In situ monitoring of cracking behaviors of plasma-sprayed coatings by the laser acoustic emission technique
In situ monitoring of cracking behaviors of plasma-sprayed coatings by the laser acoustic emission technique
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DOI：
10.1557/jmr.2009.0364
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发表时间：
2009-10-01
影响因子：
2.7
通讯作者：
Ito, Kaita
中科院分区：
文献类型：
--
作者：
Taniguchi, Koichi;Enoki, Manabu;Ito, Kaita
多通道声发射（AE）测量四个激光干涉仪的开发和应用过程中的等离子喷涂过程中，被称为是一个高温过程和一个非常嘈杂的环境中的机械和电气领域。在沉积后的冷却期间可以成功地检测到AE信号，并且清楚地表明，较高的预热温度导致溅射之间和/或涂层与基底的界面处的结合的改善。通过瞬态热应力分析和声发射事件，计算了沉积过程中产生的最大主应力。具有NiCr粘结涂层的钢基底上的氧化铝涂层的裂纹起始的临界应力估计为30，类似于45 Mpa。所开发的技术被证明是一种潜在的工具，用于原位监测的热喷涂过程中，通过该热喷涂涂层的可靠性的增加，可以预期。
Multichannel acoustic emission (AE) measurements by four laser interferometers were developed and applied during a plasma-spray coating process that is known as being a high-temperature process and an extremely noisy environment in both mechanical and electrical domains. The AE signals could be successfully detected during the cooling period after the deposition, and it was clearly indicated that a higher preheating temperature resulted in the improvement of bonding between splats and/or at the interface of the coating and the substrate. The maximum principal stress generated during the deposition process was calculated by the transient heat and stress analysis and the obtained AE events. The critical stress for crack initiation of the alumina coating on a steel substrate with an NiCr bond coat layer was estimated as 30 similar to 45 Mpa. The developed techniques were shown to be a potential tool for in situ monitoring of the thermal spray process, by which an increase in the reliability of thermal spray coatings can be expected.