The paper analyzes the effect of substrate temperature on the shape, size, and orientation of grains in the structure of VT6 alloy samples formed by the method of direct laser deposition of powder. It was established that in the samples of titanium VT6 powder alloy, the following three characteristic structural zones are formed: a fine equiaxed grain zone, an oriented columnar grain zone, and a zone combining both types of grains. By preheating the substrate prior to sample growing, it became possible to reduce the length of the equiaxed grain zone, while increasing the width of the columnar grains. Cooling the substrate during the sample growing process made it possible to solidify metal from a heterophase state, which allowed preserving the structure of the initial powder. A method for preheating the substrate prior to sample growing and force-cooling it after applying the first several layers of powder is proposed. The new method made it possible to reduce the length of the equiaxed grain zone and increase the length of the columnar grain zone in the metal structure of the samples formed by direct laser deposition method.

中文翻译：

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直接激光沉积过程中衬底温度对钛合金组织形成的影响

本文分析了基体温度对粉末直接激光沉积法形成的VT6合金样品组织中晶粒形状、尺寸和取向的影响。确定在钛VT6粉末合金样品中，形成了以下三个特征结构区：细等轴晶区、定向柱状晶区和两种晶粒相结合的区。通过在样品生长之前预热基板，可以减少等轴晶粒区的长度，同时增加柱状晶粒的宽度。在样品生长过程中冷却基板可以使金属从异相状态固化，从而可以保留初始粉末的结构。提出了一种在样品生长之前预热基板并在施加前几层粉末后对其进行强制冷却的方法。新方法使得在直接激光沉积法形成的样品的金属组织中减小等轴晶区的长度和增加柱状晶区的长度成为可能。