|英文要約||Title: Research and Development of high absorption, high durability coating for solar receivers using metal oxide (FY2016-FY2017) Final Report
'Development of base layer' We succeeded in making synthetic base material composed metal oxide and TiO2. No crack was observed at heating test 400℃. Small crack was observed at heating test 900℃, but coating was stable after heating test. 'Development of absorption layer’ We succeeded to create micro porous by changed spraying method. The spectral absorptance increased 3% and achieved 96-98% at wavelength 250-2500nm. It is significantly higher than competitors. Absorption was not changed after 1h at 800℃ heating test. Emission was 0.9 at wavelength 7-19µm. 'Development of topcoat layer' We succeeded to create silica material topcoat. The absorption was 96-98% after top coated. ’Development of 3 layers’ We succeeded to create 3 layers (base layer, absorption layer and top coat) with spraying method. 'Making of business plan' We supplied coating samples to user and discuss with them about spec. Their required specifications is high absorption up to 95% and high durability up to 800℃. We created business plan matching to their specification. ‘Improvement and Optimization of 3-layer coating’ As a result of changing the molecular concentration of titanium, the strength of absorption layer was increased. By changing spray method, the absorption was maintaining 96-98%. We succeeded to create new base layer by changing material of base ink, which is much more adhesion to the substrate than last year. For the top layer, we mixed other silica to the top layer ink, we succeeded to raise the absorption. ‘Development of selective absorbing coating for high temperature’ We succeeded to create selective absorbing coating. The absorption was more than 96% (250-2500nm, and saved the absorption during 1-10µm range. ‘Aging test’ Aging test was performed at The Australian National University. Coated on the Inconel625 and stainless steel 316L were executed for temperature value of 600, 750, and 850℃, and ageing times of 10 and 100 hours. Both coating (on Inconel625 and SS316L) had better optical performance and durability than Pyromark coatings (comparative products) for the ageing temperature and times. The reproducibility of the coatings are better than Pyromark. ‘Development of trial products’ We succeeded in coating on the substrate (Inconel625 and SS316L) which are the user’s needs. As a result of Aging Tests, we have passed the specifications necessary for practical application. ‘Brush up of the business plan’ We had a survey of the users, such as the cost, durability test, then brushed up the business plan.