Magnetic and tribological evaluation of metal particle and metal-evaporated tapes in a linear tape drive

Improving the performance of computer tape drives is an ongoing process tha t has recently involved the utilization of metal-evaporated (ME) tapes. The magnetic and tribological performance of the current metal particle (MP) t ape and a new dual-magnetic-layer ME tape were evaluated in a Quantum DLT 4 000 linear tape drive. Head output, drop-outs and head-tape interface frict ion were monitored during high-tension (1.7 N) high-speed (4 m/s) short-pas s (10 m) shuttling tests without stepping the head. The severe MP test neve r showed signs of failure, but wear of the head's outriggers is believed to impact the stability of the head output signal. MP tape significantly outp erformed ME tape; ME even performed poorly at nominal tension (0.8 N) and s peed (2.5 m/s) conditions. ME tape lubricant was stripped away by corners o n the DLT head, resulting in increased friction, wear and exposure of the r elatively brittle diamond-like carbon layer. A high-tension high-speed MP t est with head stepping was also performed to evaluate the effect of steppin g; it failed far sooner than the non-step MP test. The nominal ME test and severe MP head step test are both believed to have failed because of the dr ive's inability to overcome high (wear-induced) static friction experienced during changes in tape direction. Modifications to the existing head or a new head design could improve the performance of ME tape in the DLT 4000 li near tape drive.