粗晶粒的

Moreover,Al_2Er phase is face centered cubic structure,which is different with the structure of Mg(Hexagonal Close-Packed).

但是过量的Zr将与合金中的Al反应生成Al_3Zr沉淀相，消耗了合金中的Al元素，减弱了Al对镁合金的细化、强化作用，而且由于Al_3Zr与镁基体没有共格关系，不能起到细化晶粒的作用，合金组织粗化。

The modification of the Gladman's model may then be proposed by the comparison of different models of grain coarsening with assumption of uneven in convexo-concave interface along grains. The modified Gladman's expression is given as: R_o =πr/3f_v(3/-2/Z) that may fairly predict the actual grain size observed.

比较了已有的晶粒粗化模型，在晶界面为凸凹不平的曲面前提下，对Gladman模型做了修正，提出了如下的修正Gladman公式： R_0=πr/3f_v(3/2-2/Z)该公式能较好地预测晶粒的实际尺寸。

The improved model not only describes grain growth,but also describes coarsening of dendrite arms.

模型除了描述了晶粒的生长，同时还描述了枝晶臂的粗化。

The grain boundary structure in these nanostructured materials is similar to that of the conventional coarse grained materials.

在这些纳米结构材料中的晶粒边界结构与传统的粗晶粒材料的结构相似。

For example,nanostructured ceramics are tougher and stronger than the coarser grained ceramics .

例如，纳米结构陶瓷比粗晶粒陶瓷有较好的韧性和较高的强度。

With the increasing of undercooling, the mean crystal diameter of supercooled solidification microstructures shows a variation from coarse to fine, then fine to coarse, and finally fine again. The coarse crystals are developed crystals, while the fine crystals are spherical crystals with a mean diameter about 50μm.

2随着过冷度的增加，深过冷凝固的微观组织的晶粒直径呈现出"粗—细—粗—细"的变化规律，粗晶为发达的等轴枝晶，细晶则为直径约50μm的球晶。

According to different assession theories, different experimental results can be given possible explanations

在较粗的晶粒范围内，大晶粒的氧化铝陶瓷具有较好的抗热震性，而在较细的晶粒范围内，小晶粒的氧化铝陶瓷具有较好的抗热震性

The relatively low finishing temperature can lead to the coarsened grain...

终轧温度的降低可引起奥氏体晶粒的粗化和残余应变的显著提高。

The results showed that for both of the alloys grains were obviously refined to same extent with increase in Ti content, and the grain sizes were coarsened to some extent due to evident fading of Ti effect during melt holding period....

随着保温时间的延长，所有合金的晶粒尺寸均不同程度发生了粗化，Ti对晶粒的细化效果明显发生了衰退。电解加钛铝合金晶粒细化效果的抗衰退能力优于熔配加钛铝合金，这种趋势对Ti的质量分数为 0 。1%～ 0 。2 %的合金特别明显。

The experimental results show that microwave sintering promotes the densification of green compacts with higher heating rate and reduced sintering cycle. The sintered relative density of 99.8% can be achieved during microwave processing under appropriate conditions. In addition, microwave sintering improves the uniformity and homogenization of W grain size, and yet leads to growth of W grain. Fe sintering aid degrades the microstructure uniformity and further coarsens W grains. The present investigation demonstrates the feasibility of applying microwave sintering technique to consolidate W-Cu composites and its promising outlook in reducing production cycle and cost.

结果表明：微波烧结升温速度快，周期短，能促进W-Cu材料的致密化；在适当条件下，微波烧结能获得相对密度达99.8%的W-Cu样品；微波烧结能改善W-Cu样品中两相分布的均匀性和W晶粒尺寸的一致性，但引起W晶粒的快速长大；Fe烧结助剂导致W-Cu材料显微组织均匀性变差，并引起晶粒进一步粗化；微波烧结技术能够应用于W-Cu材料的制备，在缩短生产周期、降低生产成本方面具有潜在优势。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