Pulsed laser deposition (PLD) is a good method for growing high-quality functional oxide thin films because of the technical simplicity and the ease with which deposition can be switched from one material to another. However, the repeatability of film quality is often hard to achieve, especially when using several different PLD systems. Here we report the steps that we have taken to grow nearly bulk-equivalent defect-free thin films, with SrTiO3 as an example, by using PLD in a reproducible fashion. The ablation laser fluence was found to have a very strong effect on the lattice constant and defect structure of the films. Nonstoichiometric transfer of material from the ablation target was observed when either the laser fluence or the beam spot area was inadequate.

The main purpose of using combinatorial techniques for materials science studies is to achieve higher experimental throughput than what is possible when samples are synthesized and characterized one at a time. The instrumentation needed for performing high-throughput synthesis and characterization has seen rapid development in recent years. The software tools needed to connect all parts of the materials development process are still largely lacking. In this paper we discuss the requirements of a combinatorial informatics system for materials science experiments. Specifically, we focus on solid-state thin film synthesis. We also describe an implementation of such a system that is based on widely-available open-source software. The system offers features such as remote access via a Web browser, an electronic notebook-style Web interface, automatic upload of new measurement or processing results and rapid preview of experimental data.

In order to improve fatigue strength in welded joints, low transformation-temperature welding wire has been developed in which residual tensile stress can be reduced. In application of the low transformation-temperature welding wire, the prevention of cold cracking without preheating in high strength steel welded joints is expected and examined from the control of residual tensile stress. However, it is expected that residual stress distribution in welded joint can be suggested by numerical analysis, because the residual stress cannot be measured simply and non-distractively. In this report, martensite transformation behavior such as Ms point, transformation expansion and so on is measured firstly by Formaster test. And temperature dependence of several mechanical properties was measured in full-austenite and full martensite microstructures, and temperature dependence of mechanical properties was estimated in dual phase microstructure of austenite and martensite. By these data, numerical analysis was carried out and martensite transformation behavior was compared with measured and calculated results in side rigid model test. From the comparison, it was suggested that transformation superplasticity had to be considered in numerical analysis. Next, the increase of Ms point due to transformation induced plasticity was guessed from the comparison with measured data by laser speckle measurement and calculated data under transformation superplasticity consideration. From the all results, it was found that the measured transformation behavior and residual stress had the good agreement with the calculated results under transformation superplasticity and transformation induced plasticity considerations.

No abstract