Philipp Maas , Yuta Mizumoto , Yasuhiro Kakinuma , Sangkee Min
{"title":"正交切割和纳米压痕实验中单晶蓝宝石的各向异性脆-韧转变","authors":"Philipp Maas , Yuta Mizumoto , Yasuhiro Kakinuma , Sangkee Min","doi":"10.1016/j.npe.2018.09.005","DOIUrl":null,"url":null,"abstract":"<div><p>Single-crystal sapphire is utilized as a high-performance engineering material, especially in extreme and harsh environments. However, due to its extreme hardness and brittleness, the machinability of sapphire is still a challenge. By means of nanoindentation and plunge-cut experiments, the anisotropic brittle-ductile transition of the prismatic M-plane and rhombohedral R-plane is examined by analyzing crack morphologies and the critical depth-of-cut (CDC). The experimental results of the nanoindentation tests are correlated to the plunge-cut experiment. Both the prism plane and the rhombohedral crystal plane exhibit a two-fold symmetry of ductility with various crack patterns along the machined grooves. The direction-dependent plasticity of the hexagonal sapphire crystal is mainly connected to a twinning process accompanied by slip dislocation.</p></div>","PeriodicalId":87330,"journal":{"name":"Nanotechnology and Precision Engineering","volume":"1 3","pages":"Pages 157-171"},"PeriodicalIF":0.0000,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.npe.2018.09.005","citationCount":"13","resultStr":"{\"title\":\"Anisotropic brittle-ductile transition of monocrystalline sapphire during orthogonal cutting and nanoindentation experiments\",\"authors\":\"Philipp Maas , Yuta Mizumoto , Yasuhiro Kakinuma , Sangkee Min\",\"doi\":\"10.1016/j.npe.2018.09.005\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Single-crystal sapphire is utilized as a high-performance engineering material, especially in extreme and harsh environments. However, due to its extreme hardness and brittleness, the machinability of sapphire is still a challenge. By means of nanoindentation and plunge-cut experiments, the anisotropic brittle-ductile transition of the prismatic M-plane and rhombohedral R-plane is examined by analyzing crack morphologies and the critical depth-of-cut (CDC). The experimental results of the nanoindentation tests are correlated to the plunge-cut experiment. Both the prism plane and the rhombohedral crystal plane exhibit a two-fold symmetry of ductility with various crack patterns along the machined grooves. The direction-dependent plasticity of the hexagonal sapphire crystal is mainly connected to a twinning process accompanied by slip dislocation.</p></div>\",\"PeriodicalId\":87330,\"journal\":{\"name\":\"Nanotechnology and Precision Engineering\",\"volume\":\"1 3\",\"pages\":\"Pages 157-171\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2018-09-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.npe.2018.09.005\",\"citationCount\":\"13\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Nanotechnology and Precision Engineering\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2589554018300072\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nanotechnology and Precision Engineering","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2589554018300072","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Anisotropic brittle-ductile transition of monocrystalline sapphire during orthogonal cutting and nanoindentation experiments
Single-crystal sapphire is utilized as a high-performance engineering material, especially in extreme and harsh environments. However, due to its extreme hardness and brittleness, the machinability of sapphire is still a challenge. By means of nanoindentation and plunge-cut experiments, the anisotropic brittle-ductile transition of the prismatic M-plane and rhombohedral R-plane is examined by analyzing crack morphologies and the critical depth-of-cut (CDC). The experimental results of the nanoindentation tests are correlated to the plunge-cut experiment. Both the prism plane and the rhombohedral crystal plane exhibit a two-fold symmetry of ductility with various crack patterns along the machined grooves. The direction-dependent plasticity of the hexagonal sapphire crystal is mainly connected to a twinning process accompanied by slip dislocation.