TiAl合金上陶瓷复合涂层高温稳定性试验研究

Experimental Study on High-Temperature Stability of Ceramic Composite Coatings Based on TiAl Alloy

本文以四乙氧基硅烷和硝酸钾作为原料,采用空气喷涂技术在TiAl合金基体上制备水玻璃陶瓷涂层;同时还在TiAl合金基体上,采用电沉积法制备SiO2做中间层,再以硅酸四乙酯和硅酸钾作为原料,采用空气喷涂技术制备水玻璃陶瓷涂层,得到SiO_(2)^(-)玻璃陶瓷复合涂层,重点研究了两种涂层的抗高温氧化性能。结果表明,水玻璃陶瓷涂层和SiO_(2)^(-)玻璃陶瓷复合涂层使TiAl合金的抗高温氧化能力均有较大幅度的提升。氧化后质量并无大的改变,SiO_(2)^(-)玻璃陶瓷复合涂层仅出现1.13 mg/cm^(2)的增量,水玻璃陶瓷涂层的合金试样增量为14.4 mg/cm^(2),TiAl基体增量为84.8 mg/cm^(2)。随着TiAl基体上涂层厚度的增加,结合强度随之增加,涂层厚度相同时,SiO_(2)^(-)玻璃陶瓷复合涂层的结合强度要高于水玻璃陶瓷涂层。在涂层厚度为3.3μm时,水玻璃陶瓷涂层的结合强度为290.1 MPa,SiO_(2)^(-)玻璃陶瓷复合涂层的结合强度为350.8 MPa,后者比前者提高了20.69%。

In this paper,tetraethoxysilane and potassium nitrate were used as raw materials,and water glass ceramic coating was prepared on the TiAl alloy matrix by air spraying technology.Simultaneously,on the TiAl alloy matrix,SiO_(2)was prepared by electrodeposition as the intermediate layer,and then tetraethyl silicate and potassium silicate were used as raw materials.The water glass ceramic coating was prepared by air spraying technology to obtain SiO_(2)-glass ceramic composite coating,and the high-temperature oxidation resistance of the above coatings was analyzed.The results show that the waterglass ceramic coating and SiO_(2)-glass-ceramic composite coating greatly improve the high-temperature oxidation resistance of TiAl alloy.After oxidation,the mass does not change significantly,only showing an increase of 1.13 mg/cm^(2).The alloy sample coated with water glass ceramic coating is 14.4 mg/cm^(2),and the TiAl matrix is 84.8 mg/cm^(2).With the increase in the thickness of the coating in the TiAl matrix,the adhesiveness force increases,wherein when the coating thickness is the same,the adhesiveness force of SiO_(2)-glass-ceramic composite coating is higher than that of water glass ceramic coating.When the coating thickness is 3.3μm,the adhesiveness orce of water glass ceramic coating is 290.1 MPa,and the adhesiveness strength of SiO_(2)-glass-ceramic composite coating is 350.8 MPa.The latter is 20.69%higher than the former.