Modification Effects of La-Rich Mischmetal and Strontium Metal on A357 Alloy

Opting for desirable modifiers is an important way to obtain coast Al-Si-Mg alloys with both high strength and good toughness properties.Structures,mechanical properties and hydroden contents of as-cast and as-heattreated A357 alloy are investigated by comparing modification effections of lanthanum(La)-rich mischmetal and Strontium (Sr).It is shown from our experiments that modification effections of La-rich mischmetal is better than that of Sr as Fe content in the alloy is lower than 0.11% in the aspects of removal of hydrogen from the alloy,refinement of entectic silicons and improvement of mechanical properties,therefore,La-rich mischmetal is a desirable modifier for Al-Si-Mg alloy.     

Effect of Yttrium on Morphologies of Precipitation Phases Along Grain Boundary of As-cast ZK60 Magnesium Alloy

Morphologies of precipitation phases along grain boundary of the as-cast Mg-6.0Zn-0.45Zr, Mg-6.0Zn-(1.2Y) and Mg-6.0Zn-0.6Zr-1.0Y alloys are studied by using the methodologies of metallurgical phase analysis, scanning electron microscopy(SEM) analysis and energy diffraction x-ray(EDX) analysis. The experimental result indicates that the main precipitation phases along grain boundary of the as-cast alloys Mg-6.0Zn-0.45Zr is Mg-Zn binary phase. There are two kinds of precipitation phases along grain boundary for Mg-6.0Zn-1.2Y and Mg-6.0Zn-(0.6)Zr-1.0Y alloys. One grew at triangular grain boundary, which is fish-bone -like and contained Mg-Zn binary phase and Mg-Zn-Y ternary phase. The other distributed mainly around the grain, which is net-like and contained Mg-Zn-Y ternary phase. In addition, there are lots of granular phases, extending to the interior of the grain, at the rim of grain boundary phases. Finally, Y can intensively change morphology of precipitation phases along grain boundary of the as-cast Mg-Zn-Zr alloy (ZK60) alloys.     

Development of CuMn35 Master Alloy

This article has investigated the principle and method of smelting CuMn35 master alloy by fusion alloying. And some questions about deoxidation and removal of hydrogen has been discussed. We have found the best process conditions after a series of orthogonal experiments and obtained uniform components by chilling technique. Elsewhere, we use carbon and cryolite as covering agent and refining agent to reduce oxide inclusion greatly and improve the surface texture and the yield of copper and manganese, attained 99.99% and 99.31% respectively. The results of the experiment show that the process is advisable.     

Structure Refining Effect of Die Casting on the Hypoeutectic Al-11Si-1.8Cu Alloy

On the basis of different casting conditions such as normal gravity casting and high pressure die casting, the structure refining effect of die casting on the hypoeutectic Al-11Si-1.8Cu alloy is investigated by structure analysis. The research results indicate that compared with normal gravity casting, die casting can obviously refine the primary a-Al and eutectic Si phase of Al-11Si-1.8Cu alloy, and the morphology of primary a-Al changed from dendrite shape to spherical shape. Furthermore, under the condition of high pressure die casting, with the casting pressure increasing, the spherical morphology and size of primary a-Al are more round and small respectively, and the precipitaion of eutectic Si phase is suppressed simultaneously.     

Calculating the proportion of Nd-rich phase in NdFeB alloy via Matlab software

Nd-rich phase plays an important role in the magnetic properties of sintered NdFeB alloy. The proportion of Nd-rich phase to all the other phases was calculated by using MATLAB 6.5 software. Especially, post-sintered alloy, post-high-temperature tempered alloy and post-high and low-temperature tempered alloy were analyzed. It was found that the proportion of Nd-rich phase in the three alloys based on SEM (scanning electron microscope) images was about 8.22%, 8.03% and 8.00%, respectively.     

Modeling of Liquidus Temperature for Al-Si Cast Alloys with Adaptive Neuro-fuzzy Inference System

During the melting and processing practices, an accurate knowledge of liquidus temperature is necessary in the determination of process parameters relating to a given alloy. Adaptive neuro-fuzzy inference system (ANFIS) modeling method has been used to improve accuracy of prediction for liquidus temperature based on the compositions of Al-Si series cast alloys. The developed fuzzy inference system could extract Takagi-Sugeno type fuzzy rules from data directly, and has a feed-forward network structure with supervised learning capability. In order to adapt the parameters of the model, the proposed fuzzy inference system is trained over a wide range of compositions from the published data of industrial alloys. The result shows that, the developed ANFIS model can capture non-linear relationships between compositions and liquidus temperature, and then provides better prediction than the reported multiple statistic analysis. The developed model can be used to predict the liquidus temperature needed in computer modeling and thermodynamic calculation, which are needed in the aluminium alloys casting industry and research.     

