Effect Of Sintering Temperature On The Rolled Copper-Sheathed Monofilament MgB2 Superconducting Wire

The manufacture of low temperature superconductor (LTS) MgB2 with relatively high critical temperature(Tc = 39K) wire fabricated by powder-in-tube (PIT) is a multi-step process. The main difficulty is that the value ofTc superconductor wire is determined by various factors. MgB2 superconductor has been developed for possibleutilization in various practical applications, such as Magnetic Resonance Imaging. The fabrication process of 2 mmrolled-copper sheath monofilament superconductor MgB2 wire using mechanical deformation process, includingrolling and drawing, has been carried out. Starting by inserting powders, containing nominal composition of MgB2into Cu tube with inner ø of 4 mm and outer ø of 6 mm, then they were rolled and drawn into wires (ø 2 mm),subsequently. The process of copper tube rolling was subsequently repeated in order to obtain three samples usingadded 5 persen CNT and 10 persen CNT to the pure MgB2, then were heat-treated at 800°C for 2 hours respectively. Thewriters evaluated the doping effect of two types multiwall carbon nanotube (MWCNT) with different aspect ratioson MgB2/Cu monofilament wires. Surface morphology was analyzed with SEM, crystal structure of MgB2 withXRD, whereas temperature dependence resistivity with four-point probe Cryogenic Magnet. SEM-EDS imagesshowed that without addition of CNT, the crystal of MgB2 form dispersed uniformly in wire, but when added with5 persen and 10 persen of CNT, the particle dispersed morphology was observed due to substitution of atom C into atom B.In contrast with pure MgB2, however, the pores increased as the CNTs doped increased of up to 5 wt persen, makes ithard to identify the critical temperature. The temperature dependence of resistivity results showed that the criticaltemperatures were detected and kept shifting toward high 40 K with the addition of 10 wt persen CNT. XRD analysisshowed that some Mg may react with CNT to form MgB4 and graphite. Mg may react with oxygen to form MgObecause the Cu sheath is not fully sealed and vacuumed. Jurnal Teknologi Indonesia 40 (1) 2017: 31–35