Browse Topic: Machining processes
ABSTRACT Today’s combat vehicle designs are largely constrained by traditional manufacturing processes, such as machining, welding, casting, and forging. Recent advancements in 3D-Printing technology offer tremendous potential to provide economical, optimized components by eliminating fundamental process limitations. The ability to re-design suitable components for 3D-printing has potential to significantly reduce cost, weight, and lead-time in a variety of Defense & Aerospace applications. 3D-printing will not completely replace traditional processes, but instead represents a new tool in our toolbox - from both a design and a manufacturing standpoint.
Groove designs presented herein are applicable for use with machined or formed metal seals which are similar in configuration to those shown in figure 3, which operate under internal pressure or in vacuum service and which have been specifically qualified or recommended by the purchaser or the manufacturer for use with this AIR. They are also applicable for use with metal o-rings (e.g., MS9142, MS202 thru MS9205) where interchangeability with machined or formed metal seals is desired. For metal o-ring groove designs where inter-changeability is not a requirement refer to ARP 674.
The aluminum alloy Al7075 is commonly used in aircraft industry due to its high mechanical resistance to weight ratio. Nevertheless when the structure is being serviced upon the severe environmental conditions or loads degradation mechanisms could often been found in the material. To improve its behavior the cold spray process with various titanium powders (e.g. CP Ti, Ti-64) deposited onto Al7075 was investigated. The spraying of angular titanium powder was performed in the presence of nitrogen and helium supplied at process parameters (temperature, pressure), which were the maximum values attainable by the CS system used. The deposits were sprayed while maintaining a standoff distance in the range from 20 to 100 mm increased by 10 mm. The experimental data indicated that the deposition efficiency had increased significantly with increasing standoff distance. The coating porosity first decreased to minimum 0.6% and then increased significantly to 9.8%. The mechanical properties of the coatings reached the highest values when the porosity was minimum. No new phases were reported in the cold sprayed titanium coatings when compared with the starting feedstock. The same process parameters were transferred to Ti- 6Al-4V coral like powder deposition process. The shear strength between Ti coating material and Al7075 substrate was measured. Additionally the tensile strength of the deposit only, previously disintegrated from the substrate, was checked out. The data obtained indicate that the consolidation of Ti powder with Al7075 substrate made by cold spray could be served for both: materials integration and building a component by materials disintegration, where Al substrate is removed on spraying and machining; and simply used as a technological support for additive manufacturing of a self-standing real life component.
Additive manufacturing (AM) is a novel process of fabricating components in a layer-by-layer method under the control of computer-aided design (CAD) information, rather than by the traditional use of casting molds and forming dies. By allowing for net-shape fabrication of highly complex geometries without molds or machining, this process offers the potential to reduce material usage, energy consumption, component cost, and fabrication time. While AM presents the unique opportunity to manufacture single components quickly, it also provides for the potential to examine the effects of individual design alterations on overall system performance. QuesTek has utilized its proven Integrated Computational Materials Engineering (ICME) methodology to adapt Ferrium® C64® steel for additive manufacturing, where the market availability of AM gear steels is very limited. QuesTek has demonstrated success in AM-processing of C64 using a laser-based powder bed technique, from procurement of powder through final test part fabrication. This production route is demonstrating the ability to fabricate a near-net shaped part at a reduced cost and significantly reduced lead time relative to conventional manufacturing routes, making it especially useful for rapid prototyping of new components.
Items per page:
50
1 – 50 of 631