Investigation of cracking prevention in magnetron-sputtered TiAlN coatings during subsequent electron beam hardening
Investigation of cracking prevention in magnetron-sputtered TiAlN coatings during subsequent electron beam hardening
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DOI：
10.1016/j.surfcoat.2017.12.042
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发表时间：
2017-12
影响因子：
5.4
通讯作者：
P. Hollmann;G. Grumbt;R. Zenker;H. Biermann;K. Weigel;K. Bewilogua;G. Bräuer
中科院分区：
文献类型：
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作者：
P. Hollmann;G. Grumbt;R. Zenker;H. Biermann;K. Weigel;K. Bewilogua;G. Bräuer
随后对硬涂层钢进行电子束硬化（EBH），可显著提高基材的承载能力。这种组合处理的成功是基于涂层的抗裂纹形成。本文研究了用电子束（EB）技术在低合金Qt钢（51 CrV 4）上磁控溅射Ti_（1-x）Al_xN硬质涂层在基体硬化过程中的开裂行为。分别研究了厚度为1 μm和3 μm的Ti 0.68 Al 0.32 N和Ti 0.37 Al 0.63 N，从而能够系统地研究裂纹形成，这取决于涂层性能。实验包括仪器压痕硬度测试，X射线衍射和检查的表面和横截面的光学显微镜（LM）和扫描电子显微镜（SEM）以及。结果表明，在电子束硬化过程中，硬质涂层中的残余压应力（σr）对失效有很大的影响。在高温下发生的弛豫过程使σ r显著降低。两个故障机制被区分：一个是与基体材料的热膨胀，而第二个是与严重的表面变形所造成的马氏体相变的钢。
Subsequent electron beam hardening (EBH) of hard coated steels results in a significant improvement of the load-bearing capacity of the base material. The success of this combined treatment is based on the coatings' resistance to crack formation. This paper deals with the cracking behaviour of magnetron-sputtered Ti1-xAlxN hard-coatings on low alloyed QT-steel (51CrV4) during hardening of the base material by means of an electron beam (EB) technology. Ti0.68Al0.32N and Ti0.37Al0.63N with thicknesses of 1 μm and 3 μm, respectively, were studied, enabling systematic investigation of crack formation, which is determined by the coating properties. Experiments included instrumented indentation hardness testing, X-Ray diffraction and examination of surfaces and cross-sections with light microscopy (LM) and scanning electron microscopy (SEM) as well. Results indicated a strong influence of residual compressive stresses (σr) in the hard coatings on failure during EB hardening. It could be detected that relaxation processes occurring at the elevated temperatures, reduced σrsignificantly. Two failure mechanisms were distinguished: one was associated with the thermal expansion of the base material, while the second was related to a severe surface deformation caused by martensitic transformation of the steel.