元素添加方式对激光熔覆沉积Ti-25V-15Cr成形性的影响

Effect of Element Addition Method on Formability and Microstructure of Laser Cladding Deposited Ti-25V-15Cr Alloy

目的以阻燃钛合金Ti-25V-15Cr为研究对象,主要研究V、Cr元素粉末的添加方式对激光熔覆沉积Ti-25V-15Cr合金的显微组织及成形性的影响。方法分别以经过粘结包覆Ti(150mm)+V(15mm)+Cr(15mm)、直接混合Ti(150mm)+V(15mm)+Cr(15mm)以及直接混合Ti(150mm)+V(100mm)+Cr(150mm)的元素混合粉末为原料,进行激光熔覆沉积实验,对沉积试样的高度、宽度以及显微组织特征进行研究。结果以粘结包覆Ti(150mm)+V(15mm)+Cr(15mm)和直接混合Ti(150mm)+V(100mm)+Cr(150mm)为原料获得的沉积试样,其沉积效率显著高于直接混合Ti(150mm)+V(15mm)+Cr(15mm)为原料的沉积试样,且沉积试样组织由相对细小的等轴晶和类等轴晶组成,而直接混合Ti(150mm)+V(15mm)+Cr(15mm)为原料的试样组织主要由外延生长的柱状晶组成。结论以粘结包覆Ti(150mm)+V(15mm)+Cr(15mm)为原材料时,在提高沉积效率的同时能够一定程度上细化晶粒。该方法对激光熔覆沉积材料的成形性、成分均匀性及显微组织具有显著影响。

The work aims to investigate the effect of the addition method of elemental powders V and Cr on the microstructure and formability of laser cladding deposited Ti-25 V-15 Cr alloy with Ti-25V-15 Cr alloy as research subject. The deposition experiments were performed from three kinds of powder feedstock, including bonded coated Ti(150 mm)+V(15 mm)+Cr(15 mm),directly mixed Ti(150 mm)+V(15 mm)+Cr(15 mm) and directly mixed Ti(150 mm)+V(100 mm)+Cr(150 mm), and the height,width and microstructure of the deposited samples were analyzed. Deposited efficiency of the samples from the bonded coated Ti(150 mm)+V(15 mm)+Cr(15 mm) and directly mixed Ti(150 mm)+V(100 mm)+Cr(150 mm) were much higher than that from the directly mixed Ti(150 mm)+V(15 mm)+Cr(15 mm). The microstructure of the deposited samples from Ti(150 mm)+V(15mm)+Cr(15 mm) and from directly mixed Ti(150 mm)+V(100 mm)+Cr(150 mm) were mainly composed of fine equiaxed grains and near-equiaxed grains, while that from the directly mixed Ti(150 mm)+V(15 mm)+Cr(15 mm) consisted of epitaxially columnar grains. When the bonded coated Ti(150 μm)+ V(15 μm)+ Cr(15 μm) is used as the deposited material, the grain size can be refined to some extent while the deposition efficiency can be improved. This method has a significant influence on the formability, composition uniformity and microstructure of the laser cladding deposited samples.