Effect of Manganese Addition on Strength and Fracture Toughness in Mg-6Al-1Zn Alloy

2006 ◽  
Vol 306-308 ◽  
pp. 857-862 ◽  
Author(s):  
Taisuke Sasaki ◽  
Tokuteru Uesugi ◽  
Yorinobu Takigawa ◽  
Kenji Higashi

The effect of manganese on strength and fracture toughness was investigated using five kinds of Mg-6Al-1Zn alloys. From the experimental results, the yield strength increased with increasing in manganese content until manganese content reached 0.14 wt. %. On the other hand, further increase in yield strength was not observed in case larger than 0.14 % of manganese was added. In addition, fracture toughness decreases with increasing manganese content. Fracture of magnesium alloy was ductile fracture by void coalescence. Adding excessive amount of manganese caused the increase in the presence of inclusions. This kind of particle easily became the nucleus of microvoid. As a conclusion, manganese should be added so that coarse manganese-bearing particle is not formed. Thus, 0.14 wt. % of manganese should be added to Mg-6Al-1Zn alloy in order to develop the alloy with well-balanced relationship between strength and fracture toughness.

Alloy Digest ◽  
1977 ◽  
Vol 26 (2) ◽  

Abstract SAF 1039 steel can be used in the hot-rolled, normalized, oil-quenched-and-tempered or water-quenched-and-tempered condition for general-purpose construction and engineering. Its manganese content is a little higher than some of the other standard carbon steels with comparable carbon levels; this gives it slightly higher hardenability and hardness. It provides medium strength and toughness at low cost. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: CS-66. Producer or source: Carbon steel mills.


1948 ◽  
Vol 21 (4) ◽  
pp. 853-859
Author(s):  
R. F. A. Altman

Abstract As numerous investigators have shown, some of the nonrubber components of Hevea latex have a decided accelerating action on the process of vulcanization. A survey of the literature on this subject points to the validity of certain general facts. 1. Among the nonrubber components of latex which have been investigated, certain nitrogenous bases appear to be most important for accelerating the rate of vulcanization. 2. These nitrogen bases apparently occur partly naturally in fresh latex, and partly as the result of putrefaction, heating, and other decomposition processes. 3. The nitrogen bases naturally present in fresh latex at later stages have been identified by Altman to be trigonelline, stachhydrine, betonicine, choline, methylamine, trimethylamine, and ammonia. These bases are markedly active in vulcanization, as will be seen in the section on experimental results. 4. The nitrogenous substances formed by the decomposition processes have only partly been identified, on the one hand as tetra- and pentamethylene diamine and some amino acids, on the other hand as alkaloids, proline, diamino acids, etc. 5. It has been generally accepted that these nitrogenous substances are derived from the proteins of the latex. 6. Decomposition appears to be connected with the formation of a considerable amount of acids. 7. The production of volatile nitrogen bases as a rule accompanies the decomposition processes. These volatile products have not been identified. 8. The active nitrogen bases, either already formed or derived from complex nitrogenous substances, seem to be soluble in water but only slightly soluble in acetone.


Author(s):  
H. van Nooy

AbstractThe experimental results indicated in the present paper reveal that among all humectants admitted 1,3-butyleneglycol alone has marked fungicidal properties satisfying the requirements of practical tobacco treatment, and that, on the other hand, diethyleneglycol and glycerine practically do not have such qualities


2018 ◽  
Vol 19 (10) ◽  
pp. 3045 ◽  
Author(s):  
Takehito Kikuchi ◽  
Yusuke Kobayashi ◽  
Mika Kawai ◽  
Tetsu Mitsumata

