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In the present investigation, the 304 austenitic stainless steel has been strained up to 0% and 15% reduction in thickness, and analysis has been done with the help of X-ray diffraction (XRD) and microstructure. In 304 austenitic stainless steel (ASS) the microstructure through optical as well as scanning electron microscope 9SEM) has been studied at various thermal aging temperatures with and without strained at 0% and 15%. X-Ray diffraction results show that as stacking fault energy is greater with an increase in straining from 0% to 15%, 304 ASS seems to be deformed more quickly, resulting in a fast conversion to strain induced martensite from austenite. The XRD data also show that a higher percentage of martensite was produced. Microstructure results indicated that due to straining and high temperature heat treatment of 950°C-1000°C, small refined grains of new austenite formed which became the main reason for high strength and ductility. However other side shows that at a common temperature of 850°C-900°C, according to a microstructural study, the martensitic areas are an ideal source for increasing sensitization. [ABSTRACT FROM AUTHOR]

This study is focused on the utilization of the limestone from Aceh province, Indonesia, as a raw material for preparing inorganic oxide using a high thermal decomposition method. In this preliminary experiment, the limestone material was powdered, then calcined at a temperature of 900 °C for 4 hours under atmospheric pressure and modified with several concentrations of nickel element (1, 3, 5 wt%). The prepared catalyst was characterized using analytical instruments, namely X-Ray Diffraction (XRD) and Scanning Electron Microscope Energy Dispersive Spectroscopy (SEM-EDS). Based on the diffractogram of XRD, it can be known that the prepared catalyst was dominated by CaO crystals, in which Al2O3 was a minor compound. Characterization of the prepared catalyst using SEM-EDS demonstrated that the catalyst has a homogeneous morphology and uniform particle size. [ABSTRACT FROM AUTHOR]

The composite strength depends on the effectivity of interface interaction between the fiber and the matrix. The chemical treatment makes fiber surfaces more compatible with a hydrophobic polymer. So, this study aims to determine the influence of silane coupling agent concentration on the interfacial shear strength in the fiber composite of the Sansevieria cylindrica fiber. The methods included fibers treatment using ethanol as a dissolving and silane coupling agent with concentrations of 2.5%, 5%, 7.5%, and 10%. Fibers were embedded into the epoxy polymer for as long as 200 µm. The interfacial shear strength test was conducted through a single fiber pull-out test. Fiber morphology, crystallinity, and the functional group were observed using a scanning electron microscope and X-ray diffraction (XRD), respectively. As a result, the morphology of S. cylindrica fibers became rougher and showed a rougher surface after a silane concentration of 7.5%, but with the proper concentration, some fiber surfaces provided a good interface. Analysis using X-ray diffraction (XRD) on S. cylindrica fibers without treatment showed a crystalline index of 66%. Increasing silane concentration by 10% and the crystalline index by 75%. The treatment with a silane concentration of 0.0%, 2.5%, 5.0%, 7.5%, and 10.0% results in interfacial shear strength of 39.936, 59.300, 76.742, 83.965, and 91.321 MPa, respectively. The interfacial shear strength increases when the concentration of silane coupling agent increases, with the highest shear strength of 91.321 MPa at a silane concentration of 10%. The silane coupling agent changes hydroxyl groups into silanol groups in fibers, making a bond between the matrix and fibers. It can conclude that the treatment of a silane coupling agent increases the interfacial shear strength of the interface of S. cylindrica fiber-epoxy composite. [ABSTRACT FROM AUTHOR]