Gradient hardening of Ni-based superalloy K403 for enhanced thermal fatigue resistance
Gradient hardening of Ni-based superalloy K403 for enhanced thermal fatigue resistance
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DOI：
10.1016/j.surfcoat.2024.130434
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发表时间：
2024-02
影响因子：
5.4
通讯作者：
Gongbin Tang;Shiyuan Li;Jinfeng Yang;Xinyu Zhou;Rongbing She;Dongwei Li;Tao Zou;Jingwen Wang;Zhongwei Liang
中科院分区：
文献类型：
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作者：
Gongbin Tang;Shiyuan Li;Jinfeng Yang;Xinyu Zhou;Rongbing She;Dongwei Li;Tao Zou;Jingwen Wang;Zhongwei Liang
多晶镍基高温合金广泛应用于航空航天工业。然而，它们长期暴露于极端高温和低温服务环境中经常导致热疲劳裂纹，从而对其寿命产生不利影响。采用超声喷丸技术在K403镍基高温合金表面成功制备了梯度强化层。该处理显著地将表面硬度从374 HV提高到544 HV，并且将残余压应力从-117 MPa增加到-543 MPa。热疲劳测试表明，这种增强层有效地阻止了表面氧化和微观结构退化，将热疲劳裂纹的萌生从50次循环延长到100次循环。实验观察和详细的显微组织演变分析表明，USP在表面上产生了γ和γ′相紧密混合的梯度结构，沿着残余应力，抑制了γ′相在热疲劳循环期间的降解、碳化物析出和扩散。这些发现强调了USP作为表面处理技术的潜力，以显着提高高温合金的热疲劳性能。
Polycrystalline nickel-based superalloys are widely used in the aerospace industry. However, their prolonged exposure to extreme high and low temperature service environments frequently results in thermal fatigue cracks, adversely affecting their lifespan. Herein, a gradient reinforced layer is successfully fabricated on the nickel-based high-temperature alloy K403 using ultrasonic shot peening (USP). This treatment notably enhanced the surface hardness from 374 HV to 544 HV and increased the residual compressive stress from −117 MPa to −543 MPa. Thermal fatigue tests show that this reinforced layer effectively hinder surface oxidation and microstructural degradation, extending the initiation of thermal fatigue cracks from 50 to 100 cycles. Experimental observations and detailed microstructural evolution analysis reveal that USP creates a gradient structure of closely intermingled γ and γ′ phases on the surface, along with residual stress, which inhibits γ′ phase degradation, carbide precipitation, and diffusion during thermal fatigue cycles. These findings underscore the potential of USP as a surface treatment technique to markedly improve the thermal fatigue performance of high-temperature alloys.