Applied pressure-dependent anisotropic grain connectivity in shock consolidated MgB2 samples

A novel approach for dynamic compaction of Mg–SiC nanocomposite powder using a modified Split Hopkinson Pressure Bar

“…Compaction stage can also be performed under different densification rates from quasi-static pressing [11,12] to dynamic compaction [13][14][15] and shock consolidation [16,17]. There are a large number of studies performed on quasi-static compaction [18,19] of powder, but less attention has been paid to dynamic compaction [20,21] or shock consolidation [22,23] techniques mainly because of more cost and complexity of latter techniques. In spite of the mentioned shortcomings, these procedures have some advantages over the quasi-static compaction methods.…”

Electromagnetic densification of MgB2/Cu wires

“…Underwater explosive shock consolidation and single-stage propellant gas gun densification methods resulted in ex situ MgB 2 bulks with mass densities of 2.41 and 2.39 g cm −3 , respectively, which are much higher than the 2.05 g cm −3 achieved with low rate densification by cold isostatic pressing (CIP) [13,14]. The ex situ MgB 2 bulk mass density resulting from underwater explosive shock consolidation was also reported to depend on the ratio of explosive to water and powder mass and values as high as 2.57 g cm −3 have been reported [15]. Samples prepared with the same powder but densified by 0.3 GPa CIP achieved only 2.2 g cm −3 .…”

“…High rate compaction has been recognized to have potential for use in processing superconducting powder materials. Most of the work has been done on explosive compaction of rods or cylinders of YBCO or BSCCO [9][10][11][12], and of MgB 2 powders [13][14][15][16][17][18][19]. Far fewer publications can be found on electromagnetic compaction of YBCO [11] and to the authors' knowledge, there is only one report of the electromagnetic compaction of MgB 2 powder [20].…”

“…Samples prepared with the same powder but densified by 0.3 GPa CIP achieved only 2.2 g cm −3 . The critical current density of these samples has been measured magnetically, but surprisingly very little difference between them was found, presumably arising from sample preparation in air and the lack of heat treatment after compression [15].…”

“…Unfortunately in [13][14][15][16][17][18][19] either no comparison to similar samples prepared by other compaction methods was made, or higher density samples did not show clearly a higher critical current density, so it is difficult to reach a definite conclusion about the effectiveness of dynamic compaction. Dynamically compacted samples were reported with different sequences of heat treatment and compression, and still the one leading to the best results needs to be identified.…”