Magnetorheological elastomers (MREs) are stimulus-responsive soft materials that consist of polymeric matrices and magnetic particles. In this study, large-strain response of MREs with 5 vol % of carbonyl iron (CI) particles is experimentally characterized for two different conditions: (1) shear deformation in a uniform magnetic field; and (2), compression in a heterogeneous uniaxial magnetic field. For condition (1), dynamic viscoelastic measurements were performed using a rheometer with a rotor disc and an electric magnet that generated a uniform magnetic field on disc-like material samples. For condition (2), on the other hand, three permanent magnets with different surface flux densities were used to generate a heterogeneous uniaxial magnetic field under cylindrical material samples. The experimental results were mathematically modeled, and the relationship between them was investigated. We also used finite-element method (FEM) software to estimate the uniaxial distributions of the magnetic field in the analyzed MREs for condition (2), and developed mathematical models to describe these phenomena. By using these practicable techniques, we established a simple macroscale model of the elastic properties of MREs under simple compression. We estimated the elastic properties of MREs in the small-strain regime (neo–Hookean model) and in the large-strain regime (Mooney–Rivlin model). The small-strain model explains the experimental results for strains under 5%. On the other hand, the large-strain model explains the experimental results for strains above 10%.


2008 ◽  
Vol 14 (4) ◽  
pp. 307-313 ◽  
Author(s):  
F. Beltrán ◽  
A.J. Perez-López ◽  
J.M. López-Nicolás ◽  
A.A. Carbonell-Barrachina

Eight mandarin cultivars have been analyzed for their content of vitamin C, minerals (Ca, Mg, K, Na, Fe, Cu, Mn, and Zn), CIELab color coordinates (L*, a*, b*, C*, and h ab), total volatile compounds content and sensory aroma intensity of juice. Experimental results proved that no important enough differences were found in the minerals contents to decide which mandarin cultivar was of higher quality. Clemenules provided the darkest juice with the highest vitamin C content and with the most intense mandarin aroma. On the other hand, Nova and Hernandina mandarin could be considered as the worst cultivars for juice production. Finally if Clemenules mandarins were not available for juice processing, Orogrande, Clemenpons, Ellendale, and Marisol could also be good options.


Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 352 ◽  
Author(s):  
Kairui Cao ◽  
Rui Li

Hysteresis is a kind of nonlinearity with memory, which is usually unwanted in practice. Many phenomenological models have been proposed to describe the observed hysteresis. For instance, the Prandtl-Ishlinskii (PI) model, which consists of several backlash operators, is the most widely used. On the other hand, the well-known Madelung’s rules are always used to validate hysteresis models. It is worth pointing out that the PI model obeys Madelung’s rules. In this paper, instead of considering these rules as criteria, we propose a modeling method for symmetric hysteresis by directly constructing the trajectory based on Madelung’s rules. In the proposed method, turning points are recorded and wiped out according to the input value. After the implementation of the recording and wiping-out mechanisms, the curve which the current trajectory moves along can be determined and then the trajectory can be described. Furthermore, the relationship between the proposed method and the PI model is also investigated. The effectiveness of the presented method is validated by simulation and experimental results.


