1. 汇报安排

·题目：参加SMT30国际会议总结报告会

·时间：2016年7月19日20:00-21:00

·地点：科技园西五楼北楼会议室A328

·报告人：博1321班-凡正杰、博1601班-王汝家

2. 参加国际会议信息

·会议名称：SMT30 (The 30th International Conference on Surface Modification Technologies)

·会议时间：28th June – 3rd July, 2016

·会议地点：Milan，Italy

·会议简介：The 30th International Conference on Surface Modification Technologies (SMT30) is aimed at fostering research on surface engineering, promoting related international cooperation among scientists and engineers and providing means for the public dissemination of the results from these efforts. SMT30 is intended to cover progress on all aspects of surface modification techniques, from both the macroscopic and microscopic viewpoints. The conference interest includes both industrial materials, e.g., metals, alloys, polymers, ceramics, composites, and advanced materials and processes under development or used in particular applications.

第30届表面改性技术国际会议（SMT30，The 30th International Conference on Surface Modification Technologies）旨在推进表面科学工程的研究与发展，促进相关科学家和工程师的合作与交流。会议涵盖工业材料、金属、合金、聚合物、陶瓷、复合材料、先进材料及先进加工成形技术等方面，是材料、航天、能源、生物工程等领域的国际顶级学术会议，具有较高的学术水平。

·会议交流工作：

Presentation – Effect of Ultrasonic Vibration on Microstructure and Corrosion Resistance of Laser Re-melted Thermal Barrier Coatings.（凡正杰）

Presentation – Effect of Laser Remelting Assisted with Induction Preheating on Microstructure and Thermal Shock Resistance of Laser Remelted TBCs. (王汝家）

3. 参会论文信息

·Title：Effect of Ultrasonic Vibration on Microstructure and Corrosion Resistance of Laser Re-melted Thermal Barrier Coatings.

·Author：Zhengjie Fan, Kedian Wang, Xia Dong * , Rujia Wang, Wenqiang Duan, Xuesong Mei, Wenjun Wang, Shuai Zhang

·Abstract：In this study, plasma sprayed thermal barrier coatings (TBCs) were prepared on 718 nickel-based superalloy and re-melted combined with ultrasonic vibration (UV) and their hot corrosion behaviour in 50 wt.% Na2SO4 + 50 wt.% V2O5 molten salts at 1100 ºC were investigated. The results indicated that the microstructure and corrosion resistance of the laser re-melted TBCs were significantly affected by the ultrasonic vibration power output (UVPO). The TBCs re-melted assisted with low UVPO (~20%, 0.52KW), with flat surface and minor cracks microstructure and enhanced nucleation of equiaxed grains obtained due to the increased convection of low UVPO, exhibited better corrosion resistance compared to other re-melted coatings. A sharp decrease in corrosion resistance of UVLRTs when the UVPO was above 50% (1.3KW) could be attributed to the formation of microstructure with undulated crests and troughs caused by the intensive ultrasonic nonlinear effects (acoustic streaming, mechanical stirring), thus increasing the reactive area between the molten salts and the uneven surface. Moreover, the crater formed in the process of ultrasonic cavitations could also deteriorate the corrosion resistance of the coatings.

·Title：Effect of Laser Remelting Assisted with Induction Preheating on Microstructure and Thermal Shock Resistance of Laser Remelted TBCs.

·Author：Rujia Wang, Kedian Wang, Xia Dong* , Zhengjie Fan, Wenqiang Duan, Xuesong Mei, Wenjun Wang, Shuai Zhang

·Abstract：In the present work, plasma sprayed YSZ thermal barrier coatings based on type 718 Ni-based superalloy are provided with induction preheating and subsequent surface modification by laser remelting. The effects of such operations on the microstructure and thermal shock resistance of laser remelted coatings have also been investigated. The remelted coatings have been characterized by scanning electron microscope. The preheating treatment can significantly affect the evolution of molten pool by reducing thermal gradient and cooling rate, thus contributing to obtaining a relatively finer segmented network cracks and enhanced remelting efficiency as well as inhibitory effect on propagation of segmented network cracks deepening into coatings along the thickness direction. An energy density of 67.9J/cm2 with preheating is qualified for fully remelting TBCs, while 79.2J/cm2 is necessary with non-preheating. This can alleviate excessive thermal damage to ceramic coatings. The results of thermal shock test indicated that the lifetimes of the laser remelted TBCs were significantly affected by the induction preheating and microstructures. The distribution of segmented cracks located in remelted zone influenced by preheating improved the strain accommodation, yet the cracks of deep penetration into coatings may weaken the shock resistance of remelted coatings.

欢迎有兴趣的同学届时前来交流。