| 摘要 |
<p>Coaxial sliding resistor prodn. process takes place by steps: (a) drying at 110-120 degrees C for 13-17 hrs. and mixing the following components: (i) 37-41 (pref. 39) wt. % carbonyl Fe powder A having grain-size 6-8 mu and specific vibration wt. 4.4-4.5 g/cm3, consisting of >=99.6% Fe admixed with =0.1% Ni, 0.03% Mo, 0.05 % C, 0.2 % O2 and 0.01 % N2, (ii) 34.2-37.8 (pref. 36) wt. % carbonyl Fe powder B having grain-size 2.3-2.5 mu and specific vibration wt. 4.3 g/cm3, consisting of >=98.3% Fe admixed with 0.1% Ni, 0.03% Mo, 0.6% C, 0.3 % O2 and 0.8% N2, (iii) 2-3 (pref. 2.5) wt.% ferrite flux, consisting of 15% ZnO, 14.8 % MnO, 12.4 % FeO and 57.7 % Fe2O3 and (iv) 0.4-u wt.% filler, pref. 0.5 wt.% quartz dust; (b) further mixing with 21-23 (22) wt.% binder consisting of liquid epoxy resin and hardener in ratio 100:25; (c) evacuating at press. 1 Torr for 15 min.; (d) casting in a mould; (e) hardening at 20-25 degrees C in 15 hrs.; (f) re-hardening to =70 degrees C with slow cooling in 6-8 hrs; (g) heating to =70 degrees C and cooling to 20-25 degrees C in a cycle of 8-15 hrs. for 4-5 days; (h) boring and/or grading the casting. Prod. has higher mechanical loading capacity, e.g. improved by factor 3, a small reflection coefft. over widest possible frequency range and and smallest possible dimensions.</p> |
