Sustainable methodology of conserving historic military vehicles.

Abstract

Research was conducted to analyse corros ion and tribological failures in The Tank Museum Bovington military tanks . Due to the age of the exhibits corrosion of vital components has become a significant issue, it is vitally important to preserve these artefa cts for future generations and so to do this effectively we need to monitor and reduce this corrosion as far as realistically possible. A case study of the historic military tanks followed by experimental research analyses is presented. Structural degradat ion through corrosion and engine wear has been i dentified and analysed . Materials were processed/manufactured during 2 nd Wor ld War, their composition was unknown. Therefore state - of - the - art characterisation techniques were performed on samples collected fr om the M10, Sherman, Centaur and Tiger 1 to obtain material compositions and to identify nearest standards . A bench mark of material loss due to corrosion so far, has been achieved in the M10, Sherman, Centaur, BT – R 60 and King Tiger t h rough ultrasonic c orrosion mapping . Material loss because of corrosion was high in the Centaur in comparison to the Sherman, M10, BT R – 60 and King Tiger s amples. C orrosion analyses techniques were conducted on samples from three tanks the M10, Sherman and Centaur to investigate corrosion m orphology on the tanks surfaces and corrosion propagation from surface to sub - surface level . During this experimental work various corrosion contaminants, sub - surf ace crack s and defects were identified. Corrosion layer/ residues we re relatively thick (approximately 250 μ m) on the surfaces of the M10, wherea s the phenomenon of corrosion pits was wide spread in the Centaur. C orrosion was influenced by the presence of surface contaminants and sub - surface defects such as slags, sulphide inclusions and corrosive pits. These factors alone and/o r in combination were observed to be a serious issue in limiting vehicles‟ longevity. Study of the environments both inside and outside the museum has been conducted to relate corrosion activity wit hin the conte xt. Based upon the data gathered simulated environmental corrosion tests were conducted to quantify corrosion accumulation under a controlled museum environment suitable for the museum visitors. Some degree of corrosion build - up was observed o n the samples under cont rolled environments. Prohesion test was conducted to evaluate viability of the material s , coating and primer. M aterial ability to resist adverse environmental conditions was negligible. These results are of particular interest for t he vehicles which are exposed in uncontrolled environment. Exposure of the primer an d coating to prohesion test showed, that the primer was able to resist failures during the entire test duration . However breakdown of th e coating was observed during the te st . Wear analyses of the o riginal piston which was designed before/during the 2 nd World War showed enhanced material composition and tribological pro perties than the new replacement piston . F ailures in the replacement piston and cylinder - liner could be att ributed to inadequate material selection and design. A sustainable model to extend longevity and to retard structural aging of the military tanks in The Tank Museum has been proposed.