SAMULET; Project 4: Project 4.3.1: UFG Ti-6Al-4V for Low Temperature/High Productivity DB/SPF and Project 4.3.2: Hot-Die Forging of Titanium Alloys

Several process options for the manufacture of components are beset with either quality or economic deficiencies. For example, the cleanliness of surfaces of aerospace components is critical to the production of sound welds using electron-beam welding technology; deficient cleaning methods would result in defective welds. Again, the conversion of Titanium alloys into aerospace components is currently attended to at temperatures at which tool-materials deteriorate rapidly, incurring a prohibitively high tool cost. Converting aerospace materials at high-temperatures would also require specialised tool-materials that are more expensive to cut and capital expenditure that is, typically, four times greater. Current practice is to shoehorn the controlling parameters to enable the manufacture of components. Continuation in this manner is unacceptable from an economic viewpoint. Considering that component designers need to be sufficiently conversant with the geometrical, functional and manufacturing constraints while evolving the form of the component, it follows that new processes, regardless of whether these relate to surface preparation (cleaning), processing at elevated temperatures or to machining to reduce further surface finishing requirements, may only be adopted efficiently, after the critical controlling parameters have been quantified. Project 4: Novel and Transformed Processes, attends to the quantification of the key controlling parameters. Research in the group of novel and transformed processes is with a view to acquiring the know-how to enable the design of components and the associated processes along the value-adding chain. This group refers to the laser cleaning of aerospace materials and components for subsequent processing, since it is known that several defects arise from the failure to meet quality standards. Two aspects of Project 4 refer to the high-temperature conversion of materials into aerospace components. The first of these refers to a new means of manufacturing components at low temperature by introducing a new form of raw material - this ultra-fine-grained variant enables the operation of the conventional processes (diffusion bonding and super-plastic forming) at significantly reduced temperatures, resulting in reduced manufacturing cost. This fine-grained variant will be manufactured and subjected to component forming exercises to demonstrate the new economic balance in manufacturing aerospace components. The second process is hot-die forging of aerospace components. The current practice of bashing Titanium alloys at very high temperatures into a rough form and then whittle away to arrive at the final form is recognised as being expensive. The need to bash the material arises from the fact that the work-material cools too rapidly to operate at the lower forging speeds that can be attended to in presses of lower capital expenditure. If one were to operate at lower temperatures, smaller presses may be used but this balance between bashing the metal at high temperatures and squeezing the work-material at lower temperatures has yet to be defined. The proposed research will define the parameters critical to operating at lower temperatures. The final project refers to an elegant approach to removing the excess materials remaining on components in a manner that reduces the amount of additional downstream processing of surfaces to meet performance standards. By quantifying the character of the cutting tool and the machine on which excess material is removed, the technology will enable the operation of the metal-removal system in a manner that recognises the fact that the character of both, the cutting tool and the machine-tool influence the cut surfaces. Each separate process will assume a role in more cost-effective conversion of raw materials for the aerospace industrial sector and would also impact on the nuclear and automotive industrial sectors.