Nanograin metals and metallic multilayers produced by severe plastic deformation

This research has developed an improved understanding of the structure-property relationships, fabrication technology and deformation mechanism of light bulk ultrafine grained materials and metallic multilayered structure.

Characterization of microstructures and tensile properties of TRIP-aided steels with different matrix microstructure

Three different heat treatment processes have been proposed as a fundamental method to produce three kinds of TRIP-aided steels with polygonal ferritic matrix (F-TRIP), bainitic matrix (B-TRIP) and martensitic matrix (M-TRIP) in a newly designed low alloy carbon steel. By means of dilatometry study and detailed characterization, the relationships among transformation, microstructure and the resulting mechanical behavior were compared and analyzed for the three cases. The work hardening of the samples was evaluated by calculating the instantaneous n value as a function of strain. The M-TRIP sample exhibits the highest strength with the highest work hardening rate at low strains and subsequent rapid descending at high strains. In contrast, the B-TRIP sample has relatively high continuously constant work hardening behavior over strain levels greater than 0.067. The difference in work hardening behavior corresponds directly to the rate of the retained austenite-martensitic transformation during straining, which can be attributed to the carbon content, the morphology of the retained austenite and the matrix microstructure in the respective TRIP-aided samples. © 2014 Elsevier B.V.

Malnutrition: significance, prevalence and management of the hospitalised surgery patient

Malnutrition is prevalent and poorly diagnosed in hospitalised patients, with high rates of malnutrition seen in surgical patients. The administration of a specialised immuno-nutrition supplement is beneficial for malnourished patients undergoing gastrointestinal surgery, and a multidisciplinary team approach improves nutritional care for patients.

Effect of B4C, TiB2 and ZrSiO4 ceramic particles on mechanical properties of aluminium matrix composites: Experimental investigation and predictive modelling

This paper focuses on the influence of processing temperature and inclusion of micron-sized B4C, TiB2 and ZrSiO4 on the mechanical performance of aluminium matrix composites fabricated through stir casting. The ceramic/aluminium composite could withstand greater external loads, due to interfacial ceramic/aluminium bonding effect on the movement of grain and twin boundaries. Based on experimental results, the tensile strength and hardness of ceramic reinforced composite are significantly increased. The maximum improvement is achieved through adding ZrSiO4 and TiB2, which has led to 52% and 125% increase in tensile strength and hardness, respectively. To predict the effect of incorporating ceramic reinforcements on the mechanical properties of composites, experimental data of mechanical tests are used to create 3 models named Levenberg-Marquardt Algorithm (LMA) neural networks. The results show that the LMA- neural networks models have a high level of accuracy in the prediction of mechanical properties for ceramic reinforced-aluminium matrix composites.

Comparison of the properties of compacted and porous lamellar chitosan-xanthan membranes as dressings and scaffolds for the treatment of skin lesions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)