Erdem YAŞAR, Osman ARMAĞAN, Talip KIRINDI, Merve Sultan AKAY AĞIR

Fe-30%Ni-%2.6Mo-X%Co Alaşımlarının Martensitik Faz Dönüşümünün ve Manyetik Özelliklerinin Araştırılması

Bu çalışmada, Fe-30%Ni-2.6%Mo-X%Co (X = 0.8, 1.8 ) alaşımında gözlenen termal etkili martensitik faz dönüşümünün mikro yapısı, taramalı elektron mikroskobu (SEM) ve geçirmeli elektron mikroskobu (TEM) kullanılarak morfolojik ve kristalografik olarak incelenmiştir. SEM çalışmalarında, alaşıma Co eklenmesiyle martensit fazın morfolojisinin iğnemsi ve merceksi yapıdan masif yapıya dönüştüğü gözlenmiştir. Bununla birlikte Co ilavesinin diğer bir etkisi olarak nano martensit oluşumu da görülmüştür (figure 2c, d). Lentiküler martensitin özellikleri, östenit ve martensit yapılarının elektron kırınım modeli TEM incelemeleri ile verilmiştir. Diferansiyel Taramalı Kalorimetre (DSC) analizlerine göre, alaşımlardaki Co miktarının artmasıyla martensitik dönüşüm sıcaklığının (Ms) önemli ölçüde arttığı belirlenmiştir. Ayrıca Mössbauer spektroskopisi kullanılarak Co miktarının artmasıyla martensit miktarının arttığı ve alaşımın manyetik düzeninin buna bağlı olarak değiştiği gösterilmiştir

Anahtar Kelimeler:

Termal etkili martensit, Kristalografik özellikler, Manyetik özellikler, TEM, SEM, Mössbauer Spektroskopisi

Investigation of Martensitic Phase Transformation and Magnetic Properties of Fe-30%Ni-2.6wt%Mo-X%Co Alloys

In this study, the microstructure of thermal effective martensitic phase transformation observed in the Fe-30wt.%Ni-2.6wt.%Mo-Xwt.%Co (X = 0.8, 1.8) alloy was investigated morphologically and crystallographically by using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). In SEM studies, it was observed that the morphology of the martensite phase changed from lath and lenticular structure to massive structure with the addition of Co to the alloy. In addition to this, nano martensite formation was also observed as another effect of Co addition (figure 2c, d). Properties of lenticular martensite, electron diffraction pattern of austenite and martensite structures were given by TEM studies. According to the Differential Scanning Calorimetry (DSC) analysis, it was determined that the martensitic transformation temperature (Ms) significantly increased with the increase of the Co amount in the alloys. Also, by using Mössbauer spectroscopy, it was shown that the amount of martensite increased with the increase of Co amount and the magnetic order of the alloy changed accordingly.

Keywords:

Thermally induced martensite, Crystallographic properties, Magnetic properties, TEM, SEM, Mössbauer spectroscopy,

