mbt shoes ireland Elements Cr and La relative frag

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Elements Cr and La relative fragility of the impact of Fe2B


Radius of 1.85A, covalent radius of 1.18A). Impossible to form interstitial solid solution, so only replacement unit cell of Fe atoms. According to classical electron theory of solids and molecules bond length difference method described in [5], assuming that Cr in the lattice of Fe atoms displace. Calculation of Cr-containing FeB phase valence electron structure, find the weakest key B-B bond covalent electron pairs change. From the 0.1225 to 0.1313. The bond can also increase by the 3.9647kJ/mol 4.2950kJ/mo1. Using the same method to calculate the other bond. Found varying degrees of improvement. It can be said to exist in the form of substitution solid solution of Cr atoms Fe2B, changing the valence electron structure of FeB, can enhance the weakest bond and other bond energy,mbt shoes ireland, thereby reducing the brittle nature of Fe2B. 2.4La phase of the fracture toughness of Fe2B general. Material in the rare earth element can play a fine grain, cleaning grain boundaries, adsorption of impurities and so on, due to rare earth metal atoms and the atomic radius of radius quite different. Difficult to form a solid solution. Therefore, the role of alloying poor, but from the Fe. La phase diagram in the know. La rare earth elements in iron solubility smaller. Therefore,p90x workout schedule, in the solidification process is solid / liquid interface goes. Finally, sometimes enriched in dendritic grain boundaries, segregation at grain boundaries or phase boundaries, causing the interface structure and chemical composition changes, affecting the material properties. From the Cr-containing La and La-phase transmission micrographs (Figure 7) to see, Fe2B grain by grain composition of a large number of small sub. Rare earth material impact on the compounds it generally has a higher surface energy, easily absorbed into the grain boundaries, defects and other higher energy position. Resulting in the FeB phase samples containing La reasons for the increase of fracture toughness may be due to an extremely small amount of segregation to the Fe2B La phase diagram 7Fe. 8.8B. 3La transmission micrograph of Fig. 7TEMimageofFe a 8.8B-3La in the sub-boundaries,tory burch outlet, hindering the expansion of micro-cracks, thus increasing the fracture toughness Fe2B phase. 3 Conclusions (1) add an element of Cr and La intermetallic compound can reduce the brittle nature of Fe2B, Cr of the toughening effect was particularly notable. (2) Cr solid solution in the form of replacement in Fe2B, the change of valence electron structure Fe2B, largely to ease its brittle nature. References: [1] Xu Bin, Feng Chengming, Songyue Peng, et al. Solid chrome-boron rare earth permeation and Properties [J] l metal heat treatment, 1998, (6) :23-26. [2] UgurSen. Fracturetoughnessofboridesformedonboronizedductile iron [J]. MaterialsandDesign, 2005, (26) :175-179. [3] Li Mu-Sen, Xu Wandong, Zhang R L., et al. FeB phase valence electron structure and the nature of brittleness [J]. Acta Metallurgica Sinica, 1995,31 (5) :201-207. [4] Songyue Peng, Bin Xu, Hua Lei, et al. cr and RE elements on the brittleness of boride layer [J] l Physical and chemical testing a physical volumes, 2000,36 (5) :203-206. [5] Liu Zhilin, Li Zhilin, such as Weidong. Interface electronic structure and interface properties of [M]. Beijing: Science and Technology Press ,2002.11 -29; 222.239. Fields. ''''''''''''''''''''''''''''''''''''''',tory burch outlet,: Subscribe : : Main sections: overview of thermal engineering heating equipment; Industry News Technology Exchange:: flow of market information: Overseas Digest furnace materials technology: current market information; Overseas Digest furnace materials technology: Youfadaihao :52-41 bi-monthly: Price: 8 .00 per year: 48.00 yuan:: International Standard Serial Publication: ISSN1002-1639: Domestic Standard Serial publication: CN61.1208/TM: post offices across the country can subscribe to, but also mail order directly to the editorial department . : 2 Address: Zhuque Section 222 South Main Street: Zip: 710061 Tel / Fax: 029.85271255: Editor: Duan Qin:: website: http://www. gyjr. tom:; E-mail: gyjr @ pub. xaon1ine-c0Inigyjr @ chinajouma1. net. ca6 More articles related to topics：


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