FIGURE 4-11 Continuous improvement in materials for the Ford F-150. MS, martensitic steel; HSS, high-strength steel; AHSS, advanced high-strength steel; UHSS, ultra high-strength steel. SOURCE: Bruno Barthelemy, Ford Motor Company, “Lightweight Technologies,” presentation to the committee, October 2010.
- Lightweighting of land-based vehicles has been pursued as a means to facilitate air transport capability for rapid deployment, improve fuel economy, more readily cross open-water barriers, and enhance battlefield mobility and speed.
- Using aluminum alloys as primary hull materials for protection in tactical vehicles has proven effective in meeting many vehicle requirements, including speed, maneuverability, and survivability against some threats.
- Aluminum alloy hulls have not been able to provide the desired protection against the most lethal threats. The ever-increasing level of threat from RPGs, EFPs, shaped charges, mines, and IEDs has forced “up-armoring” across the various classes of land-based combat vehicles, with a concomitant increase in weight.
- Titanium and magnesium have properties that could greatly advance lightweighting, but there are many barriers to their utilization. Titanium is very expensive to extract. Magnesium is in short supply domestically and is also more expensive to form into useful product shapes than is aluminum or steel. Before either material can be widely used in lightweighting, new manufacturing technologies are needed to improve weldability, formability, spall resistance, fatigue resistance, and (particularly for titanium) susceptibility to corrosion in marine environments.
- The requirement for competitive prototyping (or, with a waiver, for a single prototype) prior to the engineering and manufacturing development phase can, in some instances, inhibit the use of new materials and new designs by not allowing adequate time for testing and validation.
- Because of the great emphasis on soldier protection as well as the pressures to control costs, lightweighting of land-based combat vehicles has proven to be more challenging than that of air and sea vehicles. Thus, it is not surprising that, apart from aluminum-based alloys, few new materials have found their way into extensive implementation in land-based vehicles.