Effect of Chemical Composition on Formation Performance of 7050 Alloy Billets

The casting technology of 7050 alloy bilits is researched. that are used to produce slabs for air materials.Because the composition of 7050 alloy is very complex,the Cu and Zn elements contents are higher and Fe and Si impurity elements contents are controlled lower, at the same time ,the specification and the width-thickness ratio are large ,all of above result the tremendous crack trend when casting and bad casting formation performance . The formation performance of 7050 alloy has been improved and qualified billits are obtained by optimizing the composition of 7050 alloy, including raising Fe/Si ratio and Zn/Mg ratio ,reducing Cu content and adopting the joint refinement with block and silk shaped Al-5Ti-1B.     

Review on the Research of High-strength Wrought Magnesium Alloy ZK60

ZK60 magnesium alloy is one of high-strength wrought magnesium alloys. Owing to its high strength and low density, it has nearly the highest strength to density ratio among existing materials. Because its strength approximates to high-strength aluminum alloy 7075, it has promising application future. The history of magnesium alloy ZK60 and researches on its microstructure, mechanical properties, surface treatment, and the effects of alloy elements and microelements are reviewed . Further more, the authors put forward methods to improve its microstructure and mechanical properties and prospected the development future of this alloy in the aspects of surface treatment and application.     

Research Status and Development of AZ31 Magnesium Alloy

The characters of AZ31 Magnesium Alloy are reviewed. The effects of main alloying elements on microstructures and properties, mechanical properties, grain refinement and superplasticity of AZ31 magnesium alloy are discussed. Future development directions and application areas are also introduced, noting that new forming technology magnesiumbased composites and the basis theory of AZ31 Magnesium Alloy should be future research emphases.     

Inter-relationships Amongst Grain Characteristics, Grain-Filling Parameters and Rice (Oryza sativa L.) Milling Quality

Resistance to breakage is a desirable trait of the rice kernel. Many factors, such as the genetics of the cultivar, the plant growth environment and the conditions of the milling process, will affect kernel breakage. Although many papers have discussed the factors that may affect and improve rice milling quality, few have related the grain-filling process to head rice, the unbroken polished kernels obtained after milling. The objectives of this paper were: (i) to characterize the interrelationships amongst grain filling and grain structural characteristics; (ii) to determine whether the grain-filling process and grain characteristics affect head rice, and (iii) to suggest a pathway through which grain characteristics can influence head rice recovery. An analysis of the interrelationships amongst all grain characteristics suggested that variables of grain structure (size, volume and per cent hull) have a decisive influence on the grain-filling process (rate and duration of grain filling). The grain-filling process will affect final grain traits such as weight and density, which in turn will have a direct impact on head rice. In addition, non-uniformity, whether expressed in terms of variable grain size and shape or grain filling and maturity, has a detrimental effect on rice milling quality. The implication of these findings is that rice breeders need to pay more attention to selecting plant types that have a high degree of uniformity of grain characteristics on the panicle, and to those traits (such as greater grain size, weight and density) that have a positive impact on yield and milling quality.     

Smelting AlMnSi alloy by Using High-bearing Manganese Slag

First smelting MnSi alloy by using high-bearing manganese slag of BF by electric smelting process in a 25 kVA arc furnace in lab has been introduced. In order to increase the content of manganese and silicon in MnSi alloy , a little amount of MgO is added into the slag and the lower alkalinity has been adapted. Then smelting AlMnSi alloy using MnSi alloy containing high silicon that obtained by experiments and waste Al with an induction furnace has been studied. The controlling of temperature is the key in smelting process. The high quality AlMnSi alloy has been obtained successfully,Which can be extensively used for the compound oxygen removal agent for making steel and the metal alloy additive.     

Nitration Process and Structural Analysis on MnN

The production theory and the production process of MnN by solid-nitration process with manganese power is introduced. In order to obtain MnN, manganese power has been nitrided by pure nitrogen at high temperature in pipe-type-oven at lab. Suitable nitration technical parameters, such as manganese power size, nitriding temperature and nitriding time have been gotten by a series of experiments. MnN production that nitrogen content is 6.94% has been obtained. In addition, three alloys composed manganese nitrogen (Mn_(3)N_(2), Mn_(2)N,Mn_(4)N) have been obtained and their distributions are observed by the way of XRD and SEM.     

