不同B_(4)C含量对冷喷涂Al/B_(4)C复合涂层防腐与耐磨性能的影响

目的分析不同B_(4)C含量对冷喷涂Al/B_(4)C复合涂层防腐和耐磨性能的影响,探索利用冷喷涂低温特点制备Al/B_(4)C复合涂层的可行性。方法利用冷喷涂方法制备4种B_(4)C含量的Al/B_(4)C复合涂层,并利用各种方法表征涂层的结合特征、耐磨性能和防腐性能。结果冷喷涂过程不会改变铝和碳化硼的物相,碳化硼颗粒主要以嵌入方式结合在涂层中,会产生结合缺陷。在本研究中,B_(4)C的质量分数最高可达到34.53%左右,涂层的结合强度随粉末中碳化硼含量的增加先增加、后降低,最高可达26.67 MPa。微区电化学试验分析涂层内部微电位差值,发现Al/B_(4)C界面存在电位差,腐蚀反应会优先在Al/B_(4)C界面发生,从而破坏金属Al成膜,使涂层的耐蚀性能与略低于铝块材。结论冷喷涂技术可以制备微观结构和结合性能良好的高B_(4)C含量Al/B_(4)C复合涂层,涂层中B_(4)C的质量分数最高达34.53%,预期具有良好的热中子吸收性能。同时,B_(4)C颗粒的加入,使得涂层的耐磨性能大大的提升,但是耐蚀性能相比于铝材料略有降低,是未来需要改善的方向。

Influence of B4C Content on Corrosion Behaviour and Wear Resistance of Cold Sprayed Aluminium-based Boron Carbide Composite Coatings

Al/B4C composites materials are widely used as storage vessels for nuclear waste and nuclear reaction shielding device for its excellent anticorrosion, wear resistant and anti-neutron radiation performances. However, Al/B4C composite materials suffer from low structure strength, oxidation and decomposition in sintering process. Cold spray technology is considered to be an ideal method to prepare Al/B4C composites materials. There is few report on the properties influenced by the B4C content. In this paper, Al/B4C composites coatings were deposited on Q235 steel substrate with 4 kinds of B4C content. SEM, SKP, and BS methods were used to characterize the coatings. The results indicate that excellent Al/B4C coating can be deposited by cold spray. The highest bonding strength can reach 26.67 MPa as the B4C is 30%. The coating can decrease the wear rate significantly as the B4C content is more than 20%. But the uniformity of the coating decreases as the B4C content increases, which increase the risk of coating corrosion.