Evaporative Deposition of Aluminum Coatings and Shapes with Grain Size Control.

Jankowski, A. F. ; Hayes, J. P.

Technical Information Center Oak Ridge Tennessee

关键词: Aluminum coatings;    Deposition;    Physical vapor deposition;    Material behavior;    Profiles;   

RP-ID  :  DE200415007733

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

The direct deposition of coatings with variable cross-section profiles presents a challenge for the use of physical vapor deposition technology. Coatings with constant and variable cross-section profiles are of interest for advancing the evaluation of material behavior under extreme loading conditions, as for example under high strain rate. The synthesis of a variable cross-section profile by design in the as-deposited condition requires process innovation. It is demonstrated that a thickness gradient in cross-section can be produced when the substrate is exposed to a highly collimated evaporation source. The exposure is governed using a variable position shutter as driven by a computer-controlled stepper motor. An example is shown for aluminum deposition in which the coating thickness varies linearly from one plateau to another forming a wedge shape. To deposit a controlled grain size in coatings as these wedge shapes, first requires an understanding of the affect of time at temperature. An examination of aluminum coatings with constant cross-section reveals that ideal-grain growth behavior is observed from the micron-to-millimeter scale for depositions at temperatures in excess of half the melt point.