涂层对石墨铸造钛合金界面层组织及性能的影响  

Effect of Coating on Microstructure and Properties of Interfacial Layer of Graphite Cast Titanium Alloy

作　　者：姚谦 刘天翼 刘时兵 李重阳 史昆 曲赫威 YAO Qian;LIU Tianyi;LIU Shibing;LI Chongyang;SHI Kun;QU Hewei(National Key Laboratory of Advanced Casting Technologies,China Academy of Machinery Shenyang Research Institute of Foundry Co.,Ltd.,Shenyang 110022,China)

机构地区：[1]中国机械总院集团沈阳铸造研究所有限公司,高端装备铸造技术全国重点实验室,沈阳110022

出　　处：《材料导报》2024年第S02期434-437,共4页Materials Reports

摘　　要：石墨型铸造是钛合金常用的铸造工艺之一,但界面反应在其浇铸过程中无法避免。本工作为了降低钛铸件的界面反应,通过在石墨模具型腔表面采用人工涂刷以及等离子喷涂工艺制备了不同涂层以改善石墨表面状态,研究涂层对TC4钛合金界面反应的影响。结果表明,人工涂刷的涂层微观表面存在缺陷,浇铸过程中涂层结构遭到破碎,涂层以夹杂物形式存在于金属内部。两种等离子喷涂涂层在降低界面反应上效果显著,相同喷涂功率下APS-Y_(2)O_(3)涂层与石墨结合效果较好,未发生脱落,喷涂8YSZ涂层的合金试样表面上出现残留的涂层组织,但涂层组织并未出现在合金内部。无涂层、人工涂刷Y_(2)O_(3)、喷涂Y_(2)O_(3)和8YSZ涂层界面反应层的宽度分别为154.97μm、68.49μm、48.57μm、44.55μm,在石墨铸型上喷涂涂层可有效降低界面层宽度,且合金试样界面层硬度普遍降低,其中APS-Y_(2)O_(3)和APS-8YSZ试样界面层硬度最低且宽度最小。Graphite casting is one of the commonly used casting processes for titanium alloys,but the interfacial reaction can not be avoided in the casting process.In order to reduce the interface reaction of titanium castings,different coatings were prepared on the surface of graphite mold cavity by manual brushing and plasma spraying to improve the surface state of graphite,and the effects of coatings on the interface reaction of TC4 titanium alloy were studied.The results show that there are defects on the surface of the manual-brushing coating,which leads to the structure of the coating being broken during the pouring process,and the coating exists in the metal in the form of inclusions.The two plasma spraying coatings have remarkable effect on reducing the interface reaction,and the APS-Y_(2)O_(3)coating has a good bonding effect with graphite at the same spraying power,and no shedding occurs.Residual coating structures were found on the surface of the alloy samples sprayed with 8YSZ coating,but no coating structures were found inside the alloy.The width of the interface reaction layer is 154.97μm,68.49μm,48.57μm and 44.55μm,respectively.The width of the interface layer can be effectively reduced by spraying the coating on the graphite cast,and the hardness of the interface layer of the alloy sample is generally reduced.The interfacial layer of APS-Y_(2)O_(3)and APS-8YSZ samples has the lowest hardness and the smallest width.

关 键 词：钛合金 石墨铸型 界面反应 等离子喷涂 

分 类 号：TG146.23[一般工业技术—材料科学与工程]