CaCO3/Ca3(SiO4)O powder mixed with SiO2/modified desulfurization slag for improving theanti-corrosion and heat resistance ability of AZ91DMagnesium alloy

• Main Authors: Jiun-Ran Chang, 張鈞然
• Other Authors: 汪俊延
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/86155673215889778504

碩士 === 國立中興大學 === 材料科學與工程學系所 === 102 === Magnesium alloys have low density and high strength/weight ratio. These characteristic make magnesium alloys being a potential candidates to replace steel and aluminum alloys in many structural and mechanical applications especially in vehicle application. However, magnesium alloy has high electrochemical activity, and therefore a poor corrosion resistance. Besides, magnesium alloys have poor mechanical properties at high temperature. Accordingly, usage of magnesium alloys are not yet widespread. In this study, using CaCO3/Ca3(SiO4)O powder mixed with SiO2 or modified desulfurization slag spraying on the surface of AZ91D. That could improve the anti-corrosion and heat resistance ability of AZ91D. The spray coating layer contain more SiO2 percentage which has better anti-corrosion and heat resistance ability. The result of experiment show that the spray coating layer’s containing 16 wt.% SiO2 thermal diffusivity is 2.9 mm2/s. After 96 hours salt spray test, the spray coating containing 16 wt.% SiO2 corrosion area less than 5%. The adhesion strength of spray coating layer containing 16 wt.% SiO2 is 0.92 MPa. By the result of cross cut test, the spray coating layer containing 16 wt.% SiO2 reached 4B level. On the other hand, the spray coating layer contain more modified desulfurization slag percentage has better anti-corrosion and heat resistance ability. The spray coating layer’s containing 16 wt.% SiO2 thermal diffusivity is 2.9 mm2/s. After the 96 hours salt spray test, the spray coating contains 24 wt.% modified desulfurization slag corrosion area less than 5%. The adhesion strength of spray coating layer containing 24 wt.% modified desulfurization slag is 1.18MPa. By the result of cross tape test the spray coating layer containing 24 wt.% modified desulfurization slag reached 4B level.