Investigation on Foamed PP/Nano-CaCO3 Composites in a Combined in-Mold Decoration and Microcellular Injection Molding Process

A combined in-mold decoration and microcellular injection molding (IMD/MIM) method has been used in this paper. The foamed PP/nano-CaCO3 composites were prepared to investigate their mechanical properties, cellular structure, and surface quality. The content of nano-CaCO3 varied from 0 to 10 wt %. The results showed that nano-CaCO3 acted as a reinforcing phase and nucleating agent, which help to improve the mechanical properties of foamed composites. The cellular structure and mechanical properties were optimum when the nano-CaCO3 content was 6 wt %. In the vertical section, the cell size and density of transition layer on the film side was bigger than that on the non-film side. In the parallel section, the cell ratio of length to diameter of transition layer on the film side was smaller than that on the non-film side, and the cell tile angle was larger than that on the non-film side. With nano-CaCO3 content increasing, the surface quality showed a trend of decreasing first and then increasing.

A Combined In-Mold Decoration and Microcellular Injection Molding Method for Preparing Foamed Products with Improved Surface Appearance

A combined in-mold decoration and microcellular injection molding (IMD/MIM) method by integrating in-mold decoration injection molding (IMD) with microcellular injection molding (MIM) was proposed in this paper. To verify the effectiveness of the IMD/MIM method, comparisons of in-mold decoration injection molding (IMD), conventional injection molding (CIM), IMD/MIM and microcellular injection molding (MIM) simulations and experiments were performed. The results show that compared with MIM, the film flattens the bubbles that have not been cooled and turned to the surface, thus improving the surface quality of the parts. The existence of the film results in an asymmetrical temperature distribution along the thickness of the sample, and the higher temperature on the film side leads the cell to move toward it, thus obtaining a cell-offset part. However, the mechanical properties of the IMD/MIM splines are degraded due to the presence of cells, while specific mechanical properties similar to their solid counterparts are maintained. Besides, the existence of the film reduces the heat transfer coefficient of the film side so that the sides of the part are cooled asymmetrically, causing warpage.

C-Axis Oriented ZnO Film by RF Sputtering and its Integration with MEMS Processing

In the present work, we report a new fabrication process to integrate the “c-axis oriented” ZnO films with bulk-micromachined silicon diaphragms. ZnO films are very sensitive to the chemicals used in the micro-electro-mechanical systems (MEMS) fabrication process which include acids, bases and etchants of different material layers (e.g. SiO2, chromium, gold etc.). A Si3N4 layer is incorporated to protect the ZnO film from the etchants of chromium and gold used for patterning the electrodes. A mechanical jig is used for protecting the front side (ZnO film side) of the wafer from ethylenediamine pyrocatechol water (EPW) during the anisotropic etching of silicon. The resistivity measurement performed on the ZnO film integrated with micro-diaphragm shows the reliability of the fabrication process proposed in this work.

Characterization of Tungsten Silicides Formed by Rapid Thermal Annealing.

ABSTRACTTungsten silicide samples were formed by sputter depositing 80 nm W metal onto (100) oriented, 5 ohm-cm Si wafers. After deposition, the samples were fast radiatively processed in an RTA system using quartz-halogen tungsten lamps as radiation sources for time intervals ranging from 20 to 60s under high vacuum. Films processed at 22–25 W/cm2 radiation with the film side of the samples oriented away from the lamps result in films which are metallic or cloudy in color, and have mixed composition as evidenced by x-ray diffraction (W, W5 Si3 and WSi2). Films processed with the film side oriented toward the lamps show the occurrence of a phase transforF.ation clearly nucleated at the film edge. The new phase is grey and mostly composed of WSi2, with film resistivities 55–60 μΩ-cm. AES measurements show a uniformly distributed Si diffusion profile into the metal film, while SEM indicates a nucleation and growth of the phase once diffusion occurs.

Examination of Passive Films on Iron-Nickel Alloys by Auger Electron Spectroscopy

Detailed analysis of anodic films formed on amorphous iron-nickel alloys containing phosphorus, boron, and molybdenum has been performed by Auger electron spectroscopy. These films contain considerable quantities of P and B both of which are highest at the metal/film interface. Phosphorus accumulates on the metal side of the interface while boron accumulates on the film side, with continuous variation throughout the film thickness. In the film phase, phosphorus shows complex oxidation states. Molybdenum is also found in the films at low concentrations. Polarization curves show that these alloys exhibit greater passivity in 1M HCl than a comparable polycrystalline iron-nickel alloy.