| Abstract Scope |
We report the exceptional mechanical properties of aluminum-carbon (Al-C) thin films deposited by multiple source co-sputtering. First, a high-throughput combinatorial approach was taken to investigate mechanical and electrical properties of a blanket of Al-C thin film deposited with a compositional gradient. Hardness increased along with carbon addition, but at the cost of reduced electrical conductivity. These measurements allowed rapid screening of Al-C films, and showed that regions with ~ 6at% carbon possess a good balance of mechanical and electrical properties (2.8 GPa and 142 Ω⋅nm). Micro-tensile experiments of freestanding Al, Al-C 6.4at%, and Al-C 10.3at% films were conducted to acquire tensile properties and understand the strengthening mechanism. Al-C films with 6.4at% and 10.3at% carbon both exhibited significantly increased yield stress over 300 MPa while retaining ductility. In addition, an upper yield followed by drop in stress was observed in Al-C thin films which implies the formation of the Cottrell atmosphere. |