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.
Searching for Novel Ru-Based Thin Film Metallic Glass by Combinatorial Arc Plasma Deposition
We found out a novel Ru–Zr–Al thin film metallic glass by combinatorial arc plasma deposition (CAPD). To search for Ru-based thin film metallic glasses, first, a library of 1,089 CAPD samples was deposited, of which fifteen amorphous samples were selected by X-ray diffractometry. The compositions of these samples were measured by energy dispersive X-ray fluorescence spectrometry. From the fifteen samples, two samples having low Al content (Ru65Zr30Al5 and Ru67Zr25Al8, at. %) were chosen, and their compositions were reproduced in samples deposited by sputtering, because the CAPD samples were too small for evaluating the glass transition temperature Tg and crystallization temperature Tx by differential scanning calorimetry (DSC). DSC revealed that the two sputter-deposited samples Ru65Zr30Al5 and Ru67Zr25Al8 had a supercooled liquid region (SCLR), showing a Tg, Tx, and width of SCLR ΔTx (=Tx-Tg) of 902, 973, and 71 K in the case of Ru65Zr30Al5, and 913, 979, and 66 K in the case of Ru67Zr25Al8, respectively. Moreover, the sputter-deposited samples Ru65Zr30Al5 and Ru67Zr25Al8 exhibited superior mechanical properties. The fracture stress σf, elastic limit εl, and Young's modulus E were 1.9 GPa, 2.0% and 92.7 GPa, respectively, for Ru65Zr30Al5 and 1.9 GPa, 2.0%, and 91.6 GPa, respectively, for Ru67Zr25Al8.
ROOM- AND HIGH-TEMPERATURE MAGNETIC PROPERTIES OF Sm(CobalFexCu0.088Zr0.025)7.5 (x=0.30) SINTERED MAGNETS
The effect of Fe content on room- and high-temperature magnetic properties of Sm(CobalFexCu0.088Zr0.025)7.5 (x=0-0.30) sintered magnets, prepared by the conventional powder metallurgy method, has been systematically studied. With increasing Fe content, the remanences BT and maximum energy products (BH)max at room temperature gradually increase and reach optimal values of 1.055 T with x=0.27 for BT, and 205 kJ/m3 with x=0.21 for (BH)max, respectively, and then drop sharply with further Fe increase. An excessive addition of Fe (x≥0.24) results in rapid deterioration of permanent magnetic properties due to the formation of a considerable amount of FeCo soft magnetic phase. It was found that the effect of Fe content on high temperature stability is huge. The lower the Fe content, the smaller the temperature coefficient of coercivity. When x=0.07, a temperature coefficient of coercivity of -0.14%/K (293-723 K) can be achieved, as compared with -0.23%/K for x=0.21. BT of 0.725 T, bHc of 517 kA/m, iHc of 764 kA/m, and (BH)max of 95 kJ/m3 at 723 K were obtained, and the B-H demagnetization curve remains a straight line.