کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1524750 995341 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Copper viscoelasticity manifested in scratch recovery
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد مواد الکترونیکی، نوری و مغناطیسی
پیش نمایش صفحه اول مقاله
Copper viscoelasticity manifested in scratch recovery
چکیده انگلیسی

We have investigated two thick film copper compositions used in thermoelectric device fabrication. Dynamic mechanical analysis, thermal mechanical analysis, tensile testing, Vickers microhardness, optical microscopy and scratch testing were performed. The small grain samples have much smaller microindentation areas and much higher hardness than large grain samples, a consequence of intergranular spaces and thus low cohesion in large grain materials. The small grain material without intergranular spaces has higher linear thermal expansivity αL up to 150 °C; above that temperature negative αL is seen, a consequence of orientation relaxation. The large grain material also exhibits αL < 0 but only above 275 °C or so, a consequence of sintering. The small grain material has a storage modulus 49% higher than the large grain material over a wide temperature range, again an effect of high cohesion in the former. The brittleness value for the large grain material is 3.5 times larger than for the small grains material. Both kinds of materials exhibit recovery in scratch testing in the overall range of 23–36%—a manifestation of viscoelasticity.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Chemistry and Physics - Volume 124, Issue 1, 1 November 2010, Pages 371–376
نویسندگان
, , , ,