Hardness, Young’s Modulus and Elastic Recovery in Magnetron Sputtered Amorphous AlMgB14 Films

Abstract

We report optical and mechanical properties of hard aluminum magnesium boride films magnetron sputtered from a stoichiometric AlMgB14 ceramic target onto Corning® 1737 Glass and Si (100) wafers. High target sputtering rf-power and sufficiently short target-to-substrate distance appeared to be critical processing conditions. Amorphous AlMgB14 films demonstrate very strong indentation size effect (ISE): exceptionally high nanohardness H = 88 GPa and elastic Young’s modulus E* = 517 GPa at 26 nm of the diamond probe penetration depth and almost constant values, respectively, of about 35 GPa and 275 GPa starting at depths of about 2–3% of films’ thickness. For comparative analysis of elastic strain to failure index H/E*, resistance to plastic deformation ratio H3/E*2 and elastic recovery ratio We were obtained in nanoindentation tests performed in a wide range of loading forces from 0.5 to 40 mN. High authentic numerical values of H = 50 GPa and E* = 340 GPa correlate with as low as only 10% of total energy dissipating through the plastic deformations.

A further look at the nano/micro-indentation method for measuring and ranking Young’s modulus and hardness of materials

“…It is well known that the indentation load affects the hardness measurement; the indentation hardness increases with decreasing the indentation depth [16][17][18]. The situation is similar to the Young's modulus measurement [19]. Such phenomena are related to plastic deformations or dislocation generation in alloys during indentation [20][21][22][23].…”

“…However, ceramic materials are generally brittle with little or rather limited plasticity, so that the influence of cracking or fracture on the results of indentation measurement is not unexpected [28]. For Young's modulus, the reason for the decreased value with increasing the indentation load is not very clear [19,29,30]. The change in Young's modulus may not be obvious for ductile or less brittle materials [31][32][33].…”

Indentation and abrasion in glass products: Lessons learned and yet to be learned

“…These values lead to a ratio H/E > .1 indicating a superior tribological resistance. 102 Transportation damage can be proactively reduced by using cell packaging. Many glass products are shipped across long distances in stretch-wrapped packages, sometimes stacked on each other, where the items forcefully touch each other.…”

“…The characteristics of this class of coating materials are hardness with typical values around 30 GPa, and elastic modulus E ≈ 200–300 GPa. These values lead to a ratio H / E > .1 indicating a superior tribological resistance 102 …”

Structure and flexural strength of the hot-pressed AlMgB14 ceramic

“…At present time, the main interest of various research groups mainly focused on the studying of the structure and phase composition formation mechanisms of AlMgB 14 -based materials, as well as tribological properties and hardness of this materials and coating based on them [2,[7][8][9][10]. A number of approaches have been proposed for the synthesis of the initial AlMgB 14 -powder and bulk materials following sintering in the hightemperature furnaces, self-propagating high-temperature synthesis (SHS), hot pressing, and spark plasma sintering [11][12][13].…”