Effect of phytic acid modification AZ31 magnesium alloy on the cell surface adhesion property

Phytic acid coatings on the surface of AZ31 magnesium alloys are prepared by immersion method. Then cell culture and detection of cell survival rate on treated or untreated AZ31 magnesium alloy with phytic acid is carried out by the direct method and the indirect method respectively,and surface morphology and chemical composition of coatings are studied by scanning electron microscopy with energy dispersive spectrometer. The results show that uniform phytic acid coating forms on the surface of magnesium alloy,and there is a similar cell survival rate on the treated or untreated AZ31 magnesium alloy surface. But the adhesive ability of cells on the surface of phytic acid modification magnesium alloy is significantly different. Phytic acid modification can effectively improve the cell adhesion properties of AZ31 magnesium alloy.     

选区激光熔化TC4生物腐蚀和生物相容性分析

选区激光熔化(SLM)为降低TC4钛合金医用植入体的弹性模量、减小应力屏蔽效应提供了一种有效的解决方案,但这种材料在投入实际应用前尚需有充分的生物安全性评价。采用SLM技术制备出致密度为99.5%的TC4合金,通过电化学实验、溶血实验和细胞毒性实验测试了SLM成形TC4的生物腐蚀性能和生物相容性,并与传统铸轧工艺制备的合金进行了对比。实验结果表明：前者相比于后者有着更好的耐蚀性能,并且SLM成形TC4还具有优良的生物相容性,在生物医用植入物方面展现出很好的应用前景。     

中子辐照对锆合金显微组织的影响研究进展

作为反应堆的第一道安全屏障,锆合金包壳材料的显微组织一直是国内外的研究热点。针对目前国内外在中子辐照对锆合金显微组织的影响研究领域现状进行了综述,总结了现有研究的不足并提出了对未来研究方向的建议：采用微观分析手段,针对不同中子注量下锆合金包壳的第二相、氢化物和氧化膜展开研究,获得其在实际使用工况下的演变规律,为我国锆合金包壳材料的优化改进提供支撑。     

Optimization of a web based query system for a magnesium alloy database

Based on an existing magnesium alloy database, a query system is optimized by considering the design characteristics, and an integrated query system for this magnesium alloy database is developed to meet the demands of more users. The result shows that the new system improves the query efficiency of the magnesium alloy database, especially for queries concerning phase diagrams and the structure of magnesium alloys. This means that the new system provides users a more powerful and useful magnesium alloy database.     

Effect of selection for pollen grain size on various traits in common bean

Summary Selection among microgametophytes usually exploits variation in pollen grain germination. Studies of variation in pollen grain size in common bean (Phaseolus vulgaris L.) suggested that selection for size might lead to changes in sporophytic traits. To determine whether microgametophytic selection based on size would affect pollen grain size in subsequent generations or sporophytic traits that were correlated with pollen grain size, pollen grains from three crosses were separated into two size categories by sieving and then used to pollinate cv. Diacol Calima. Selection resulted in changes in pollen grain diameter for pollen from F₁, F₂ and F₃ plants for all crosses. In vitro germination indicated no differences between vigor of large and small grains, but extraction and sieving reduced germinability. F₁ seed from two of the crosses with size-selected pollen varied in weight according to pollen grain size, but in subsequent generations, the effect disappeared. Both size categories of selected pollen resulted in F₂ progeny with reduced numbers of seeds per pod as compared to controls, suggesting that the size selection process may have resulted in indirect selection for traits reducing seed set. The overall results suggested that genes determining pollen grain size in bean have little or no effect on sporophytic traits such as seed size and seed yield.     

Formation of Zinc Oxide in the Course of Directed Nitriding With Aluminum Zinc Alloy

ZnO is formed in the course of directed nitriding with Al-Zn alloy, and that the effect of zinc and magnesium on the directed nitriding process is big different. The long fibers which diameter are far less than one micrometer, short bar-like and tetrapod-like zinc oxide is obtained. The three important stages of initial growth kinetic of ZnO approving ZnO have growth mechanism of VS, they are stage of accelerating, linear and parabola, are discovered. Experimental results show that the volatilization of zinc play a very important role in the growth of ZnO,the growth of ZnO is controlled by the diffusion of zinc in the Al-Zn alloy , and the morphologies of ZnO is depend on the saturation level of the vapour.     

COMPUTER IZED SIMULATION OF SPINODAL DECOMPOSITION IN Fe-Cr ALLOYS

The kinetic process of spinodal decomposition in Fe-Cr alloys has been simulated with the aid of the compuler M340. The uphill diffosion of Fe-Cr alloy during spinodal decomposition has been investigated in atomic scale with Monte Carlo method. The computer simulated diagram is in agreement with the experimentally measured one.