Laser glazing of lanthanum magnesium hexaaluminate

✍ Scribed by Yanfei Zhang; Yaomin Wang; Maria Ophelia Jarligo; Xinghua Zhong; Qin Li; Xueqiang Cao

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 457 KB
• Volume: 46
• Category: Article
• ISSN: 0143-8166
• DOI: 10.1016/j.optlaseng.2008.04.001

✦ Synopsis

Lanthanum magnesium hexaalumminate (LMA) is an important candidate for thermal barrier coatings due to its thermal stability and low thermal conductivity. On the other hand, laser glazing method can potentially make thermal barrier coatings impermeable, resistant to corrosion on the surface and porous at bulk. LMA powder was synthesized at 1600 1C by solid-state reaction, pressed into tablet and laser glazed with a 5-kW continuous wave CO 2 laser. Dendritic structures were observed on the surface of the laser-glazed specimen. The thicker the tablet, the easier the sample cracks. Cracking during laser glazing is attributed to the low thermal expansion coefficient and large thickness of the sample.