Tribological behavior studies of chemically bonded phosphate ceramic coatings reinforced with modified multi‐walled carbon nanotubes (MWCNTs)

Abstract

To improve the wear resistance of the chemically bonded phosphate ceramic coatings, MWCNTs are selected as the reinforcement after the modification. The high temperature wear experiment is carried out to investigate the wear behavior of the coatings with different temperatures. The results suggest that, when the temperature is below 500℃, MWCNTs can decrease friction coefficient, and the lowest friction coefficient is about 0.28, but MWCNTs lose the lubricant function at 500℃ and the friction coefficient keeps at the level of ~ 0.68. In addition, the wear resistance of coatings is improved with the introduction of MWCNTs at 100℃ and 300℃ (the wear rate is below 15X10 -3 mm 3 /Nm), but keeps similar level at 500℃ (the wear rate is ~ 22 × 10 −3 mm 3 /Nm). Besides, the wear mechanism of the coatings reinforced by MWCNTs is also investigated based on the wear behavior and microstructural characterizations. MWCNTs improve the fracture toughness by preventing the crack generation and forming the bridge when crack occurs, which leads to smooth wear tracks and good wear resistance of coatings. The coatings with MWCNTs achieve poor wear resistance at 500℃ because MWCNTs lose their strength and resistance to fatigue by oxidizing. K E Y W O R D Sceramic coatings, high temperature, MWCNTs, wear performance

Lactobacillus fermentumHFY06 reduced CCl4-induced hepatic damage in Kunming mice

“…28,29 Recent studies have shown that consuming LAB, such as bidobacteria, can alleviate lipopolysaccharide and D-galactoseinduced acute liver injury. 30,31 Another study showed that combining Lactobacillus plantarum and L-arginine can protect against endotoxin-induced liver damage. 32 CCl 4 -induced liver injury can cause signicant intrahepatic inammation and liver brosis in mice.…”

Strengthening Mechanism of Nanosized Magnesium Silicate Hydroxide on the Tribological Properties of Phosphate-Bonded Solid Coatings

“…On the other hand, tribochemical reactions induced by functional fillers and the counterface are also conducive to the promotion of the wear resistance of composite coatings. 1,2,7−25 As a kind of layered silicate mineral, the main component of natural serpentine is magnesium silicate hydroxide, Mg 3 Si 2 O 5 (OH) 4 , in which silicon-oxygen tetrahedron and magnesia-oxygen (oxyhydrogen) octahedron constitute the basic structural unit (TO layer), and each of them is held together through hydrogen bond and Van der Waals force. The hightemperature stability of natural serpentine is excellent and its layered structure is well maintained even at 600 °C.…”

Influence of Natural Serpentine on Tribological Performance of Phosphate Bonded Solid Coatings

“…Phosphate bonded solid coatings possess superior temperature resistance property. But high brittleness and inferior anti-wear performance of the phosphate binder greatly impede its practical application [8][9][10][11][12][13]. Studies reveled that with appropriate incorporation of functional llers can effectively promote anti-wear performance of the composite coatings [4][5][6][14][15][16][17][18][19][20][21][22][23][24].…”

“…Studies reveled that with appropriate incorporation of functional llers can effectively promote anti-wear performance of the composite coatings [4][5][6][14][15][16][17][18][19][20][21][22][23][24]. Additionally, because process high fracture toughness, brous functional llers can be selected to reduce the brittleness of the composite coatings [11,[25][26][27].…”