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Total hip arthroplasty or total hip replacement (THR) is a surgical procedure for inserting an implant, which aims to restore the functionality of movements lost due to fractures, joint wear, bone loss and other problems. Although the THR procedure is consolidated in medicine, failures in THR implants associated with different problems are frequently reported in the literature. The aim of the present study was to identify and evaluate the reasons that led a THR implant to fail prematurely after 2 years of use in a 65-year-old female patient. In order to identify the reason of the failure, the following techniques were used: optical microscopy, scanning electron microscopy, chemical analysis by energy-dispersive spectroscopy, Vickers microhardness measurements, digital image processing technique and a mathematical method of finite element analysis. It was concluded that the fractured implant presented a fatigue mechanism, due to existence of pits on the surface.

In this paper, a European black Japanned piece of furniture (dated to approximately 1860) was analyzed by XRF, Raman spectroscopy and FT-IR techniques. The analyses detected pigments such as vermilion/cinnabar [HgS], Massicot [PbO], lamp black [C] and green earth [K[(Al,FeIII),(FeII,Mg)](AlSi3,Si4)O10(OH)2], which were possibly dissolved in gum arabic. The analyses also determined that the metallic ornaments consist of a brass alloy with traces of gold and that gold was also used in some golden regions of the polychrome. The results obtained assisted restorers in choosing suitable intervening procedures and contributed to a better understanding of the cupboard manufacturing process.

This work aimed to identify and evaluate the reasons that led to a compression spring to fail. The compression spring was operating in a wagon torpedo, a vehicle that transported pig iron in a liquid state from the blast furnace to the steel mill. For this purpose, optical microscopy (OM), scanning electron microscopy (SEM), quantitative chemical analysis by combustion and x-ray fluorescence, Vickers microhardness test (HV), Rockwell superficial hardness with N scale (HRN), and residual stress analysis by x-ray diffraction were used. The industrial quenching, tempering heat treatment, and shot peening process, were also redone for the spring under analysis, all in order to simulate the treatments that were supposedly done on the original spring. It can be concluded that the process that led to spring fracture was a mechanism of fatigue failure that originated from a defect in the spring surface. Although residual stresses on the spring surface were expected to prevent fatigue failures from surface defects, the hardness in this region of the material was lower than specified due to a decarburizing process.

This work aimed to analyze a failure that occurred prematurely in an ASTM SS Grade 70 steel tube in the cooling system of a reheating furnace. The following techniques were used: visual inspection, optical microscopy (OM), scanning electron microscopy (SEM), chemical analysis by energy dispersive spectroscopy (EDS), Vickers microhardness (HV) and measurements and chemical analysis by optical emission spectrometry (OES). It was concluded that the failure was caused by a drastic corrosion process, due to microstructural changes resulting from the loss of the refractory coating.

The superduplex stainless steels (SDSS) are widely used in chemical, oil and gas industries, to pipelines and storage material facilities. In welding process or working in temperature elevated, secondary phases may appear in the form of precipitates, as the sigma phase (σ) which is an intermetallic compound. This compound is harmful to the properties of steel, deteriorating its mechanical properties, such as decreasing corrosion resistance and toughness. In this paper it is analyzed the formation, kinetics and microstructural evolution of sigma phase in SDSS UNS S32750 after isothermal aging at 700ºC, 750ºC and 800ºC. In this work sigma phase kinetics is studied by JMAK theory and by two microstructural path descriptors, SV, interfacial area per unit of volume between sigma phase and austenite, and , mean chord length of sigma, both in function of the VV, volumetric fraction of sigma, known in the literature as microstructural partial path (MP). The MP formulation is common in recrystallization studies, but so far has not been used in the sigma phase precipitation studies, being applied here for the first time. The results indicated that the sigma phase nucleates by site saturation with anisotropic linear impingement. This means that sigma phase nucleates on edges.