Adil Saeed

Material Characterization and Real-Time Wear Evaluation of Pistons and Cylinder Liners of the Tiger 131 Military Tank

Material characterization and wear evaluation of the original and replacement pistons and cylinder liners from a Tiger 131 are reported. The original piston and cylinder liner were operative in the Tiger engine during WWII. The replacement piston and cylinder liner were used as substitutes and were obtained after failure in 2 h of operation in the actual engine. Material characterization revealed that the original piston was aluminum silicon hypereutectic alloy approximately matching the specification of RSA-419 AE, with a silicon content of 19.92 wt%. The replacement piston was aluminum copper alloy with a low silicon content of 0.73 wt%, approximately satisfying specifications of Al 2031 and Al 2618-T6. Scuffing, material removal, and ploughing were observed in the replacement piston and cylinder liner. These failures were attributed to inadequate piston material and design. The replacement piston average surface roughness was 9.09 μm and for the replacement cylinder liner it was 5.78 μm. Characterization results showed that both the original and replacement cylinder liners consisted of mostly iron, which is indicative of cast iron, a common material for this application.

Corrosion Damage Analysis and Material Characterization of Sherman and Centaur—The Historic Military Tanks

A study of corrosion damage and material characterization of two historic military tanks, the Sherman and Centaur is reported. Experiments were conducted to analyse surface corrosion and corrosion propagation from surface to sub-surface. Significant surface corrosion was found, and this phenomenon was further facilitated by delamination failure mechanisms. Corrosion depth for the Sherman was approximately 110 μm, where sulphide inclusions were detected in the sub-surface analysis. The Centaurs analysis showed corrosion pits at 100 μm depth. These pits possess random geometrical configurations with evidence of sulphur, sodium, and calcium.

Modeling the Effect of Residual and Diffusion-Induced Stresses on Corrosion at the Interface of Coating and Substrate

The effect of residual and diffusion-induced stresses on corrosion at the interface of coating and substrate has been analyzed within a multidisciplinary approach, i.e., material science, solid mec...

Material characterisation to understand various modes of corrosion failures in large military vehicles of historical importance

Large military vehicles within museum collections are stored in two distinct environments, controlled and uncontrolled, with an intermittent transitional mode where vehicles travel between the two. Variable environmental conditions combined with operational factors pose significant risks to the reliability, durability and longevity of these vehicles. Although there are methods for retarding or decelerating aspects of failure, to maintain the integrity and originality of these vehicles as artefacts a sustainable methodology for conserving these vehicles should be developed. Corrosion is one of the significant contributors to the structural damage and material aging of historical military vehicles; therefore an experimental study was conducted to understand the prevailing mechanisms of failures due to corrosion with various types occurring in these vehicles identified. This paper presents various modes of corrosion in historic vehicles while X-ray Fluorescence and ultrasonic scanning corrosion mapping techniques characterise corrosion inhibiting materials and subsequent material loss. Understanding material profiles and their link to environmental exposure during use and non use of these vehicles will lead to a sustainable methodology for their conservation.

Accelerated corrosion tests of waste-gated turbocharger's adjustable and fixed end links

A turbocharger which has been mounted to a heavy duty automotive diesel engine can be subjected to various aggressive environments and a range of temperatures varying from ambient to 670°C. Extreme operating environments and temperatures can initiate corrosion leading to the degradation of the components. The present research evaluates corrosion resistance of the Zinc coated and Stainless Steel waste-gate end-links based on accelerated corrosion and dust particles test, using an Environmental Test Rig. Samples were exposed to the tests for 504 hours. Images of the specimens were captured to record corrosion build-up and its progression on the surfaces during the exposure time. These results were then used to evaluate the corrosion resistance ability of both, Zinc coated Fixed and Stainless Steel Adjustable End-Links. Accumulation of corrosion and the build-up of salt deposits were observed on both End-Links during/after the experiments.

Analyzing and Modelling the Corrosion Behavior of Ni/Al2O3, Ni/SiC, Ni/ZrO2 and Ni/Graphene Nanocomposite Coatings

A study has been presented on the effects of intrinsic mechanical parameters, such as surface stress, surface elastic modulus, surface porosity, permeability and grain size on the corrosion failure of nanocomposite coatings. A set of mechano-electrochemical equations was developed by combining the popular Butler–Volmer and Duhem expressions to analyze the direct influence of mechanical parameters on the electrochemical reactions in nanocomposite coatings. Nanocomposite coatings of Ni with Al2O3, SiC, ZrO2 and Graphene nanoparticles were studied as examples. The predictions showed that the corrosion rate of the nanocoatings increased with increasing grain size due to increase in surface stress, surface porosity and permeability of nanocoatings. A detailed experimental study was performed in which the nanocomposite coatings were subjected to an accelerated corrosion testing. The experimental results helped to develop and validate the equations by qualitative comparison between the experimental and predicted results showing good agreement between the two.

RESEARCH IMPACT OF CONSERVING LARGE MILITARY VEHICLES THROUGH A SUSTAINABLE METHODOLOGY

The objective of this article is to present the research impact, significance and reach made for British military heritage. An effective knowledge exchange model is being developed in terms of substantial contribution to the identification, measurement, analysis, prediction and condition-monitoring of structural failures within military tanks with enormous societal and economic impact. This is the first evidence-based research carried out in this field and is directly linked to the development of a new conservation facility, further research and grants.

A Novel Non-Destructive Sensing Technology for On-Site Field Electrochemical Impedance Testing of Coatings

The quality of coating and the resulting rate of corrosion of the underlying metal substrate can be measured by a variety of corrosion measurements (Tafel, electrochemical impedance spectroscopy) by using standard laboratory electrochemical cells. However, there is always a need of low cost, portable, and non-destructive electrochemical cells, which can be used on-site field for condition monitoring of large structures for example bridges and large infrastructures, complex operating systems as aircrafts, precision machines, petrochemical processes, automotive, and locomotives. This research has developed state of the art cells fabricated by using a special magnetic aluminum compound (AlnXn), which is highly electrically conductive and corrosion resistive. The research has commissioned for deploying this novel sensing technology for micro-defects detection, corrosion rate measurement, and condition assessment of the defected coatings. Tafel measurement facilitated by these non-destructive cells is used to detect micro-defects and corrosion rate measurement while electrochemical impedance spectroscopy measurement is facilitated to measure the coating condition. This technology has been successfully tested and commissioned on automotive, hazardous compartments with polymeric coatings and bridges to assess their coating condition in terms of their structural integrity. Post design testing involved the installation of these cells, running diagnostics, data acquisition, and macrographs to predict structural defects and the resulting corrosion rate. This technology enables the design process to incorporate operational conditions and fully realize more durable and reliable solutions to be applied to high-value large structures and complex interacting systems. Current developments in corrosion condition monitoring especially cost effective and non-destructive techniques to assess structural integrity beneath nonconductive and polymeric coating were long awaited. This reported development will revolutionize durability and reliability assessment techniques to enhance safety and mitigate catastrophic failures for cost savings and avoiding fatal accidents.