG/PMMA binder system produces Ti-MIM feedstocks with good workability and void-free injection molded samples.