Search

Sodium dodecyl sulfate (SDS) and 8-Hydroxyquinoline (8-HQ) intercalated layered double hydroxides (LDH) sheets were in-situ formed in MAO layer to prepare a composite coating (CI@LDH-MAO) on AZ31 magnesium alloy. This composite coating demonstrates commendable anti-corrosion performance, primarily attributed to the formation of LDH sheets and insoluble Mg(HQ) 2 compounds. The electrochemical impedance modulus of the composite coating surpasses that of the MAO coating by three orders of magnitude after immersion of 360 h. Concurrently, the CI@LDH-MAO composite coating exhibits exemplary tribological properties, characterized by a friction coefficient of approximately 0.19 and a wear rate of (11.5 ± 1.5)× 10−6 mm3/(N·m). This outstanding tribological performance can be ascribed to enhanced interaction of lubricants with the friction interface by 8-HQ and SDS anions. • 8-HQ and SDS anions intercalated LDH was in-situ formed in MAO coating. • The composite coating has excellent tribological and anti-corrosion performance. • The COF was reduced by > 80% and the wear rate was reduced by > 50%. • 8-HQ and SDS anions facilitated the interaction of lubricants with friction interface. [ABSTRACT FROM AUTHOR]

Effect of Si addition on the high temperature tribological properties of TiZrV 0.5 Nb 0.5 refractory high entropy alloy was systematically studied. The results demonstrate that Si-microalloying affects the tribological properties by modulating the evolution of tribo-layer. Si-microalloying produces local tribo-layer with strong wear resistance by increasing the sintering rate of wear debris below 600 ℃, ultimately significantly reducing the coefficient of friction and wear rate. At 600 °C, Si-microalloying deteriorates the wear resistance due to the stress concentration at hard particles leading to accelerated fracture of the tribo-layer which hinders the formation of continuous protective tribo-layer. The enhanced tribological properties at 800 °C are attributed to the synergistic effect of suppressed oxide volatilization and rapid oxidation behavior ensuring continuous dense tribo-layer formation. • The high temperature tribological properties of TiZrV 0.5 Nb 0.5 Si x RHEA was studied. • The evolution of the tribo-layer plays a crucial role in the wear process. • The sintering rate of debris determines the formation of tribo-layer below 600 ℃. • A continuous and dense tribo-layer was formed for the Si0.3 alloy at 800 °C. [ABSTRACT FROM AUTHOR]

Inheriting the advantages of bulk metallic glasses (BMGs) and high entropy alloys (HEAs), high entropy bulk metallic glasses (HE-BMGs) have sparked great interest in recent years. In this work, the evolutions of structural heterogeneity, thermal stability and mechanical property of the TiZrHfCuBe HE-BMG with minor Sn addition were characterized, and the corresponding tribological properties under different normal loads and frequencies were investigated. The results showed that minor Sn addition can significantly enhance wear resistance of the HE-BMG by improving its structural heterogeneity and mechanical properties in a rather limited composition range. When excessive Sn is added, plentiful crystal particles are precipitated in the amorphous matrix, and the wear mechanism of the HE-BMG changes from slight abrasive and oxidation wear to severe fatigue and oxidation wear, leading to dramatically declined wear resistance. These findings would provide guidance for the development of advanced HE-BMGs with unique properties. • A rather limited Sn addition could enhance mechanical properties and wear resistances of (TiZrHfCuBe) 1- x Sn x HE-BMGs. • Declined wear resistance of the (TiZrHfCuBe) 0.97 Sn 0.03 was caused by the excessive Sn addition. • The wear mechanisms of (TiZrHfCuBe) 1- x Sn x HE-BMGs change from abrasive and oxidation wear to fatigue and oxidation wear. [ABSTRACT FROM AUTHOR]

Abstract: The high-temperature tribological behaviour of Fe–28Al–5Cr alloy and its composites containing TiC was investigated against a Si3N4 ceramic from 25 to 800°C. The high-temperature wear resistance of the materials was significantly improved by the addition of TiC, which was attributed to the high hardness of the composites, as well as the support role of hard TiC. The oxidation played an important role to friction and wear. [Copyright &y& Elsevier]