Corrosion resistance consolidation of a diaphragm type vacuum sensor
This paper describes the corrosion resistance consolidation of a diaphragm type vacuum sensor using a high corrosion resistance material. Initially, we had fabricated a vacuum sensor using a Ru based thin film amorphous alloy, whose high corrosion resistance was confirmed in wet tests. In the high corrosion gas tests, however, the sensor resists NF<inf>3</inf> and COF<inf>2</inf> gases but does not resist ClF<inf>3</inf> gas. Therefore, we searched for new Ni based amorphous alloys which can also resist ClF<inf>3</inf> using a combinatorial search based on a MEMS process. We were able to fabricate new sensors using Ni<inf>56</inf>Nb<inf>33</inf>Ti<inf>11</inf> and Ni<inf>49</inf>Nb<inf>35</inf>Ti<inf>16</inf> amorphous alloys which were shown to resist all three mentioned gases.
Microforming of three-dimensional microstructures from thin-film metallic glass
Thin-film metallic glasses (TFMGs) are characterized by an absence of size effect, high strength and high elastic limit due to their amorphous nature. As such, these materials are considered to be ideal candidates for microelectromechanical systems (MEMS). Furthermore, the TFMGs soften and show viscous flow within a certain temperature range called the supercooled liquid region (SCLR), which allows the TFMGs to be easily formed into three-dimensional (3-D) microstructures. The viscous flow in the SCLR is also useful for annealing and relaxing inner residual stresses of TFMGs. In the present paper, TFMG microcantilevers are fabricated by surface micromachining techniques. In order to heat and form the cantilevers, a local laser heating and microforming system is introduced, and the conditions of laser power and heating time that can not only form the cantilevers but also can maintain the amorphous nature of the TFMG are examined. Finally, based on the results of these investigations, microcantilevers having a 90/spl deg/ bend and a 90/spl deg/ twist, respectively, are successfully fabricated.
Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 ? 1 Rib Cotton Knitted Fabrics
This study investigates the impact of yarn count and stitch length of 100% cotton knitted fabrics. 1 × 1 ribs structured fabrics were used in this research work. The stitch length 2.50 mm, 2.52 mm, 2.60 mm, 2.70 mm, 2.80 mm and 2.96 mm were used of the yarn count of 26Ne, 28Ne and 36Ne. The areal densities of the grey fabrics were in various amounts. The impacts of yarn count and stitch length were measured concerning pilling resistance, abrasion resistance, and shrinkage and tightness factor. The result showed that the fabric pilling grade decreased while number of cycle increased. Abrasion resistance decreased but length wise shrinkage increased despite the fact that the stitch length increased. The results also exposed that the tightness factor of the fabric increased with the increase of the stitch length in both dyeing and washing state and finished state compared to grey state for the yarn count 26Ne and homogeneous result not found for yarn count 28Ne and 36 Ne. Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 × 1 Rib Cotton Knitted Fabrics