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S.K. Kemei, M.S.K. Kirui, F.G. Ndiritu, R.G. Ngumbu, P.M. Odhiambo, D.M.G. Leite, A.L.J. Pereira and J.H. Dias Da Silva

Abstract

Dynamical mechanical analysis yields information about the mechanical properties of a material as a function of deforming factors, such as temperature, oscillating stress and strain amplitudes. GaAs and Mn-doped GaAs at varied levels, used in making electronic devices, suffer from damage due to changes in environmental temperatures. This is a defective factor experienced during winter and summer seasons. Hence, there was a need to establish the best amount of manganese to be doped in GaAs so as to obtain a mechanically stable spin injector material to make electronic devices. Mechanical properties of Ga1-xMnxAs spin injector were studied in relation to temperatures above room temperature (25 °C). Here, creep compliance, Young’s moduli and creep recovery for all studied samples with different manganese doping levels (MDLs) were determined using DMA 2980 Instrument from TA instruments Inc. The study was conducted using displace-recover programme on DMA creep mode with a single cantilever clamp. The samples were prepared using RF sputtering techniques. From the creep compliance study it was found that MDL of 10 % was appropriate at 30 °C and 40 °C. The data obtained can be useful to the spintronic and electronic device engineers in designing the appropriate devices to use at 30 °C and above or equal to 40 °C.

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N. Zienkiewicz, J. Paradowska, W. Serbiński, G. Gajowiec, A. Hernik and A. Zieliński

Abstract

The purpose of the present research was to determine the oxidation and hydrogenation behavior in the new Zr-2Mn alloy. The oxidation of alloy was performed at temperatures between 350°C and 900°C for 30 minutes. The hydrogen charging was made for 72 h at a current density 80 mA/cm2. The charged samples were heat treated at 400°C for 4 h to obtain a uniform hydrogen profile content across the sample. The oxidation resulted in an appearance of non-uniform oxide layers of thickness increasing with temperature. The surface damage was observed at higher temperatures 700 and 900°C. After charging with hydrogen followed by annealing no hydrides were found. The observed effect is evidence that the oxide layers may form effective barriers against hydrogen diffusion even if they are partially degraded. The absence of hydrides or hydride cracking may be caused by an absence in Zr-Mn alloys of such phase precipitates, which may trap diffusive hydrogen and initiate the hydrides. The positive influence of manganese on the formation of the thick oxide layer and relative resistance to delayed hydride cracking may be attributed to its affinity of oxygen, the ability to form thick and compact oxide layers during oxidation, the formation of solid solution in zirconium and no precipitates enhancing nucleation of hydrides.

Open access

T. Lipiński, A. Wach and E. Detyna

Abstract

The article discusses the effect of large oxide impurities (a diameter larger than 10 μm in size) on the fatigue resistance of structural steel of high purity during rotary bending. The study was performed on 7 heats produced in an industrial plant. The heats were produced in 140 ton electric furnaces. All heats were desulfurized.

The experimental material consisted of semi-finished products of high-grade, carbon structural steel with: manganese, chromium, nickel, molybdenum and boron. Steel sections with a diameter of 18 mm were hardened from austenitizing by 30 minutes in temperature 880°C and tempered at a temperature of 200, 300, 400, 500 and 600°C for 120 minutes and air-cooled. The experimental variants were compared in view of the heat treatment options. Fatigue tests were performed with the use of a rotary bending machine at a frequency of 6000 cpm. The results were statistical processed and presented in graphic form.

This paper discusses the results of the relative volume of large impurities, the fatigue strength for various heat processing options.

