摘要
为提升SLM成形内燃机用Ti600钛合金延伸率并保持原有的屈服强度,本文对SLM制造能量密度工艺参数进行适当调节,实验测试分析其组织和力学性能变化。研究结果表明:无论何种SLM成形Ti600合金下都生成了白色α′相颗粒物。能量密度减小至52 J/mm^3,此时β马氏体发生了较大程度原位分解,有众多α′相析出,形成了针形的α+β组织。Ti600合金的X射线衍射谱图上形成了β相的明显衍射峰,SLM成形期间众多α′相转变为(α+β)组织。能量密度52 J/mm^3合金在保持原有力学强度的条件下使延伸率得到明显增大。能量密度52 J/mm^3合金在断口区域形成了无解理面的韧窝;能量密度60 J/mm^3合金在撕裂棱边缘形成了更多韧窝,具备更优的韧性。
The influence of the energy density on the microstructures,phase-structures and mechanical properties of Ti600 Ti-alloy,an advanced internal combustion engine material manufactured by selective laser melting(SLM)of Ti600 powder,was investigated with X-ray diffraction,scanning electron microscopy,and conventional mechanical probes.The preliminary results show that the energy density had a major impact.To be specific,selective laser melting always produced whiteα′-phased grains.As the energy density decreased to about 60 J/mm^3,formation of quite a fewβ-phase appeared and more dimple fractures existed at the tearing ridges of the Ti-alloy with better toughness;to 52 J/mm^3,only tensile strength significantly increased and in-situ decomposition ofβ-phase martensite induced much precipitation ofα′-phase,accompanied by formation of(α′+β)phased needles,~0.6μm in diameter;to^44 J/mm^3,β-phase content slightly decreased.
作者
杜少杰
李扬
Du Shaojie;li Yang(College of Automotive Engineering,Yellow River Jiaotong University,Jiaozuo 454950,China)
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2020年第6期555-559,共5页
Chinese Journal of Vacuum Science and Technology
