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S. Buyukakkas H. Aktas S. Akturk 《北京科技大学学报(英文版)》2007,14(4):327-330
The effect of austenitization heat treatment on magnetic properties was examined by means of M6ssbauer spectroscopy on an Fe-40wt%Ni-2wt%Mn alloy. The morphology of the alloy was obtained by using scanning electron microscopy (SEM) under different heat treatment conditions. The magnetic behavior of the non heat-treated alloy is ferromagnetic. A mixed magnetic structure including both paramagnetic and ferromagnetic states was obtained at 800℃ after 6 and 12 h heat treatments. In addition, the magnetic structure of the heat-treated alloy at 1150~C for 12 h was ferromagnetic. With the volume fraction changing, the effective hyperfine field of the ferromagnetic austenite phase and isomery shift values were also determined by Mtssbauer spectroscopy. 相似文献
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Crystallographically oriented etch traces produced by selective etchant on (111) and (110) habit faces of dicalcium strontium
propionate [Ca2Sr(C2H5CO2)6] crystals are attributed to the growth traces nucleated during the superficial growth of crystal. This view is supported
by the absence of such etch traces on seized habit faces and from the observations of layer structure on the bottom faces.
Mother liquid acting as an etchant produces circular terraced depressions on habit faces. These depressions originate at the
sites of isolated impurity centres. Identical features such as circular etch structures bounded by cylindrical outer periphery
produced on cooled faces are attributed to isolated domains. 相似文献
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本文针对ZL109合金圆柱体铸件,在砂型铸造条件下,研究了凝固时间τ,温度梯度G,凝固指数fi,真温度梯度加速度GAP与铸件二次枝晶间距DAS,孔洞率戶和极限抗拉强度UTS之间的关系。结果表明:1.τ,fi与DAS的关系最为密切。2.DAS和户都影响铸件的UTS,在本实验条件下,DAS的影响是主要的,P可忽略不计,可以用DAS来评定UTS。3.fi与UTS的关系最为密切,用fi来控制UTS更为有效。此外,还探讨了铸件由表及里DAS的变化及用DAS无损测试铸件UTS的精度。 相似文献
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模具钢的激光熔覆组织和性能 总被引:1,自引:0,他引:1
利用不同的激光工艺参数对Cr12MoV模具钢表面进行熔覆试验,探讨了工艺参数对熔覆层深度的影响,研究了表面微观硬度的趋势及其原因、熔覆层耐磨性能的提高幅度以及组织结构的变化。结果表明:表面硬度在不同程度上都得到提高,硬度峰值出现在次表层;激光熔覆层的耐磨性能可以提高到1.91-4.24倍;微观结构由平面晶和枝晶构成的共晶组织,并有多种合金相分布在枝晶间。 相似文献
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抽象出了两种简单的枝品形态,通过对凝固过程中固液界面传质过程的分析,对Flemings的“局部溶质再分配方程”进行了修正。考虑了固相中的扩散,提出了更为一般的局部济质再分配方程。结合具体的凝固过程,选择恰当的参数,该方程可用于宏观偏析和微观偏析的计算及非平衡凝固条件下第二相和非平衡共晶析出量的估算。 相似文献
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