Open access

M. Szkodo

. Szkodo M.: Cavitation erosion behaviour of 18/8 stainless steel after its laser alloying of manganese. Solid State Phenomena 113 (2006), pp.513-516. Heathcock C. J., Protheroe B. E., Ball A.: Cavitation of stainless steels. Wear 81 (1982), pp. 311-327. Fu W. T., Yang Y. B., Jing T. F., Zheng Y. Z., Yao M.: The resistance to cavitation erosion of Cr-Mn-N stainless steels. J. Mater. Sci. Perform. 7 (1998), pp. 801-804. Mills D. J., Knutsen R. D.: An investigation of the tribological

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W. Serbiński, T. Borowski and T. Wierzchoń

D.: Morphology and corrosion characteristics of laser surface remelted Al-Si alloy at cryogenic conditions. Materials and Corrosion 53 (2002), pp. 335-340. Serbiński W.: Tribologiczne warstwy powierzchniowe mangan-azot wytwarzane na stopach aluminium z krzemem. Inżynieria Materiałowa , vol. 27 (2006), pp. 532-535. Serbiński W.: Manganese-nitrogen-sulphur layers produced on aluminium alloys. Proc. 13th International Scientific Conference Achievements in Mechanical and Materials Engineering AMME 2005. Gliwice

Open access

H. Smoleńska

. Douglass and J. S. Armijo; The Influence of Manganese and Silicon on the Oxidation Behavior of Co-20Cr; Oxidation of Metals , Vol. 3, No. 2, 1971. D. E. Jones and J. Stringer; The Effect of Small Amounts of Silicon on the Oxidation of High-Purity Co-25 wt. % Cr at Elevated Temperatures Oxidation of Metals , Vol. 9, No. 5, 1975. P. Y. Hou* and J. Stringert; Effect of Internal Oxidation Pretreatments and Si Contamination on Oxide-Scale Growth and Spalling Oxidation of Metals , Vol 33, Nos. 5/6, 1990

Open access

A. Zieliński, W. Serbiński, B. Majkowska, M. Jażdżewska and I. Skalski

References Tang H. C., Cheng F. T., Man H. C.: Effect of surface melting on corrosion and cavitation erosion behaviors of manganese-nickel-aluminium bronze, Materials Science and Engineering A 373 (2004), 195 - 203. Serbiński W., Olive J. M., Rudnicki J.: Laser surface treatment of aluminium-silicon alloy at cryogenic conditions. Advances in Materials Science Vol. 3, nr 1(3), (2003), 51-59. Serbiński W., Zieliński A., Dziadoń A., Wierzchoń T.: Structural transformations in syrface

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Z. Ławrynowicz

(2007) 87-92. 5. Davis J.R. in “ASM speciality handbook”, (ed. J.R. Davis) (1996), 192-204 Metals Parks, OH, American Society for Metals. 6. Darwish N., Elliott R.: Austempering of low manganese ductile irons. Materials Science and Technology. 9 (1993) 572-585. 7. Elliott R.: The role of research in promoting austempered ductile iron. Heat Treatment of Metals. 23 (1997) 55-59. 8. ASTM standard A897M-90metric, ASTM, Philad. PA, USA, (1990) 560-565. 9. Soliman M., Palkowski H., Development of the low temperature bainite. Archives of Civil

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Ż. A. Mierzejewska

Achievements in Materials and Manufacturing Engineering, 29 (2008). 14. Ducki K.J., Cieśla M., Hetmańczyk M., Kuc D., Kamiński P.: The influence of increased nitrogen contents on structure and selected properties of tool steels. Proceedings of the 7th Scientific Conference “New Production Technology and Materials in Metallurgy and Materials Engineering”, Katowice (2000), 123-128 (In Polish). 15. Standard specification for wrought nitrogen strengthened 21 chromium-10 nickel- 3 manganese-2.5 molybdenum stainless steel alloy bar for surgical

Open access

A. Ziewiec, A. Zielińska-Lipiec, J. Kowalska and K. Ziewiec

–586. 15. Kowalska J., Ratuszek W., Chruściel K.: Crystallographic relations between deformation and annealing texture in austenitic steels. Archives of Metallurgy and Materials 53/1 (2008) 131–137. 16. Witkowska M., Zielińska-Lipiec A., Kowalska J., W. Ratuszek, Microstructural Changes in a High-Manganese Austenitic Fe-Mn-Al-C Steel, Archives of Metallurgy and Materials 59 (2014) 971–975. 17. Das C. R. et al: Weldability of 17-4PH stainless steel in overaged heat treated condition. Science and Technology of Welding and Joining 11 (2006) 502-508. 18