Wear testing of CVD diamond films

Boosting contact sliding and wear protection via atomic intermixing and tailoring of nanoscale interfaces

“…AES depth profiles for C/SiN x multilayer structures reveal the fluctuation of C, Si, and N intensities when moving away from the surface, approaching/crossing the C/SiN x interfaces, and reaching the film/substrate boundary, corroborating well with the actual designs of these multilayer structures. The immediate drop in C intensity and the immediate increase in O intensity in the first 50 s of most of the depth profiles after 5-Mm THW tests indicate that most of the head overcoats had been completely worn off, except in samples C, E, and M. Sample M with just a ~7- to 8-nm-thick overcoat displayed the best wear resistance (about 62% overcoat is still present after 5 Mm of THW) out of all the overcoats used in the present work and even surpasses the wear resistance of previously reported thicker and sputter-deposited ~20- to 100-nm coatings of CrN x , CrO x , CN x , c-BN, yttrium-stabilized ZrO 2 , W-C:H, a-C:H, Al 2 O 3 , and TiN ( 13 – 16 ).…”

“…At the same time, material wear is also a critical concern because the rapid removal and degradation of material result in early failure of various systems/devices (1)(2)(3). Magnetic storage devices, such as read/write heads, recording media of tape drives (TDs) and hard disk drives, probes for atomic force microscopy (AFM), micro-and nano-electromechancial systems (MEMS and NEMS), and many engineering scale components are some examples of MMSDs that suffer immensely from the adverse effects of wear and friction (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). In general, from environmental, human health, and economical viewpoints, even a small fraction of friction and wear reduction is vital for energy savings and increasing the operational lifetime of systems.…”

“…With miniaturization and advancement of modern devices/systems, the thickness budget of surface coatings in many devices and systems is shrinking year by year (4)(5)(6)(8)(9)(10)(11)(12)(13)(14)(15). However, most of the commonly used overcoats are very thick (from a few tens to hundreds of nanometers) (1,(13)(14)(15)(16)(17)(18)(19), provide insufficient wear durability in many rigorous tribological conditions (13)(14)(15)(16)(17)(18)(19), and hinder the intrinsic functionality of several practical systems and devices (4)(5)(6). For example, Erdemir et al (1) used a ~600-nm-thick overcoat to minimize friction and wear.…”

“…For example, Erdemir et al (1) used a ~600-nm-thick overcoat to minimize friction and wear. Among the widely used overcoats, namely, silicon nitride (SiN x ), chromium oxide (CrO x ), chromium nitride (CrN x ), amorphous carbon (a-C), zirconium oxides (ZrO 2 and Zr 2 O 3 ), and their various combinations, most of them suffer from excessive wear and friction despite being quite thick (10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Wear and friction issues are particularly critical for TDs owing to their contact recording architecture, where the recording head is always kept in contact with the tape media that slides across the head (9,(12)(13)(14)(15)(16)(17).…”

Analysis of residual stress in diamond films by x-ray diffraction and micro-Raman spectroscopy

“…6,14,15 The results generally show that the global intrinsic stress depends on the methane fraction, deposition temperature 6 and crystallographic orientation. 14 However, the understanding of residual stress formation in such films is incomplete and seems to be in a significant disagreement among various researchers as to the type and magnitude of the stress, even for similar deposition conditions.…”