High entropy alloys (HEAs) have attracted great attention ever since they were proposed by Yeh et al. in 2004. Due to special compositions containing five or more metallic elements in equal or near-equal atomic ratio as well as unique microstructures which usually possess simple phases with BCC or/and FCC crystal structures, HEAs possess very interesting properties. For example, the AlCoCrFeNiTi0.5 alloy exhibits a high yield stress of σys=2.26 GPa, a high fracture strength of σfs=3.14 GPa, and a high plastic strain of ε=23.3%. Among mechanical properties, wear behavior is an important factor in many applications. However, so far only little research has been conducted on the wear behavior of HEAs. Chuang et al.reported a superior wear resistance of the AlxCo1.5CrFeNi1.5Tiy HEAs against AISI M2 steel disk compared to conventional steels, due to their lower high-temperature softening rates and higher oxidation resistance. The good wear behavior of HEAs based on AlCoCrFeNiTiy makes it an interesting material to apply as wear-resistant coatings by using surface engineering systems such as thermal spray technology. Up to now, only very few AlCoCrFeNiTi coatings have been produced and investigated by thermal spray technology. Huang et al. reported that the wear resistance of AlSiTiCrFeCoNiMo0.5 and AlSi- TiCrFeNiMo0.5 coatings against Al2O3 abrasive belt was similar to 100Cr6 steel in as-sprayed state. The coatings presented a superior wear resistance against Al2O3 abrasive belt than 100Cr6 and X40CrMoV5-1 steels after being aged at enhanced temperatures, which is explained by precipitation hardening. Lobel et al. investigated different Al- CoCrFeNiTi feedstock materials regarding their suitability for atmospheric plasma spraying. The coatings deposited with atomized powder showed superior wear-resistance against Al2O3 counter body than the coating deposited with mechanically milled powder, due to the more homogeneous microstructure. As an important spraying process, Highvelocity-oxygen-fuel (HVOF) spraying is usually applied to produce dense coatings with low oxide contents and a high bonding strength. However, very few research results dealing with HEA coatings produced by HVOF have been published. Lobel et al. reported that the AlCoCrFeNiTi coating produced by HVOF showed a higher wear resistance against Al2O3 counter body in comparison with a hard chromeplated sample at room temperature. Up to now, no research results related to the wear behavior at elevated temperatures have been reported.
本文由桑尧热喷涂网收集整理。本站文章未经允许不得转载；如欲转载请注明出处，北京桑尧科技开发有限公司网址：http://www.sunspraying.com/
|
