Synchrotron X-ray diffraction investigation of the surface condition of artefacts from King Henry VIII's warship the Mary Rose.

Synchrotron X-ray diffraction (XRD) measured on the XMaS beamline at the ESRF was used to characterize the alloy composition and crystalline surface corrosion of three copper alloy Tudor artefacts recovered from the undersea wreck of King Henry VIII's warship the Mary Rose. The XRD method adopted has a dynamic range ∼1:105 and allows reflections <0.002% of the height of major reflections in the pattern to be discerned above the background without smoothing. Laboratory XRD, scanning electron microscopy-energy dispersive spectroscopy, synchrotron X-ray fluorescence and X-ray excited optical luminescence-X-ray near-edge absorption structure were used as supporting techniques, and the combination revealed structural and compositional features of importance to both archaeology and conservation. The artefacts were brass links believed to be fragments of chainmail and were excavated from the seabed during 1981 and 1982. Their condition reflects very different treatment just after recovery, viz. complete cleaning and conservation, chemical corrosion inhibition and chloride removal only, and distilled water soaking only (to remove the chlorides). The brass composition has been determined for all three at least in the top 7 µm or so as Cu(73%)Zn(27%) from the lattice constant. Measurement of the peak widths showed significant differences in the crystallite size and microstrain between the three samples. All of the links are found to be almost chloride-free with the main corrosion products being spertiniite, sphalerite, zincite, covellite and chalcocite. The balance of corrosion products between the links reflects the conservation treatment applied to one and points to different corrosion environments for the other two.

SR-XRD in situ monitoring of copper-IUD corrosion in simulated uterine fluid using a portable spectroelectrochemical cell.

The objective of this work is to study the initial corrosion of copper in the presence of gold when placed in simulated uterine fluid in order to better understand the evolution of active components of copper-IUDs. In order to carry out this study, a portable cell was designed to partially simulate the uterine environment and provide a way of tracking the chemical changes occurring in the samples in situ within a controlled environment over a long period of time using synchrotron spectroelectrochemistry. The dynamically forming crystalline corrosion products are determined in situ for a range of copper-gold surface ratios over the course of a 10-day experiment in the cell. It is concluded that the insoluble deposits forming over this time are not the origin of the anticonception mechanism.

Evaluation of an X-ray-excited optical microscope for chemical imaging of metal and other surfaces.

The application of a modular system for the nondestructive chemical imaging of metal and other surfaces is described using heritage metals as an example. The custom-built X-ray-excited optical luminescence (XEOL) microscope, XEOM 1, images the chemical state and short-range atomic order of the top 200 nm of both amorphous and crystalline surfaces. A broad X-ray beam is used to illuminate large areas (up to 4 mm(2)) of the sample, and the resulting XEOL emission is collected simultaneously for each pixel by a charge-coupled device sensor to form an image. The input X-ray energy is incremented across a range typical for the X-ray absorption near-edge structure (XANES) and an image collected for each increment. The use of large-footprint beams combined with parallel detection allows the power density to be kept low and facilitates complete nondestructive XANES mapping on a reasonable time scale. In this study the microscope was evaluated by imaging copper surfaces with well-defined patterns of different corrosion products (cuprite Cu2O and nantokite CuCl). The images obtained show chemical contrast, and filtering the XEOL light allowed different corrosion products to be imaged separately. Absorption spectra extracted from software-selected regions of interest exhibit characteristic XANES fingerprints for the compounds present. Moreover, when the X-ray absorption edge positions were extracted from each spectrum, an oxidation state map of the sample could be compiled. The results show that this method allows one to obtain nondestructive and noninvasive information at the micrometer scale while using full-field imaging.

Assessment of copper corrosion from frameless copper IUDs after long-term in utero residence.

OBJECTIVE: To assess the site-specific corrosive behavior of the frameless intrauterine device (IUD) following long-term exposure to the uterine environment. STUDY DESIGN: A qualitative and morphological study using X-ray diffraction (XRD) and scanning electron microscopy (SEM). RESULTS: Three GyneFix® IUDs that were in site up to 150 months were examined. In utero corroded copper sleeves were divided into 10 different groups based on their shape (U or O), orientation (inside or outside) and in utero residence time. XRD indicated the presence of solely cuprite (Cu2O) as corrosion product on both the inside and the outside of the copper sleeves, regardless of their shape. These results were confirmed by backscattered electron micrographs recorded on the inside, the outside and the cross-section of the IUD sleeve. SEM results suggest that shape and orientation slightly affect the corrosion rate. CONCLUSION: The apparent copper loss from both sides of GyneFix copper tubes proves that both sides are a potential copper source and therefore justifies the design of GyneFix IUD. This could be beneficial for women as the IUD could be reduced in size and therefore better tolerated. The impact on bleeding could also be minimized. IMPLICATION STATEMENT: Release of copper ions from both sides of the copper tubes of the frameless GyneFix® IUD allows the IUD to be reduced in size, contributing to better toleration. The impact on menstrual bleeding is also minimized by a smaller size of the foreign body.