PDF

___

[1] Maki T. 1990. Microstructure and Mechanical Behavior of Ferrous Martensite. Materials Science Forum, 56–58(1), 157–168. Doi:10.4028/www.scientific.net/MSF.56-58.157
[2] Maki T., Shimooka S., Fujiwara S. and Tamura I. 1975. Formation Temperature and Growth Behavior of Thin Plate Martensite in Fe-Ni-C Alloys. Materials Transactions JIM, 16(1), 35-41. Doi:0.2320/matertrans1960.16.35
[3] Shibata A., Murakami T., Morito S., Furuhara T., Maki T. 2008. The Origin of Midrib in Lenticular Martensite. Materials Transactions, 49(6), 1242-1248. Doi:10.2320/matertrans.MRA2007296
[4] Yaşar E., Erdem U., Tuna M. A., Armağan O. and Kırındı T. 2018. The Effect of Ti Content on α’ Martensite Phase Transformation, and Magnetic Properties by Mossbauer Spectroscopy in Fe–30%Ni–X%Ti (wt%) Alloys. Acta Physica Polonica A, 133(4), 497-501. Doi: 10.12693/APhysPolA.133.1165
[5] Patterson R. L., Wayman G. M. 1966. The Crystallography and Growth of Partially-Twinned Martensite Plates in Fe-Ni Alloys. Acta Metallurgica, 14(3), 347-369. Doi: 10.1016/0001-6160(66)90094-0
[6] Tanaka Y., Himuro Y., Omori T., Sutou Y., Kainuma R., et al. 2006. Martensitic Transformation and Shape Memory Effect in Ausaged Fe–Ni–Si–Co Alloys. Materials Science and Engineering A, 438-440(2), 1030-1035. Doi: 10.1016/ j.msea. 2006.02.103
[7] Shibata A., Morito S., Furuhara T., Maki T. 2009. Substructures of Lenticular Martensites with Different Martensite Start Temperatures in Ferrous Alloys. Acta Materialia, 57(2), 483-492. Doi:10.1016/j.actamat.2008.09.030
[8] Yasar E., Gungunes H., Kilic A., Durlu T. N. 2006. Effect of Mo on the Magnetic Properties of Martensitic Phase in Fe–Ni–Mo Alloys. Journal of Alloys and Compounds, 424, 51–54. Doi:10.1016/j.jallcom.2005.12.075
[9] Takaki S., Nakatsu H., Tokunaga Y. 1993. Effects of Austenite Grain Size on ε Martensitic Transformation in Fe-15mass%Mn Alloy. Materials Transactions JIM, 34(6), 489-495. Doi:10.2320/matertrans1989.34.489
[10] Maki T., Tamura I. 1984. On the Thin Plate Martensite in Ferrous Alloys and It's Various Properties. Bulletin of the Japan Institute of Metals, 23(4), 229-237. Doi:10.2320/materia1962.23.229
[11] Maki T., Wayman C. M. 1976. Substructure of Ausformed Martensite in Fe-Ni and Fe-Ni-C Alloys. Metallurgical Transactions A, (7), 1511–1518. Doi:10.1007/BF02656393
[12] Shibata A., Furuhara T., Maki T. 2010. Interphase Boundary Structure and Accommodation Mechanism of Lenticular Martensite in Fe–Ni Alloys. Acta Materialia, 58(9), 3477-3492. Doi: 10.1016/j.actamat.2010.02.022
[13] Shibata A., Morito S., Furuhara T., Maki T. 2005. Local Orientation Change İnside Lenticular Martensite Plate in Fe–33Ni Alloy. Scripta Materialia, 53(5), 597-602. Doi:10.1016/j.scriptamat.2005.04.023
[14] Shibata A., Murakami T., Morito S., Furuhara T. and Maki T. 2008. The Origin of Midrib in Lenticular Martensite. Journal of the Japan Institute of Metal, 49(6), 1242-1248. Doi: 10.2320/matertrans.MRA2007296
[15] Nishiyama, Z., 1978. Martensitic Transformations, Academic Press., New York.
[16] Kırındı T., Sarı U. 2009. Influence of Mn Content on the Magnetic Properties and Microstructure in Fe–Mn–Mo Alloys. Journal of Alloys and Compounds, 488, 129–133. Doi:10.1016/j.jallcom.2009.09.004
[17] Yang J. H., Chen H., Wayman C. M. 1992. Development of Iron Based Shape Memory Alloys Associated with FCC to HCP Martensitic Transformations: Part II, Transformation Behavior. Metallurgical Transactions A, 23, 1439–1444. Doi:10.1007/BF02647327
[18] Mizrahi M., Cabrera A. F., Cotes S. M., Stewart S. J., Mercader R. C., et al. 2004. Distribution of Mn Atoms in a Substitutional bcc-FeMn Solid Solution. Hyperfine Interactions, 156/157, 541–545. Doi:10.1007/978-1-4020-2852-6_78
[19] Cotes S. M., Cabrera A. F., Damonte L. C., Mercader R. C., Desimoni J. 2002. Phase Transformations in Fe–Mn Alloys Induced by Ball Milling. Hyperfine Interactions, 141/142, 409–414. Doi: 10.1023/A:1021204909505
[20] Panissod, P. 1985. Studies of the Electronic and Atomic Structure of Amorphous Metals by NMR. Helvetica Physica Acta, 58, 60-75. Doi: 10.5169/seals-115580
[21] Panissod P., Durand J. and Budnick J. I. 1982. Hyperfine Fields in Metallic Glasses. Nuclear Instruments and Methods in Physics Research, 199, 1-2, 99-114. Doi: 10.1016/0167-5087(82)90180-6
[22] Yamauchi K. and Mizoguchi T. 1975. The Magnetic Moments of Amorphous Metal-Metalloid Alloys. Journal of the Physical Society Japan, 39, 541-542. Doi: 10.1143/JPSJ.39.541
[23] Yang H. S. and Bhadeshia H. K. D. H. 2009. Austenite Grain Size and the Martensite–Start Temperature. Scripta Materialia, 60, 493–495. Doi: 10.1016/j.scriptamat.2008.11.043