A METHOD FOR MECHANICAL CHARACTERIZATION OF COLD SPRAY SPUTTER TARGETS IN PV MANUFACTURING

In order to ensure a reliable performance of cold-sprayed sputter targets, mechanical characterization of the as-sprayed deposit is essential. The rotary target geometry poses challenges for conventional tensile testing. Indentation testing techniques are also inadequate due to the inherent limitation in attending to the distribution of microstructure and flaws in the as sprayed deposit.

In this work the Brazilian disc test technique is applied to mechanical characterization of cold-sprayed Cu-In-Ga deposits. The main advantage of the test is that the material can be tested in its end product form while naturally attending to the distribution of micro-structural phases and flaws by choosing an appropriate specimen size. The stress state of the test specimen can be obtained in analytical closed form and testing can be readily extended to examine temperature dependence of material properties as well as obtaining the full stress-strain curve.