Author(s):  
Teruki Sadasue ◽  
Satoshi Igi ◽  
Kenji Oi ◽  
Satoru Yabumoto

The reel-lay method is a fast and cost efficient installation process for offshore rigid steel pipelines. Pipelines installed by the reel-lay method are plastically deformed due to reeling, unreeling, aligning and straightening during pipeline installation. Therefore, local buckling is one of the major concerns from a view point of integrity in linepipes, especially around girth welds where strength mismatching arises due to adjacent pipes with different yield strength. One the other hand, the change in mechanical properties of linepipes during reel-lay, including coating process (e.g. 250°C) and long time exposure (e.g. 250°C aging) after installation is also important in order to guarantee safety of linepipes. Furthermore fracture toughness at girth weld Coarse-grain HAZ (CGHAZ) after reeling and aging should be clear to prevent brittle fracture of offshore linepipes in service. In this study, full scale reeling simulation tests of girth welded X60 HFW (High Frequency electric resistance Welded) linepipes with OD; 323.9mm and WT;15.9mm after full body heat treatment (coating simulation) were conducted at 5cycles and 2cycles reeling and straightening situations when yield strength mismatches are present between adjacent pipes around girth welds. Localized strain concentration was observed near girth welds by strength mismatching of adjacent pipes. DNV ovality increased with increasing reeling and straightening cycles, however the ovality did not exceed 10%, which was a criterion value for local buckling, after 5cycles reeling simulation test. The change ratio of wall thickness after full scale reeling simulation tests were about ±2% (within DNV-OS-F101 tolerance) regardless of circumferential and longitudinal direction of pipes. Longitudinal tensile properties could be characterized by axial last introduced plastic strain. That is, in the positive number of last introduced plastic strain, YS and Y/T increased, while uEl decreased by work hardening effect. On the other hand YS and Y/T decreased, while uEl increased at the negative number of last introduced plastic strain by Bauschinger effect. Circumferential tensile properties could be also characterized by axial last introduced plastic strain. Yield strength and Y/T slightly increased while uniform elongation slightly decreased by aging at longitudinal and circumferential direction. Tensile properties did not change irrespective of the number of cycles of reeling simulation tests. After 5cycles reeling simulation test and aging, girth welded CGHAZ CTOD values were over 0.4mm at −20°C and Charpy absorbed energy were over 200J at −30°V, therefore, it was considered that the brittle fracture of the girth welded linepipe unlikely occur at reeling and aging situation in this study.


1964 ◽  
Vol 19 (6) ◽  
pp. 747-755
Author(s):  
W. J. De Wet ◽  
J. Los

The design of mass diffusion columns operated with partition membranes, for the separation of light gaseous isotopes, is discussed. A theoretical analysis of experimental results obtained indicates that a good agreement between experimental results and theory is only obtained at low column pressures and moderate countercurrent flow rates. At fairly low countercurrent flow rates mixing effects due to viscous dragging and gas solubility by the condensate appear to be considerable whereas excessively high countercurrent flow rates, on the other hand, also seem undesirable. Some suggestions are proposed to obviate impairing effects at least to some extent.


Algorithms ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 14
Author(s):  
Jianjian Ji ◽  
Gang Yang

Existing image completion methods are mostly based on missing regions that are small or located in the middle of the images. When regions to be completed are large or near the edge of the images, due to the lack of context information, the completion results tend to be blurred or distorted, and there will be a large blank area in the final results. In addition, the unstable training of the generative adversarial network is also prone to cause pseudo-color in the completion results. Aiming at the two above-mentioned problems, a method of image completion with large or edge-missing areas is proposed; also, the network structures have been improved. On the one hand, it overcomes the problem of lacking context information, which thereby ensures the reality of generated texture details; on the other hand, it suppresses the generation of pseudo-color, which guarantees the consistency of the whole image both in vision and content. The experimental results show that the proposed method achieves better completion results in completing large or edge-missing areas.


2006 ◽  
Vol 326-328 ◽  
pp. 685-688
Author(s):  
Hyung Ick Kim ◽  
Yong Huh ◽  
Jeong Pyo Kim ◽  
Chang Sung Seok

The mechanical properties of in-service facilities under harsh environment a decrease as materials of the facilities degrade. This decrease of mechanical properties can affect the safety operation of the facilities. Therefore, the extent of degradation due to prolonged service exposure must be estimated. Nondestructive evaluation method is a good technique for monitoring the change of mechanical properties of in-service facilities. The most widely used nondestructive methods are the ultrasonic method and the indentation test, which is advantageous with respect of applicability to in-service facilities. The modified theoretical Vary's equation, considering nonlinear response due to material degradation, was proposed for obtaining the correlations between ultrasonic parameters and fracture toughness. Experimental results showed that ultrasonic attenuation, velocity, and nonlinear parameters have significant correlation with fracture toughness and yield strength. The nondestructive evaluation system can be used to obtain the yield strength and ultrasonic parameters simultaneously, and this information can be used to predict the fracture toughness. The predicted results produced good correlations with the experimental results, indicating that the nondestructive evaluation system can be effective in evaluating material properties and degradation, and the life time of facilities.


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