Scholarlink

<p>The tribological and corrosive behaviors of the AA7075 substrate alloyed with chromium (Cr), silicon carbide (SiC), and carbon nanotube (CNT) through laser surface alloying were investigated. The alloying by 40 wt.% Cr, 40 wt.% SiC, and 20 wt.% CNT exhibited effective grain refinement with the lowest grain size of 2.5 microns and the highest hardness of 221 HV. The hardness was approximately 2.6 times that of AA7075 substrate. It is largely due to the formation of hard Cr-C intermetallic compounds (Cr<sub>3</sub>C<sub>2</sub> and Cr<sub>23</sub>C<sub>6</sub>) along with grain refinement. Solid lubricity of CNT particles effectively reduced the coefficient of friction. As a result, the wear coefficient reduced to 1/25th of that of the AA7075 substrate under a 20 N load. The corrosion rate decreased by a factor of 2.3 compared to the substrate, due to the presence of a stable oxide passive layer composed of Cr<sub>2</sub>O<sub>3</sub>, Al<sub>2</sub>O<sub>3</sub>, and SiO<sub>2</sub>. However, excessive addition of Cr and SiC content beyond 40 wt.% reduced the resistance to wear and corrosion. Alloyed sample with excess Cr content suffered with intergranular corrosion due to segregation of Cr-rich compounds at grain boundaries. The sample alloyed with high SiC content experienced galvanic and pitting corrosion because of the presence of undissolved SiC particles. Therefore, optimizing the reinforcement composition is essential for achieving balanced wear and corrosion resistance.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Influence of Composition of Cr-SiC-Carbon Nanotube Powder Mixture on Corrosion and Tribological Performance of AA7075 through Laser Surface Alloying

  • 期刊论文

  • 发表日期：

    2025年8月8日

查看全文
  • Sunil Kumar Pulluru,
  • Faladrum Sharma,
  • Anil Kumar Birru,
  • Uday S. Dixit

摘要

The tribological and corrosive behaviors of the AA7075 substrate alloyed with chromium (Cr), silicon carbide (SiC), and carbon nanotube (CNT) through laser surface alloying were investigated. The alloying by 40 wt.% Cr, 40 wt.% SiC, and 20 wt.% CNT exhibited effective grain refinement with the lowest grain size of 2.5 microns and the highest hardness of 221 HV. The hardness was approximately 2.6 times that of AA7075 substrate. It is largely due to the formation of hard Cr-C intermetallic compounds (Cr3C2 and Cr23C6) along with grain refinement. Solid lubricity of CNT particles effectively reduced the coefficient of friction. As a result, the wear coefficient reduced to 1/25th of that of the AA7075 substrate under a 20 N load. The corrosion rate decreased by a factor of 2.3 compared to the substrate, due to the presence of a stable oxide passive layer composed of Cr2O3, Al2O3, and SiO2. However, excessive addition of Cr and SiC content beyond 40 wt.% reduced the resistance to wear and corrosion. Alloyed sample with excess Cr content suffered with intergranular corrosion due to segregation of Cr-rich compounds at grain boundaries. The sample alloyed with high SiC content experienced galvanic and pitting corrosion because of the presence of undissolved SiC particles. Therefore, optimizing the reinforcement composition is essential for achieving balanced wear and corrosion resistance.