New discovery helps develop materials with higher strength and ductility

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Description

A research team comprising experts from City University of Hong Kong (CityU), University of Shanghai for Science and Technology (USST) and Zhejiang University (ZJU) discovered for the first time the deformation transitions of multiscale nanotwins (NTs) in austenitic stainless steel, which will help develop materials with higher strength and ductility.

Their research results have been published recently by the journal Nature Communications, in a paper titled “Scale law of complex deformation transitions of nanotwins in stainless steel”.

Period9 May 2019 → 15 May 2019

Media coverage

Title城大揭納米孿晶變形 助研更韌材料
Description金屬要同時兼具良好的延展性和強度向來非易事,但難題未來有望解決。城市大學、上海理工大學和浙江大學專家組成的研究團隊,探索納米孿晶變形行為的研究,首次揭示奧氏體不鏽鋼中多尺度納米孿晶的變形轉變,有助研發更高強度和延展性的材料。城大副校長(研究及科技)呂堅及其團隊,通過原位拉伸試驗,配合理論模型及分子動力學模擬,找出奧氏體不鏽鋼的納米孿晶變形轉變機制的臨界尺度,研究成果早前在科學期刊《自然通訊》上發表。
Persons
Media name/outletSing Tao Daily
PlaceHong Kong
Media typeWeb
Date15/05/19
Linkstd.stheadline.com/daily/article/detail/2004170-%E6%95%99%E8%82%B2-%E5%9F%8E%E5%A4%A7%E6%8F%AD%E7%B4%8D%E7%B1%B3%E5%AD%BF%E6%99%B6%E8%AE%8A%E5%BD%A2+%E5%8A%A9%E7%A0%94%E6%9B%B4%E9%9F%8C%E6%9D%90%E6%96%99
Title城大揭納米孿晶結構 助研更強物料
Description高強度和延展性的物料,是科學家一直追求的目標,一般而言,金屬的延展性會隨着強度增高而下降,反之亦然。不過科學家發現,納米孿晶(nanotwins, NTs)結構則大有潛力解決這個矛盾。城市大學領導的團隊,首次揭示不鏽鋼中納米孿晶的變形規律,對於研發更高強度和延展性的材料帶來重要啟示。

研究團隊由城大副校長(研究及科技)呂堅領導,城大、上海理工大學、浙江大學的專家組成,獲國家重點研發計劃和國家自然科學基金資助,有關成果以「不鏽鋼中納米孿晶變形轉變的尺度規律」為題,已經於科學期刊《自然通訊》上發表。
Persons
Media name/outletWen Wei Po
PlaceHong Kong
Media typeWeb
Date10/05/19
Linkpaper.wenweipo.com/2019/05/10/ED1905100007.htm
Title城大研究突破 助增金屬性能
Description金屬延展性隨強度增高而下降,科學家一直期望解決這個矛盾。由香港城市大學、上海理工大學、浙江大學專家組成的研究團隊,近日從被廣泛應用作工程材料的奥氏體不鏽鋼當中,首次揭示「納米孿晶」變形機制圖譜的臨界尺度,或有助日後通過納米孿晶結構研發更高強度和延展性的材料。


【明報專訊】金屬延展性隨強度增高而下降,科學家一直期望解決這個矛盾。由香港城市大學、上海理工大學、浙江大學專家組成的研究團隊,近日從被廣泛應用作工程材料的奥氏體不鏽鋼當中,首次揭示「納米孿晶」變形機制圖譜的臨界尺度,或有助日後通過納米孿晶結構研發更高強度和延展性的材料。

首揭納米孿晶變形臨界尺度

研究獲國家重點研發計劃和國家自然科學基金資助,城大副校長(研究及科技)呂堅及其團隊,結合實驗結果與理論研究,透過原位拉伸試驗,配合理論模型及分子動力學模擬,發現奧氏體不鏽鋼納米孿晶在尺度小於5納米、6至129納米之間,及大於129納米時,變形機制完全不同,其中在6至129納米之間,更會形成二級孿晶;有研究曾指出,孿晶級數愈高,強度也愈高,同時保持良好延展性。

城大副校長(研究及科技)呂堅表示,研究符合未來材料科學的發展方向,「納米孿晶不鏽鋼既是傳統合金又是納米結構合金,這次研究的新進展能提高傳統金屬材料的性能,同時有望提升高熵合金等新材料的特性」。研究成果已在科學期刊《自然通訊》上發表。
Persons
Media name/outletMing Pao
PlaceHong Kong
Media typeWeb
Date10/05/19
Linkhttps://news.mingpao.com/pns/%E6%95%99%E8%82%B2/article/20190510/s00011/1557426244387/%E5%9F%8E%E5%A4%A7%E7%A0%94%E7%A9%B6%E7%AA%81%E7%A0%B4-%E5%8A%A9%E5%A2%9E%E9%87%91%E5%B1%AC%E6%80%A7%E8%83%BD
TitleNew discovery helps develop materials with higher strength and ductility
DescriptionProfessor Lu Jian, CityU’s Vice-President (Research and Technology), and his team has discovered the marginal scale of nanotwin deformation transition mechanisms of austenitic stainless steel combining in situ tensile tests with theoretical modeling and atomistic simulations.

“We studied austenitic stainless steel because it’s a widely used engineering material,” Professor Lu said. “Our research results not only can serve as the basis for exploring a strengthening mechanism for other conventional metallic materials, but also help promoting the design and development of advanced materials with NTs.”

Members of the research team included Dr Sun Ligang from CityU, Dr Chen Aiying from USST, and Dr Zhu Linli from ZJU, who are current or previous members of Professor Lu’s research team at CityU. This research project was supported by the National Key Research and Development Programme of China and the General Programme of National Natural Science Foundation of China.
Persons
Media name/outletCityU NewsCentre
PlaceHong Kong
Media typeWeb
Date9/05/19
Linkhttps://newscentre.cityu.edu.hk/media/news/2019/05/09/new-discovery-helps-develop-materials-higher-strength-and-ductility