Development of a lock-on type laser spot heating system and its application to coding and de-coding technology of microstructural information

锁定式激光点加热系统的研制及其在微结构信息编解码技术中的应用

基本信息

批准号：
17360353
负责人：
TSUKAMOTO Masahiro
金额：
$ 10.34万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

项目摘要

The present project aims to newly develop a laser spot heating system which can produce peculiar microstructure in polycrystalline materials. This project comprises three missions such as 1) computer simulation of grain growth, 2) design and construction of laser heating system, and 3) spot heating experiments on pure aluminum and titanium utilizing the laser heating system. Prior to the experimental work, a Monte Carlo simulation method was adopted to simulate grain growth process starting from initial grain structure with bimodal grain size distribution. The simulation clearly showed that a preferential growth of grains having twice larger size than surrounding grains took place, suggesting the spot heating would create quite new microstructure when it is practically realized. The present heating system enables a collimated laser beam focus on specimen surface with a diameter less than 10 μm. Effectiveness of the present spot heating method is verified as follows. The spot heating yielded a cluster composed of recrystallized grains in the deformed matrix. Size of the cluster is around 160μm and this artificial microstructure has never been reported so far. The spot heating system can lock-on any target areas to be heated, and five-spot heating was performed to show five clusters having grains with different orientations. Texture control is also expected to be realized by the present heating system. These new findings strongly suggest that the spot heating method with a heating area comparative to the size of microstructure parameters such as grains, second phase, particles and even dense dislocation walls will enables us to fabricate peculiar microstructures that we design.

本项目旨在新开发一个激光斑点加热系统，该系统可以在多晶材料中产生特殊的微结构。该项目包括三个任务，例如1）谷物生长的计算机模拟，2）激光加热系统的设计和构建，以及3）使用激光加热系统对纯铝和钛进行的斑点加热实验。在实验工作之前，采用了一种蒙特卡洛模拟方法来模拟晶粒生长过程，从具有双峰晶粒尺寸分布的初始谷物结构开始。该模拟清楚地表明，具有比周围谷物大两倍的谷物的首选生长，这表明斑点加热将在实际实现时会产生相当新的微观结构。目前的加热系统使对直径小于10μm的样品表面上有效的激光束。当前斑点加热方法的有效性如下验证。斑点加热产生了一个由变形基质中的重结晶晶粒组成的簇。簇的大小约为160μm，到目前为止，这种人工微观结构尚未报道。斑点加热系统可以锁定要加热的任何目标区域，并进行五个斑点加热以显示五个具有不同方向的谷物的簇。预计纹理控制也将通过当前的加热系统实现。这些新发现强烈表明，具有加热区域的斑点加热方法与微观结构参数的大小（例如晶粒，第二相，颗粒，甚至密集的脱位壁）进行了比较，这将使我们能够制造我们设计的特殊微观结构。