Eric A. Nyberg

Development of Ti-6Al-4V and Ti-1Al-8V-5Fe Alloys Using Low-Cost TiH2 Powder Feedstock

Thermo-mechanical processing was performed on two titanium alloy billets, a beta-titanium alloy (Ti1Al8V5Fe) and an alpha-beta titanium alloy (Ti6Al4V), which had been produced using a novel low-cost powder metallurgy process that relies on the use of TiH2 powder as a feedstock material. The thermomechanical processing was performed in the beta region of the respective alloys to form 16-mm diameter bars. The hot working followed by the heat treatment processes not only eliminated the porosity within the materials but also developed the preferred microstructures. Tensile testing and rotating beam fatigue tests were conducted on the as-rolled and heat-treated materials to evaluate their mechanical properties. The mechanical properties of these alloys matched well with those produced by the conventional ingot processing route.

Magnesium Alloys in U.S. Military Applications: Past, Current and Future Solutions

Since the 1940’s Mg-alloys have been used for military applications, from aircraft components to ground vehicles. The drive for usage was primarily availability and lightweighting of military systems. But the promise of widespread military usage was not met largely based on corrosion and flammability concerns, poor mechanical behavior and inferior ballistic response. This review paper will cover historical, current and potential future applications with a focus on scientific, engineering and social barriers relevant to integration of Mg-alloy. It will also present mechanical and physical property improvements solutions which are currently being developed to address these issues.

Magnesium technology 2002, part I: Primary production, environmental issues, high-temperature alloys

ConclusionIt is expected that the research in high-temperature alloy development will reach a critical mass in about five years. This will not only raise the materials science of magnesium to a higher level but will also increase the confidence of the industry in magnesium as a structural performance material. Currently, applications are being actively pursued in United States Council for Automotive Research power train programs and European Council for Automotive R&D engine block programs to develop the technology for elevated-temperature magnesium. More research is still needed in this interesting materials field.

Magnesium Front end Research and Development: A Canada‐China‐USA Collaboration

The Magnesium Front End Research & Development (MFERD) project is an effort jointly sponsored by the United States Department of Energy, the United States Automotive Materials Partnership (USAMP), the Chinese Ministry of Science and Technology and Natural Resources Canada (NRCan) to demonstrate the technical and economic feasibility of a magnesium-intensive automotive front end body structure which offers improved fuel economy and performance benefits in a multi-material automotive structure. The project examines novel magnesium automotive body applications and processes, beyond conventional die castings, including wrought components (sheet or extrusions) and high-integrity body castings. This paper outlines the scope of work and organization for the collaborative (tri-country) task teams. The project has the goals of developing key enabling technologies and knowledge base for increased magnesium automotive body applications. The MFERD project began in early 2007 by initiating R&D in the following areas: crashworthiness, NVH, fatigue and durability, corrosion and surface finishing, extrusion and forming, sheet and forming, high-integrity body casting, as well as joining and assembly. Additionally, the MFERD project is also linked to the Integrated Computational Materials Engineering (ICME) project that will investigate the processing/structure/properties relations for various magnesium alloys and manufacturing processes utilizing advanced computer-aided engineering and modeling tools.

The Microstructure of Rolled Plates from Cast Billets of U-10Mo Alloys

This report covers the examination of 13 samples of rolled plates from three separate castings of uranium, alloyed with 10 wt% molybdenum (U-10Mo) which were sent from the Y-12 National Security Complex (Y12) to the Pacific Northwest National Laboratory (PNNL).

High Shear Deformation to Produce High Strength and Energy Absorption in Mg Alloys

Magnesium alloys have the potential to reduce the mass of transportation systems however to fully realize the benefits it must be usable in more applications including those that require higher strength and ductility. It has been known that fine grain size in Mg alloys leads to high strength and ductility. However, the challenge is how to achieve this optimal microstructure in a cost effective way. This work has shown that by using optimized high shear deformation and second phase particles of Mg2Si and MgxZnZry the energy absorption of the extrusions can exceed that of AA6061. The extrusion process under development described in this presentation appears to be scalable and cost effective. In addition to process development a novel modeling approach to understand the roles of strain and state-of-strain on particle fracture and grain size control has been developed.

Influence of Homogenization on the Mechanical Properties and Microstructure of the U-10Mo Alloy

............................................................................................................................................ iii Acronyms and Abbreviations ...........................................................................................................vii 1.0 Introduction ................................................................................................................................ 1 2.0 Experimental ............................................................................................................................... 2 2.1 Materials ............................................................................................................................. 2 2.2 Homogenization Heat Treatment ....................................................................................... 2 2.3 Compression Testing .......................................................................................................... 3 2.4 Characterization of Microstructure .................................................................................... 4 3.0 Results ........................................................................................................................................ 5 3.1 Homogenization: Microstructure of the As-Cast U-10Mo ................................................. 5 3.2 Mechanical Properties (Compression Testing) .................................................................. 7 3.3 Microstructure of Compression Tested Samples ................................................................ 9 3.3.1 Sample Compression Tested at 500°C .................................................................... 9 3.3.2 Sample Compression Tested at 650°C .................................................................... 9 3.3.3 Sample Compression Tested at 800°C .................................................................. 13 4.0 Discussion ................................................................................................................................. 15 5.0 Summary and Conclusions ....................................................................................................... 16 6.0 References ................................................................................................................................ 17

Development of Magnesium Alloys for High Speed Trains in China

In 1939, Dow Chemical had advertisements discussing the use of magnesium for trains, following their successful use of Dowmetal truck bodies in 1935. Despite the fact that the concept of using magnesium (Mg) alloys in trains has existed for at least 75 years, their remains significant challenges in alloy development and forming technologies before commercial application will find mass application.

A New Magnesium Alloy System: TEXAS

A new TEXAS alloy system (Mg-Sn-Nd-Ca-Al-Si) is presented in order to extend the range of applications for magnesium alloys. The alloy has been produced by permanent mould direct chill casting, a process that provides a homogenous distribution of alloying elements throughout the entire casting. This work presents microstructural features and a new Mg-Sn-Ca phase with the morphology of hexagonal platelets. Additionally mechanical properties and the corrosion behaviour of TEXAS alloys are presented in as cast and heat treated conditions.

Summary of Compression Testing of U-10Mo

The mechanical properties of depleted uranium plus 10 weight percent molybdenum alloy have been evaluated by high temperature compression testing.