CoA. Memoranda
Permanent URI for this collection
Browse
Browsing CoA. Memoranda by Author "Apps, R. L."
Now showing 1 - 4 of 4
Results Per Page
Sort Options
Item Open Access Final report of grit blasting and metal spraying trials carried out at H. M. Dockyard, Devonport(College of Aeronautics, 1966-03) Apps, R. L.Mild steel surfaces that are to be protected by aluminium or zinc spray coatings are generally prepared by blasting with chilled iron angular grit. Previous work1had shown that a relationship exists between the grit blasting conditions (at least in terms of blasting angle and grit condition), the reflectivity of the blasted surface and the bond strength of a spray coating of aluminium on the blasted surface. An instrument has been developed that assesses the suitability of a blasted surface for subsequent spraying by measuring the reflectivity and has proved reasonably successful under laboratory conditions. The present need is to ascertain the performance of this reflectivity meter under shop and site conditions. The opportunity to carry out such tests at H.M. Dockyard, Devonport, was offered by the Ministry of Defence and a series of tests was made on 16th June, 1965.Item Open Access Progress report to sponsors in the surfacing division, The Welding Institute(College of Aeronautics, 19) Apps, R. L.Since the last report to sponsors circulated in mid-1967, considerable concern has been felt over the wide scatter of results. The scatter in results between specimens produced in a single batch was generally comparatively small, in the order of 15%, but occasional results occurred which ehow6d much greater differences from the average. Identical experiments carried out in different batches exhibited rather more scatter than with in single batches. Similar scatter was noted in the results of other workers" 2 . Additionally, many blasting variables which had previously been considered important by metal sprayers appeared to have very little effect on the bond strength of flame sprayed aluminium coatings on mild steel. Consideration of scatter in results suggested four possible reasons for this scatter.Item Open Access The use of process selection exercises for the training of welding technologists(College of Aeronautics, 1967) Apps, R. L.Formal lectures and laboratory experiments do not give students sufficient experience of welding processes applied to specific fabrications. A series of designs has been evolved which ib.capable of being fabricated by several different methods and students are required to produce fabrication procedures for each design. Suggested procedures are then discussed in an open forum in which both staff and students participate. The use of these exercises has been found to be a useful method whereby course members can pass on their own experience to other students and in which students learn to make decisions based on available, but often incomplete, facts.Item Open Access Welding in aircraft structures(College of Aeronautics, 1966) Apps, R. L.; Gourd, L. M.; Jubb, J. E. M.The welding processes relevant to the welding of aircraft materials are briefly reviewed, together with those materials of present or future interest for aircraft structures. The problems of design for welding are also considered. It is concluded that the prospects for welding are more premising in materials other than light alloys, which win be used for high speed aircraft. In addition, further development of automatic welding machines and large heat treatment facilities is needed.