#microstructures

Diskette Park - Microstructures EP

This Friday 3/20/26 on Underwater Computing.

Metals become stronger and more ductile with a millisecond electric pulse

A research team has developed a novel method that dramatically enhances the strength and toughness of titanium alloys using an electric current applied for only a few milliseconds. The team was led by Assistant Professor Shaojie Gu from the Magnesium Research Center, Kumamoto University, and included multi-institutional colleagues. In this study, a high-density pulsed electric current (HDPEC) treatment was applied to dual-phase titanium alloys, instantaneously inducing non-equilibrium atomic diffusion and phase transformations, thereby achieving microstructural refinement and multiphase formation. As a result, the toughness of the material was improved by up to 30%. Unlike conventional heat treatments, this method uniquely exploits the electron wind force (a non-thermal effect), in which electrons flowing through the material directly drive atomic motion. Through this mechanism, overall energy consumption was reduced by more than 50%.

Diskette Park - Microstructures EP

This Friday 3/20/26 on Underwater Computing.

Joris Laarman Lab | Microstructures (Aluminum Gradient Chair) | 2014

Nano 3D metallic parts turn out to be surprisingly strong despite defects

Scientists at Caltech have figured out how to precisely engineer tiny three-dimensional (3D) metallic pieces with nanoscale dimensions. The process can work with any metal or metal alloy and yields components of surprising strength despite having a porous and defect-ridden microstructure, making it potentially useful in a wide range of applications, including medical devices, computer chips, and equipment needed for space missions. The scientists describe their method in a paper published in the journal Nature Communications. The work was completed in the lab of Julia R. Greer, the Ruben F. and Donna Mettler Professor of Materials Science, Mechanics and Medical Engineering at Caltech, and Huajian Gao of Tsinghua University in Beijing.

Machining surface defect - AISI 1215 steel - Machining defects

Defect name: Surface defect Record No.: 690 Type of defect (Internal/Surface): Surface Defect classification: Machining defects Steel name:  Steel composition in weight %: 0.06% C, 0.96% Mn, 0.02% Si, 0.05% P, 0.31% S, 0.03% Cr, 0.03% Ni, 0.01% Mo, 0.06% Cu. Note:  One cold drawn and machined part exhibiting a linear defect indication on the machined ID surface was submitted to our laboratory for a metallurgical failure analysis service investigation. Our metallurgy experts were requested to determine the source cause of the ID surface defect indication. The material identification is shown in the table below. Based upon the opinion of our failure analysis lab and the performed examinations, it is our opinion the ID surface of the part contained a faint, intermittent, tool mark that was induced during the machining operation. No evidence was observed of a pre-existing internal steel defect or inclusion stringer on the ID surface that could have caused the defect indication. The microstructure as determined by the metal test lab was typical of AISI 1215 steel. SEM examination of the ID surface revealed a faint, intermittent, linear surface defect indication along the .234” diameter ID surface. (See arrows in Figures 1 - 2). Examination at higher magnification showed evidence of disturbed metal, most likely from the machining tool (see Figures 3 – 4). No evidence was observed of a pre-existing internal steel defect or inclusion stringer on the ID surface. Metallographic examination 1. A transverse section removed from the region containing the ID surface defect indication confirmed the presence of a tool mark that was induced during the machining operation. (See arrow in Figures 5 - 6). 2. No evidence was observed of an abnormal inclusion content or any other detrimental internal conditions that could have caused the defect indication. 3. The microstructure consisted of pearlite and grain boundary cementite in a matrix of ferrite, typical of AISI 1215 steel.

A beautiful blue butterfly wing offers a new way to study cancer

Shining polarized light through it and onto tissue can reveal how advanced the disease is

The morpho butterfly is a flying marvel. It flits through the rainforests of Central and South America. With wings that can span 20 centimeters (8 inches), it can be bigger than most human hands. Those wings shimmer with a dazzling blue hue. New data show these butterfly wings could one day become the basis of a new medical tool — one that might help doctors investigate the development and severity of some cancers. Although this butterfly’s wings are blue, that hue is not due to any pigment. Instead, it comes from how light reflects and refracts off tiny microstructures atop those wings. The shimmering color of the wing depends on how light hits it. (Many materials, from rocks to plastic wrap, have this property, called structural color.)

Taming heat: Novel solution enables unprecedented control of heat conduction

Prof. Gal Shmuel of the Faculty of Mechanical Engineering at the Technion—Israel Institute of Technology has developed an innovative approach that enables precise control of heat conduction in ways that do not occur naturally. The breakthrough could lead to new applications in energy harvesting and in protecting heat-sensitive devices. The research, conducted in collaboration with Prof. John R. Willis of the University of Cambridge, was published in Physical Review Letters. The researchers' approach is based on designing materials with asymmetric and nonuniform microstructures, inspired by similar methods previously developed for controlling light and sound—but never applied before to heat conduction. The challenge in adapting these ideas stems from the fact that light and sound propagate as waves, while heat spreads through a spontaneous process known as diffusion.