1.報告會簡介
報告人：Jeffrey M. Wheeler（研究員）
時 間：2017年6月6日（星期二） 上午09：00（開始時間）
地 點： 友誼校區公字樓334
主 題： Combinatorial Micromechanics
內容簡介： Micromechanical testing has made significant progress in the last few decades. Advances in instrumentation and techniques have developed new geometries for measuring uniaxial strength and fracture toughness at very small length scales. In addition to increasing the test space envelope in terms of smaller sizes, the development of displacement controlled systems has allowed these properties to be investigated over a wide range of strain rates, even within single samples using strain rate jump and stress relaxation techniques. Using new, high speed actuators, the available test space has also been expanded to reach the high strain rate regime ( >103s-1). To complete the testing envelope, significant effort has been spent on achieving high temperature testing, and recently cryogenic temperature testing has also been achieved. By combining all these capabilities, the micromechanical testing envelope has grown to encompass a significant range of testing temperatures (-100 to 600 °C)and over eight orders of magnitude in strain rates (10-5to 103s-1).This creates the opportunity for plastic deformation mechanism mapping of materials at small scales over a wide range of homologous temperatures.
Diffusion couples have long been a fundamental technique in materials science, allowing the exploration of phase diagrams and diffusion constants. With the advent of the Materials Genome Initiative, diffusion couples and multiples are now being used as a high throughput means to investigate a wide range of materials properties. However, so far only the most fundamental micromechanical technique (nanoindentation) has been used to interrogate mechanical properties of diffusion couples. Here, the potential of applying advanced micromechanical techniques to diffusion couples will be demonstrated in the case of the Al-Cu binary system.
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黨委研究生工作部
材料學院
2017年6月2日
報告人簡介
Jeffrey Wheeler博士2005年本科畢業于美國伊利諾伊理工學院，2009年在英國劍橋大學拿到博士學位，隨后在英國劍橋大學高登實驗室開展博士后研究。2010年開始，在瑞士聯邦材料實驗室(EMPA)進行關低溫和高溫微納米力學設備的研發，同時利用先進表征手段研究材料在極端環境下的變形行為。2015年加入瑞士蘇黎士聯邦理工學院，成為材料學院納米冶金實驗室的研究員，目前主要關注共價鍵材料的的尺寸效應，以及溫度和應變速率敏感性。Wheeler研究員參與了多個研究項目，已發表51篇國際性期刊文章。
