近β钛合金表面包覆渗氧强化

利用一种钛合金表面防护涂料对近β钛合金Ti-1023进行表面包覆后,在不同温度和气氛环境下进行高温渗氧强化处理。对渗氧处理后的合金表层显微组织和硬度梯度进行表征。结果表明,涂层包覆可以有效减缓Ti-1023合金的高温氧化行为,抑制表面疏松的脆性氧化物的形成,提高合金表面硬度。在空气气氛下,经850 ℃×24 h渗氧处理后Ti-1023合金表层显微硬度由321 HV0.2提高到544 HV0.2,硬化深度达500 μm以上。在T_β以下750 ℃氧气气氛中渗氧48 h后,合金表层显微硬度可达459 HV0.2,并且合金基体组织基本不受影响。

Surface oxygen diffusion strengthening of near β titanium alloy by pre-coating

Oxygen diffusion on near β titanium alloy Ti-1023 with surface protection coating was conducted at different temperatures and in different atmospheres. The superficial microstructure and microhardness gradient of the alloy were characterized. The results indicate that the high temperature oxidation behavior of the alloy is repressed with surface coating, leading to formation of dense oxygen diffusion layer rather than porous brittle oxides, which can increase the surface hardness of the alloy. In the air atmosphere, the surface microhardness of the Ti-1023 alloy increases from 321 HV0.2 to 544 HV0.2, with the depth of over 500 μm when treated at 850 ℃ for 24 h. When treated at 750 ℃ for 48 h, which is below T_β temperature in oxygen, the surface microhardness can be raised to 459 HV0.2 with basic structure maintained.