{"title":"Cu44.25Ag14.75Zr36Ti5 和 Ti32.8Zr30.2Cu9Ni5.3Be22.7 脆性 BMG 在过冷液体区的流变行为","authors":"","doi":"10.1016/j.jnoncrysol.2024.123210","DOIUrl":null,"url":null,"abstract":"<div><p>Bulk metallic glasses (BMGs) show limited plasticity at room temperature. However, BMGs usually exhibit superplasticity and high plastic forming ability in their supercooled liquid region (SLR). The rheological behavior of BMGs in SLR is vitally important to their thermoplastic forming process. In contrast to the ductile BMGs, thermoplastic deformation behavior of brittle BMGs is rarely reported. In present work, the rheological behavior of two brittle BMGs with high glass forming ability Cu<sub>44.25</sub>Ag<sub>14.75</sub>Zr<sub>36</sub>Ti<sub>5</sub> and Ti<sub>32.8</sub>Zr<sub>30.2</sub>Cu<sub>9</sub>Ni<sub>5.3</sub>Be<sub>22.7</sub> was investigated on Gleeble3500. The two BMGs can deform homogeneously depending on the temperature and strain rate. According to the high value of m (strain rate sensitivity index), which is the most important mechanical characteristic of a superplastic material, the two BMGs show superplasticity in their SLR with <em>m</em> ≥ 0.3. Based on the free volume model, their activation volumes are calculated as 0.263∼0.486 nm<sup>3</sup> and 1.261∼1.650 nm<sup>3</sup>, indicating the minimum displacement clusters with average 26∼48 and 91∼127 atoms, for Cu<sub>44.25</sub>Ag<sub>14.75</sub>Zr<sub>36</sub>Ti<sub>5</sub> and Ti<sub>32.8</sub>Zr<sub>30.2</sub>Cu<sub>9</sub>Ni<sub>5.3</sub>Be<sub>22.7</sub>, respectively. Thus, the two investigated brittle BMGs can be thermoplastic processed in the SLR and the deformation maps are given. BMG Cu<sub>44.25</sub>Ag<sub>14.75</sub>Zr<sub>36</sub>Ti<sub>5</sub> shows better machinable property than Ti<sub>32.8</sub>Zr<sub>30.2</sub>Cu<sub>9</sub>Ni<sub>5.3</sub>Be<sub>22.7</sub>. Compared to the ductile BMGs, no Newtonian flow is found for the two investigated brittle BMGs.</p></div>","PeriodicalId":16461,"journal":{"name":"Journal of Non-crystalline Solids","volume":null,"pages":null},"PeriodicalIF":3.2000,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The rheological behavior of brittle BMGs of Cu44.25Ag14.75Zr36Ti5 and Ti32.8Zr30.2Cu9Ni5.3Be22.7 in the supercooled liquid region\",\"authors\":\"\",\"doi\":\"10.1016/j.jnoncrysol.2024.123210\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Bulk metallic glasses (BMGs) show limited plasticity at room temperature. However, BMGs usually exhibit superplasticity and high plastic forming ability in their supercooled liquid region (SLR). The rheological behavior of BMGs in SLR is vitally important to their thermoplastic forming process. In contrast to the ductile BMGs, thermoplastic deformation behavior of brittle BMGs is rarely reported. In present work, the rheological behavior of two brittle BMGs with high glass forming ability Cu<sub>44.25</sub>Ag<sub>14.75</sub>Zr<sub>36</sub>Ti<sub>5</sub> and Ti<sub>32.8</sub>Zr<sub>30.2</sub>Cu<sub>9</sub>Ni<sub>5.3</sub>Be<sub>22.7</sub> was investigated on Gleeble3500. The two BMGs can deform homogeneously depending on the temperature and strain rate. According to the high value of m (strain rate sensitivity index), which is the most important mechanical characteristic of a superplastic material, the two BMGs show superplasticity in their SLR with <em>m</em> ≥ 0.3. Based on the free volume model, their activation volumes are calculated as 0.263∼0.486 nm<sup>3</sup> and 1.261∼1.650 nm<sup>3</sup>, indicating the minimum displacement clusters with average 26∼48 and 91∼127 atoms, for Cu<sub>44.25</sub>Ag<sub>14.75</sub>Zr<sub>36</sub>Ti<sub>5</sub> and Ti<sub>32.8</sub>Zr<sub>30.2</sub>Cu<sub>9</sub>Ni<sub>5.3</sub>Be<sub>22.7</sub>, respectively. Thus, the two investigated brittle BMGs can be thermoplastic processed in the SLR and the deformation maps are given. BMG Cu<sub>44.25</sub>Ag<sub>14.75</sub>Zr<sub>36</sub>Ti<sub>5</sub> shows better machinable property than Ti<sub>32.8</sub>Zr<sub>30.2</sub>Cu<sub>9</sub>Ni<sub>5.3</sub>Be<sub>22.7</sub>. Compared to the ductile BMGs, no Newtonian flow is found for the two investigated brittle BMGs.</p></div>\",\"PeriodicalId\":16461,\"journal\":{\"name\":\"Journal of Non-crystalline Solids\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.2000,\"publicationDate\":\"2024-09-07\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Non-crystalline Solids\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0022309324003879\",\"RegionNum\":3,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATERIALS SCIENCE, CERAMICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Non-crystalline Solids","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022309324003879","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
The rheological behavior of brittle BMGs of Cu44.25Ag14.75Zr36Ti5 and Ti32.8Zr30.2Cu9Ni5.3Be22.7 in the supercooled liquid region
Bulk metallic glasses (BMGs) show limited plasticity at room temperature. However, BMGs usually exhibit superplasticity and high plastic forming ability in their supercooled liquid region (SLR). The rheological behavior of BMGs in SLR is vitally important to their thermoplastic forming process. In contrast to the ductile BMGs, thermoplastic deformation behavior of brittle BMGs is rarely reported. In present work, the rheological behavior of two brittle BMGs with high glass forming ability Cu44.25Ag14.75Zr36Ti5 and Ti32.8Zr30.2Cu9Ni5.3Be22.7 was investigated on Gleeble3500. The two BMGs can deform homogeneously depending on the temperature and strain rate. According to the high value of m (strain rate sensitivity index), which is the most important mechanical characteristic of a superplastic material, the two BMGs show superplasticity in their SLR with m ≥ 0.3. Based on the free volume model, their activation volumes are calculated as 0.263∼0.486 nm3 and 1.261∼1.650 nm3, indicating the minimum displacement clusters with average 26∼48 and 91∼127 atoms, for Cu44.25Ag14.75Zr36Ti5 and Ti32.8Zr30.2Cu9Ni5.3Be22.7, respectively. Thus, the two investigated brittle BMGs can be thermoplastic processed in the SLR and the deformation maps are given. BMG Cu44.25Ag14.75Zr36Ti5 shows better machinable property than Ti32.8Zr30.2Cu9Ni5.3Be22.7. Compared to the ductile BMGs, no Newtonian flow is found for the two investigated brittle BMGs.
期刊介绍:
The Journal of Non-Crystalline Solids publishes review articles, research papers, and Letters to the Editor on amorphous and glassy materials, including inorganic, organic, polymeric, hybrid and metallic systems. Papers on partially glassy materials, such as glass-ceramics and glass-matrix composites, and papers involving the liquid state are also included in so far as the properties of the liquid are relevant for the formation of the solid.
In all cases the papers must demonstrate both novelty and importance to the field, by way of significant advances in understanding or application of non-crystalline solids; in the case of Letters, a compelling case must also be made for expedited handling.