Advanced Materials Research Vols. 299-300

Abstract: Copper based composite powders with nano-SiO₂ were prepared by mechanical milling technology. The effects of milling time on morphology and component of the composite particles were characterized by scanning electron microscopy (SEM) and energy disperse X-ray spectroscopy (EDS), respectively. Results showed that dendrite composite particles change to the flaky, and then to spherical ones with the milling time increasing. The n-SiO₂ particles disperse more homogeneously in the composite particles with the milling time increasing.

Abstract: According to the test specifications of Bench test methods of automotive telescopic shock absorber（QC/T545-1999）, through controlling variable frequency motor which drives crank-link-slider mechanism，harmonic excitation is acted on shock absorbers. Meanwhile, signals of two force sensors and displacement sensor are acquired. The synchronous performance test of single condition and multi-work condition is achieved for shock absorbers in automotive coaxial suspension. The velocity characteristic and resistance-displacement characteristic are tested in specified range of the velocity of motor.

Abstract: Elemental identification of material is a prime most important in material science field. Electric discharge is used for material elemental identification with optical emission spectroscopy. During electric discharge machining between two electrodes plasma is generated which emits intense radiation in the UV-Visible region. The generated plasma captured by optical emission spectroscopic technique and elements are identified from recorded spectra by matching with standard NIST database. This method is simple, rapid, and inexpensive compared to all other elemental identification method. The elements of the metal, semiconductors, even insulators can be identified without much difficulty. The elemental identification of material has been investigated in macro and micro level.

Abstract: To improve the performance of the Electric discharge machining (EDM) process it is of interest to characterize the plasma involved. Plasma temperature needs to be measured as an initial phase of plasma characterization. Non-contact optical emission spectroscopy has been used to measure the plasma temperature. The plasma temperature and crater morphology has been investigated for different energy conditions on Silicon in dry µ-EDM condition. The plasma temperature is calculated using line pair method and crater morphology analyzed by scanning electron microscope (SEM) and profilometer.