Engineering Conferences International
Not a member yet
9271 research outputs found
Sort by
Simulated control strategy for product diversion management during continuous processing
Get PDFPlease click Additional Files below to see the full abstract
Solid polyethylene glycol precipitation: Potential cost reduction in antibody downstream processing
Get PDFPlease click Additional Files below to see the full abstract
Effect of hydrogen on the nanomechanical behavior of dual-phase nanocrystalline high-entropy alloy
Get PDFPlease click Additional Files below to see the full abstract
Nano mechanical and microstructural investigation of damage mechanisms in copper wire bonds
Get PDFPlease click Additional Files below to see the full abstract
A new method to measure shear surface mechanical properties
Get PDFPlease click Additional Files below to see the full abstract
From microlattices to 3d microprinting of multiphase micro-components: Resolution limits and mechanical properties under extreme conditions
Get PDFTwo-photon lithography (TPL) enables the fabrication of metamaterials such as polymer micro-lattices. They are designed to achieve their envisioned mechanical properties through stretching and bending of individual trusses. Several novel approaches are developed here to a) directly print metal microlattices, b) fabricate multiphase composite microlattices and c) shrink the truss diameter below the diffraction limit of light, all with the ultimate goal to enable fabrication of a full dense material with microprinted 3D architecture of different phases. Copper microlattices and micropillars with truss diameters in the few micron range were printed directly via fluid AFM based local electroplating [1]. It was identified that microcrystalline copper micropillars deform in a singleshear like manner exhibiting a weak strain rate dependence at all strain rates. Ultrafine grained (UFG) copper micropillars, however, deform homogenously via barreling and show strong rate-dependence and small activation volumes at strain rates up to ∼ 0.1 s−1, suggesting dislocation nucleation as the deformation mechanism. At higher strain rates, yield stress saturates remarkably, resulting in a decrease of strain rate sensitivity implying a transition in deformation mechanism to collective dislocation nucleation. Finally, the copper microlattices are shown to increase in strength if conformally coated with Nickel with thicknesses in the several 100nm range.
Please click Download on the upper right corner to see the full abstract
Fracture properties of CrN hard coatings: Influence of the microstructure, alloying elements, and coating architecture
Get PDFTransition metal nitrides are well known and applied as protective coating materials based on their unique refractory characteristics, such as high hardness or Young’s modulus. However, for long-term applications, the fracture toughness KIC is an essential factor as the integrity of the coating-substrate interface is impaired by cracking and subsequent environmental attacks.
Please click Download on the upper right corner to see the full abstract
Micro-scale damage tolerance studies in ferroelectric barium titanate thin films
Get PDFBarium Titanate (BTO) is a brittle, lead free ferroelectric and piezoelectric ceramic used in the miniature form in microscale electrical device applications as capacitors, actuators and sensors. During service this material system develops mechanical stresses due to thermal and electric loads acting on the system, which leads to the failure of the system due to cracking in the films or interface delamination. Micropillar compression revealed a size effect in strength with a size exponent close to 1 and an enhancement in elastic strain limit [1]. It also revealed strain accommodation by dislocation plasticity. However, signature of plastic deformation in compression (Figure 1a) does not necessarily translate to crack tip plasticity tension for brittle ceramics.
Please click Download on the upper right corner to see the full abstract
Progress in the development of high strain rate nanoindentation testing
Get PDFOver the past three years, we have developed new hardware, software and testing methods to conduct nanoindentation testing at the very high strain rates. To date, indentation strain rates as high as 104/s have been achieved during the initial stages of indentation contact with a Berkovich indenter, with the potential to go even higher. At the heart of the new testing system is a laser interferometer that measures indenter displacements with sub-nanometer resolution at data acquisition rates in excess of 1 MHz. High data rates are essential since the loading of the indenter usually lasts no longer than a few hundred microseconds. The new testing system also incorporates a very high stiffness hexapod for precise sample positioning and alignment, and various hardware modifications that provide for the measurement of indentation load at speeds commensurate with the displacement measurements. Various testing methods have been explored, including impact tests in which the indenter is accelerated to velocities up to 0.3 m/s before contacting the specimen, and step load tests in which the indenter starts in contact with the specimen and is then step loaded to a high value in a relatively short period of time. Results demonstrating the capabilities and limitations of the system are presented and discussed based on experiments conducted in fused silica, as a model hard material, and aluminum, as a model soft material. New methods for analyzing the nanoindentation data to extract hardness as a function of strain rate are presented