کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5457907 | 1515956 | 2017 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Fatigue testing and properties of hardmetals in the gigacycle range
ترجمه فارسی عنوان
تست خستگی و خواص سختی فلز در محدوده دگرگونی
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
فلزات و آلیاژها
چکیده انگلیسی
Hardmetal products are frequently fatigue loaded in service, such as e.g. cutting tools for milling or percussion drills. In the present work, the fatigue behaviour of hardmetals was investigated into the gigacycle range using ultrasonic resonance fatigue testing at 20 kHz in push-pull mode at R = â 1. Liquid cooling was afforded using water with addition of a corrosion inhibitor. Hourglass shaped specimens were prepared, the surface being ground and polished with subsequent stress-relieving anneal to remove the high compressive residual stresses introduced during grinding. S-N curves with fairly low scatter were obtained, which indicates microstructure-controlled and not defect-controlled failure. Low binder content as well as fine WC grains were found to improve the fatigue endurance strength. In no case, however, a horizontal branch of the S-N curve was observed, i.e. there is no fatigue “limit” at least up to 1010 cycles. The initiation sites were in part difficult to identify; in such cases when the site was clearly visible, decohesion of the binder from large WC grains seems to have caused crack initiation. This further corroborates that microstructural features and not singular defects as e.g. inclusions are the initiation sites, which underlines the high purity of the hardmetal grades used. Based on fracture mechanical consideration a damage diagram was determined allowing to deduce critical defect sizes.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Refractory Metals and Hard Materials - Volume 62, Part B, January 2017, Pages 183-191
Journal: International Journal of Refractory Metals and Hard Materials - Volume 62, Part B, January 2017, Pages 183-191
نویسندگان
Agnieszka Betzwar Kotas, Herbert Danninger, Brigitte Weiss, Ken Mingard, Jose Sanchez, Luis Llanes,