A Comprehensive Study On Soundness, Microstructure and Uniformity of 2024 Aluminum Cups Hydro-Mechanically Drawn at Elevated Temperatures

In the present research work, the hydro-mechanical deep drawing (HMDD) process of 2024 aluminum alloy is performed experimentally and numerically for elevated temperatures. The main variables of the forming process include the fluid pressure, the pre-bulge pressure and the process temperature. The effects of these parameters on the thickness distribution and uniformity index of the final product have been investigated. Using the hardness test, the preferred crystallographic orientation, the energy dispersive spectroscopy and microstructure images obtained from an optical microscope and a scanning electron microscope, the relationship between the grain size, hardness and the effective plastic strain are studied and discussed. The findings imply that the HMDD process without the pre-bulge pressure reduces the uniformity of the final product and, on the other hand, excessive increase in this parameter causes tearing of the workpiece. The hardness distribution along the cup wall was in agreement with grain refinement and the Hall-Petch relationship, but it was not correspond to the expectations made via the texture analyses. The images gained from the energy dispersive spectroscopy for different areas of the 2024 Al sample demonstrated that the Al2Cu precipitations in the product wall were finer than the other areas and mainly dispersed at the grain boundaries. This type of precipitation distribution was the main origin for increasing the hardness of the cup wall in comparison with the cup corner and bottom. In other words, the precipitation hardening overwhelmed the influence of the preferred orientation of the grains in HMDD operation of Al 2024.

Short Communication: Morphological study of the scales of Barbodes cf. binotatus (Cyprinidae) from Toba Lake, Indonesia by using Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS)

Lubis K, Sudibyo M, Siregar EH, Laili N. 2021. Short Communication: Morphological study of the scales of Barbodes cf. binotatus (Cyprinidae) from Toba Lake, Indonesia by using Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS). Biodiversitas 22: 3821-3828. Spotted barb (Barbodes cf binotatus) is a freshwater fish of Sumatra Island, especially found in the Toba. The study of morphological characteristics of the scales of Spotted barb (B. cf binotatus) is necessary in fish taxonomy. Therefore, the present study investigated the morphology and the chemical elements of the scales located between the dorsal fin and lateral line and those on the lateral line using SEM-EDS (Scanning Electron Microscope (SEM)- Energy Dispersive X-ray Spectroscopy (EDS). We found that the scales of Spotted barb (B. cf binotatus) have the general morphological characteristics of cycloid scales. The morphologies of the scales between the dorsal fin and lateral line and those on the lateral line are slightly different. Lateral line scales of Spotted barb (B. cf binotatus) have no focus area, replaced by a lateral line canal located along the anterior-posterior axis of the scales with two openings. The anterior opening is bigger and wider in compared to the posterior opening. The circuli of the dorsal fin scale is orientated towards the focus. However, the circuli of the lateral scale faces the lateral line canal. The scales contain some elements such as Ca, K, O, Mg, Na, and P.

A New Quantitative Approach for Element-Mineral Determination Based on “EDS (Energy Dispersive Spectroscopy) Method”

With the continuous development of hydrocarbon exploration, how to efficiently, economically, accurately, and comprehensively obtain mineral species, composition, and structure and diagenesis information has become one of the hot topics in both the academia and industry. By scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), a new method of qualitative mineral identification and quantitative measurement is established. Typical tight sandstone reservoir rock samples in the Ordos Basin are selected; through the element surface scanning image of “mineral element composition” and “pixel element combination”, mineral types are distinguished, and mineral parameters such as types, characteristics, and content are rapidly and accurately determined. Meanwhile, such results achieved via the new method are compared with conventional XRD and TIMA methods. The results show that the new method exhibits several advantages: cost advantages compared to XRD experiment analysis technology and TIMA system and ability to analyze low content minerals which XRD techniques are hard to identify; it allows quantitative characterization on the phenomenon of mineral miscibility, which is of great significance to explore the mineral diagenetic evolution.