Effect of grain size on the tensile ductility and fracture mechanism of Ti?O alloys
Effect of grain size on the tensile ductility and fracture mechanism of Ti?O alloys
复制标题
晶粒尺寸对Ti?O合金拉伸塑性和断裂机制的影响
DOI：
10.1016/j.msea.2023.145068
复制
发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Kondoh Katsuyoshi
中科院分区：
文献类型：
--
作者：
Kariya Shota;Issariyapat Ammarueda;Bahador Abdollah;Umeda Junko;Shen Jianghua;Kondoh Katsuyoshi
最近的几项研究报道了Ti-O合金的高延展性，这被认为是脆性的，但解释延展性的机制尚未阐明。本研究着重于晶粒尺寸与塑性之间的关系，以阐明Ti-O合金的高塑性的机制，发现塑性随着晶粒尺寸的增加而降低。Ti-0.77wt%O烧结合金的挤出物在晶粒尺寸达49.8 μm时表现出良好的延展性（>5%），但当晶粒尺寸超过98.4 μm时，合金在弹性区失效。在这些韧性细晶Ti-O合金的断裂区域中的晶界处观察到与晶粒尺寸相似的尺寸的裂纹。细晶Ti-O合金的变形行为的原位观察表明，由于裂纹细化引起的应力强度降低，裂纹扩展受到抑制。相反，在大晶粒Ti-O合金中，第一裂纹周围的高应力强度导致裂纹立即扩展和脆性。
Several recent studies reported high ductility in the Ti–O alloy, which is believed to be brittle, but the mechanism explaining the ductility has not yet been clarified. This study focused on the relationship between grain size and ductility to elucidate the mechanism for the high ductility in the Ti–O alloy and found that the ductility decreased with an increasing grain size. Although the extrudate of a Ti-0.77 wt%O sintered alloy exhibited good ductility (>5%) up to a grain size of 49.8 μm, the alloy failed in the elastic area when the grain size exceeded 98.4 μm. Cracks with a size similar to the grain size were observed at the grain boundaries in the fracture area of these ductile fine-grain Ti–O alloys. In situ observations of the deformation behavior of the fine-grain Ti–O alloy revealed that crack propagation was suppressed due to the reduced stress intensity caused by crack refinement. In contrast, in the large-grain Ti–O alloy, the high stress intensity around the first crack caused immediate crack propagation and brittleness.