[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-127005-en":3,"doc-seo-127005-105":30,"detail-sidebar-cat-0-en-105":91},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":4,"is_deleted":4,"is_public":20,"is_downloadable":20,"audit_status":20,"page_count":21,"language":22,"language_code":23,"site_id":24,"html_lang":23,"table_of_contents":25,"faqs":26,"seo_title":27,"seo_description":14,"update_tm":28,"read_time":29},127005,687207024643,"Oliver","https://ap-avatar.wpscdn.com/davatar_3d24733baf745e90a7e4bdd5f77d97b2",8,"Research & Report","Origin of the Yield Stress Anomaly in L1 2 Intermetallics - Unveiled with Physically-Informed Machine-Learning Potentials","Yield stress anomaly in L1 2 intermetallics such as Ni3Al and Ni3Ga is governed by the Kear-Wilsdorf lock (KWL), whose formation and unlocking depend on dislocation cross-slip. Molecular dynamics simulations use a physically-informed, active-learning machine-learning interatomic potential to model dislocation behavior in Ni3Al with near–ab initio fidelity. Simulations capture KWL formation and unlocking and reveal a strong temperature dependence of unlocking stress that contradicts existing analytical assumptions. A phenomenological model is proposed to fit atomistic unlocking stresses and extrapolate to macroscopic behavior, applicable to other L1 2 intermetallics.","arXiv :2406 .04948v1 [ cond-mat .mtrl-sci ] 7 Jun 2024  \nOrigin of the yield stress anomaly in L1 2 intermetallics unveiled with  \nphysically-informed machine-learning potentials  \nXiang Xu 1,2,* , Xi Zhang 1,* , Erik Bitzek3 , Siegfried Schmauder2 , and Blazej Grabowski 1  \n1 Institute for Materials Science, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany  \n2 Institute for Materials Testing, Materials Science and Strength of Materials, University of Stuttgart, Pfaffenwaldring 32, 70569 Stuttgart, Germany  \n3 Computational Materials Design, Max Planck Institute for Sustainable Materials, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.  \n* Emails: [xiang.xu@imw.uni-stuttgart.de](xiang.xu@imw.uni-stuttgart.de); [xi.zhang@imw.uni-stuttgart.de](xi.zhang@imw.uni-stuttgart.de)  \nAbstract  \nThe yield stress anomaly of L1 2 intermetallics such as Ni3 Al or Ni3 Ga is controlled by the so-called KearWilsdorf lock (KWL), of which the formation and unlocking are governed by dislocation cross-slip. Despite the importance of L1 2 intermetallics for strengthening Ni-based superalloys, microscopic understanding of the KWL is limited. Here, molecular dynamics simulations are conducted by employing a dedicated machine-learning interatomic potential derived via physically-informed active-learning. The potential facilitates modelling of the dislocation behavior in Ni3 Al with near ab initio accuracy. KWL formation and unlocking are observed and analyzed. The unlocking stress demonstrates a pronounced temperature dependence, contradicting the assumptions of existing analytical models. A phenomenological model is proposed to effectively describe the atomistic unlocking stresses and extrapolate them to the macroscopic scale. The model is general and applicable to other L1 2 intermetallics. The acquired knowledge of KWLs provides a deeper understanding on the origin of the yield stress anomaly.  \nKeywords: Yield stress anomaly; Dislocation cross-slip; L1 2 intermetallics; Molecular dynamics simulations; Machine-learning potentials.  \n1 Introduction  \nNi-based superalloys are used for turbine blades because they withstand thermal mechanical loadingsunder high turbine-entry temperatures [1 , 2] . Over several generations of these superalloys and corresponding thermal barrier coatings, the turbine-entry temperatures have increased by 700 K [3], significantly improving the thermodynamic efficiency of aircraft engines. The outstanding thermal resistance mainly originates from a high volume fraction of L1 2-ordered precipitates. In contrast to common structural materials, the yield stress of certain L1 2 intermetallics, e.g., Ni3 Al [4] or Ni3 Ga [5], increases with temperature, typically accompanied with an anomalously increasing work-hardening rate. As this so-called yield stress anomaly (YSA) is pivotal for strengthening advanced alloys, the steady increase of understanding YSA has been a key ingredient not only to the evolution of Ni-based superalloys [1 , 2 , 6] and Co-based superalloys [7–9], and also for the development of L1 2 strengthened high-entropy alloys [10 , 11] .  \nHowever, the origin of YSA is still not satisfactorily clarified [6] . What is known from transmission electron microscopy (TEM) on samples deformed in the temperature region of the YSA [12, 13] is that the dislocations in Ni3 Al exhibit a unique non-planar dislocation core structure—nowadays referred to asthe Kear-Wilsdorf lock (KWL) . The dislocation core was shown to evolve through cross-slip [14 , 15] in which three planar defects are involved: two antiphase boundaries (APBs) on the (100) and (111) planes plus a complex stacking fault (CSF) .  \nSeveral analytical models [16–22] have been proposed to comprehend KWLs and their relation to YSA, considering factors like the difference between the formation energies of the (111)APB and (100)APB [16],  \nand torque interactions between the superpartials [17] . The “APB-jump” phenomenon observed in in situ TEM e","cbCaisRgwx7BtJR9","https://ap.wps.com/l/cbCaisRgwx7BtJR9","pdf",34611111,1,22,"English","en",105,"# Introduction\n## Yield stress anomaly in L1 2 intermetallics\n## Kear-Wilsdorf lock and dislocation cross-slip\n## Limitations of existing analytical and atomistic models\n## Physically-informed machine-learning interatomic potentials\n## Study approach and dataset construction (DFT/MlIP)","[{\"question\":\"What controls the yield stress anomaly in L1 2 intermetallics like Ni3Al and Ni3Ga?\",\"answer\":\"It is controlled by the Kear-Wilsdorf lock (KWL), whose formation and unlocking are governed by dislocation cross-slip.\"},{\"question\":\"How are the dislocation processes studied in this work?\",\"answer\":\"The study performs molecular dynamics simulations using a dedicated machine-learning interatomic potential derived via physically-informed active learning, enabling near–ab initio accuracy.\"},{\"question\":\"What key finding challenges existing analytical models?\",\"answer\":\"The unlocking stress shows a pronounced temperature dependence, contradicting the assumptions of existing analytical models.\"}]","Origin of the Yield Stress Anomaly in L1 2 Intermetallics - Unveiled with Physically-Informed Machine-Learning Potentials | PDF",1785936228,55,{"code":4,"msg":31,"data":32},"ok",{"site_id":24,"language":23,"slug":33,"title":13,"keywords":34,"description":14,"schema_data":35,"social_meta":86,"head_meta":88,"extra_data":90,"updated_unix":28},"origin-of-the-yield-stress-anomaly-in-l1-2-intermetallics-unveiled-with-physically-informed-machine-learning-potentials","",{"@graph":36,"@context":85},[37,54,68],{"@type":38,"itemListElement":39},"BreadcrumbList",[40,44,48,51],{"item":41,"name":42,"@type":43,"position":20},"https://docshare.wps.com","Home","ListItem",{"item":45,"name":46,"@type":43,"position":47},"https://docshare.wps.com/document/","Document",2,{"item":49,"name":12,"@type":43,"position":50},"https://docshare.wps.com/document/research-report/",3,{"item":52,"name":13,"@type":43,"position":53},"https://docshare.wps.com/document/origin-of-the-yield-stress-anomaly-in-l1-2-intermetallics-unveiled-with-physically-informed-machine-learning-potentials/127005/",4,{"url":52,"name":13,"@type":55,"author":56,"headline":13,"publisher":58,"fileFormat":61,"inLanguage":23,"description":14,"dateModified":62,"datePublished":62,"encodingFormat":61,"isAccessibleForFree":63,"interactionStatistic":64},"DigitalDocument",{"name":9,"@type":57},"Person",{"url":41,"name":59,"@type":60},"DocShare","Organization","application/pdf","2026-08-05",true,{"@type":65,"interactionType":66,"userInteractionCount":4},"InteractionCounter",{"@type":67},"ViewAction",{"@type":69,"mainEntity":70},"FAQPage",[71,77,81],{"name":72,"@type":73,"acceptedAnswer":74},"What controls the yield stress anomaly in L1 2 intermetallics like Ni3Al and Ni3Ga?","Question",{"text":75,"@type":76},"It is controlled by the Kear-Wilsdorf lock (KWL), whose formation and unlocking are governed by dislocation cross-slip.","Answer",{"name":78,"@type":73,"acceptedAnswer":79},"How are the dislocation processes studied in this work?",{"text":80,"@type":76},"The study performs molecular dynamics simulations using a dedicated machine-learning interatomic potential derived via physically-informed active learning, enabling near–ab initio accuracy.",{"name":82,"@type":73,"acceptedAnswer":83},"What key finding challenges existing analytical models?",{"text":84,"@type":76},"The unlocking stress shows a pronounced temperature dependence, contradicting the assumptions of existing analytical models.","https://schema.org",{"og:url":52,"og:type":87,"og:title":13,"og:site_name":59,"og:description":14},"article",{"robots":89,"canonical":52},"index,follow",{"doc_id":7,"site_id":24},{"code":4,"msg":5,"data":92},[93,97,101,105,110,115,120,123,128,131,135],{"id":20,"doc_module":4,"doc_module_name":46,"category_name":94,"show_sort_weight":95,"slug":96},"Story & Novel",90,"story-novel",{"id":47,"doc_module":4,"doc_module_name":46,"category_name":98,"show_sort_weight":99,"slug":100},"Literature",80,"literature",{"id":53,"doc_module":4,"doc_module_name":46,"category_name":102,"show_sort_weight":103,"slug":104},"Exam",70,"exam",{"id":106,"doc_module":4,"doc_module_name":46,"category_name":107,"show_sort_weight":108,"slug":109},5,"Comic",60,"comic",{"id":111,"doc_module":4,"doc_module_name":46,"category_name":112,"show_sort_weight":113,"slug":114},6,"Technology",50,"technology",{"id":116,"doc_module":4,"doc_module_name":46,"category_name":117,"show_sort_weight":118,"slug":119},7,"Healthcare",40,"healthcare",{"id":11,"doc_module":4,"doc_module_name":46,"category_name":12,"show_sort_weight":121,"slug":122},30,"research-report",{"id":124,"doc_module":4,"doc_module_name":46,"category_name":125,"show_sort_weight":126,"slug":127},9,"Religion & Spirituality",20,"religion-spirituality",{"id":126,"doc_module":4,"doc_module_name":46,"category_name":129,"show_sort_weight":126,"slug":130},"World Cup","world-cup",{"id":132,"doc_module":4,"doc_module_name":46,"category_name":133,"show_sort_weight":132,"slug":134},10,"Lifestyle","lifestyle",{"id":136,"doc_module":4,"doc_module_name":46,"category_name":137,"show_sort_weight":106,"slug":138},19,"General","general"]