Preliminary Report on Scientific Work on "Fletcher's Ice Island", T3

"T3 is an ice island in the Arctic Ocean on which a permanent campsite was erected in 1952 for scientific operations. The investigations, other than meteorological, in progress from April 1-Oct. 1, included studies of the physical structure of the island, the movement of the island and the ice pack, seismic profiling and other miscellaneous data. T3 is 31 mi in circumference and has a minimum width of 5 mi. A 52-ft hole was dug in which 58 dirt layers were found, the contents of which were weighed and microscopically examined. Lakes appeared in the hollows during the thaw period (late June to mid-Aug.). A map presents the track of T3, indicating the changes of island azimuth to true and magnetic north and the geographical longitudes. A tentative ice thickness of about 160 ft was obtained through seismic soundings of the ice and the ocean bottom. Ocean depths ranging from 5000-12,000 ft were obtained."--SIPRE. Samples of surface dirt, flora and fauna were collected, including large boulders of granitic rock, plant fragments (stems, leaves, blossoms), mollusc shells, fishbones, caribou antlers, etc. A few birds and bear and arctic fox tracks were seen. Continuing research on T-3 is indicated

Hybrid HIPIMS and DC magnetron sputtering deposition of TiN coatings: Deposition rate, structure and tribological properties

High power impulse magnetron sputtering (HIPIMS) has the advantage of ultra-dense plasma deposition environment although the resultant deposition rate is significantly low. By using a closed field unbalanced magnetron sputtering system, a hybrid process consisting of one HIPIMS powered magnetron and three DC magnetrons has been introduced in the reactive sputtering deposition of a TiN hard coating on a hardened steel substrate, to investigate the effect of HIPIMS incorporation on the deposition rate and on the microstructure and mechanical and tribological properties of the deposited coating. Various characterizations and tests have been applied in the study, including XRD, FEG-SEM, cross-sectional TEM, Knoop hardness, adhesion tests and unlubricated ball-on-disk tribo-tests. The results revealed that, both the DC magnetron and hybrid-sputtered TiN coatings exhibited dense columnar morphology, a single NaCl-type cubic crystalline phase with strong (220) texture, and good adhesion property. The two coatings showed similar dry sliding friction coefficient of 0.8 – 0.9 and comparable wear coefficient in the range of 1 – 2× 10-15 m3N-1m-1. The overall deposition rate of the hybrid sputtering, being 0.047 μm/min as measured in this study, was governed predominantly by the three DC magnetrons whereas the HIPIMS only made a marginal contribution. However, the incorporated HIPIMS has been found to lead to remarkable reduction of the compressive residual stress from -6.0 to -3.5 GPa and a slight increase in the coating hardness from 34.8 to 38.0 GPa