Potassium titanate （K2O·6TIO2） whiskers-reinforced Al-12Si alloy composites were prepared by the squeeze casting technique. Wear properties of the composites were investigated by pin-on-disc tests under dry con...Potassium titanate （K2O·6TIO2） whiskers-reinforced Al-12Si alloy composites were prepared by the squeeze casting technique. Wear properties of the composites were investigated by pin-on-disc tests under dry conditions. The experimental results showed that K20 ·6TiO2 whiskers can effectively reinforce the matrix alloy and improve the wear resistance of the composite when the volume fraction of whiskers is low at 10 vol%. However, the composites with a high volume fraction of whiskers showed lower wear resistance than the Al-12Si alloy. The main wear mechanism of the composites is clarified as de-lamination and abrasive wear.展开更多
Nickel-phosphorus （Ni-P） composite coatings containing potassium titanate （K2Ti6O13） whiskers （PTWs） were prepared by electroless plating. The surface morphology and component of coatings were investigated by sc...Nickel-phosphorus （Ni-P） composite coatings containing potassium titanate （K2Ti6O13） whiskers （PTWs） were prepared by electroless plating. The surface morphology and component of coatings were investigated by scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDX）, respectively before and after wear test. The tribological performance was evaluated using a pin-on-disk wear tester under dry conditions. It is found that the Ni-P-PTWs composite coatings exhibit higher wear resistance than Ni-P and Ni-P-SiC electroless coatings. The favorable effects of PTWs on the tribological properties of the composite coatings are attributed to the super-strong mechanical properties and the specific tunneling structures of PTWs. The PTWs greatly reinforce the structure of the Ni-P-based composite coatings and thereby greatly reduce the adhesive and plough wear of Ni-P-PTWs composite coatings.展开更多
A group of poly (phthalazinone ether sulfone ketone)/potassium-titanate-whisker (PPSEK/whisker) composites was prepared by coprecipitation from solution. The whisker surface was modified using titanate coupling agent ...A group of poly (phthalazinone ether sulfone ketone)/potassium-titanate-whisker (PPSEK/whisker) composites was prepared by coprecipitation from solution. The whisker surface was modified using titanate coupling agent prior to blending. The tensile, impact, morphology and thermal properties of the moulded composites were investigated. The measurements showed that the tensile strength and impact strength of the composites increased with increasing whiskers content up to 10 to 20 phr, thereafter they showed a decrease in the whiskers content reached 40 phr. At the same time, the modulus of the composites increased with increasing whiskers content. Scanning electron microscopy studies revealed that the whiskers within the composites were dispersed uniformly by treated with coupling agent. Finally, thermogravimetric analysis showed that the heat resistance of the composites tended to increase with increasing whisker content. The results were analysed and discussed in terms of established models of the behaviour of short-fiber reinforced composites.展开更多
The stability of K_2O·8TiO_2 whiskers and the microstructures of the interfaces in K_2O·8TiO_2 whisker reinforced ZL109 aluminum composites under different heat treatment conditions were investigated by mean...The stability of K_2O·8TiO_2 whiskers and the microstructures of the interfaces in K_2O·8TiO_2 whisker reinforced ZL109 aluminum composites under different heat treatment conditions were investigated by means of transmission electron microscopy(TEM) , mostly by high resolution TEM( HRTEM). It was found that K_2O·8TiO_2 whiskers were not very stable.The edge of the whiskers decomposed and a TiO interfacial layer formed during the process of fabricating K_2O·8TiO_2/ ZL109Al composite,and so the interior with increasing temperature and time of heatreatment. Two kinds of interfacial microstructures between the whiskers and the matrix were characterized; one was the TiO layer and the other was a nano scale amorphous transition layer. A few MgAl_2O_4 particles were also observed at the whisker/ matrix interfaces.展开更多
A newly developed whisker K_(2)O 6TiO_(2) reinforced 6061 Al composite was prepared by squeeze casting process. The flexural strength of the composite is 518MPa, and decreases to 490 M Pa after T6 treatment.The hardne...A newly developed whisker K_(2)O 6TiO_(2) reinforced 6061 Al composite was prepared by squeeze casting process. The flexural strength of the composite is 518MPa, and decreases to 490 M Pa after T6 treatment.The hardness of the composite also shows the similar change while T6 treating. The results of HRTEMobservation may explaine this property change. It was considered that there is a continuous TiO layer at the whisker-matrix interface, which is easily to react with the segregated Mg and to form MgTi_(2)O_(4), MgAl_(2)O_(4). The thickening of TiO layer after T6 treatment is the main reason resulting in strength degradation of composite.展开更多
基金supported by the National Natural Science Foundation of China under contract No.10964004Research Fund for the Doctoral Program of Higher Education of China under contract No.20070231001+1 种基金Natural Science Foundation of Gansu province under contract No. 096RJZA104Doctoral Fund of Lanzhou University of Technology under contract No.SB14200801
文摘Potassium titanate （K2O·6TIO2） whiskers-reinforced Al-12Si alloy composites were prepared by the squeeze casting technique. Wear properties of the composites were investigated by pin-on-disc tests under dry conditions. The experimental results showed that K20 ·6TiO2 whiskers can effectively reinforce the matrix alloy and improve the wear resistance of the composite when the volume fraction of whiskers is low at 10 vol%. However, the composites with a high volume fraction of whiskers showed lower wear resistance than the Al-12Si alloy. The main wear mechanism of the composites is clarified as de-lamination and abrasive wear.
基金This work was supported by the National Natural Science Foundation of China(Grant No.50335060)the Excellent Young Teacher Award of the Education Ministry of China(No.[2002]383).
文摘Nickel-phosphorus （Ni-P） composite coatings containing potassium titanate （K2Ti6O13） whiskers （PTWs） were prepared by electroless plating. The surface morphology and component of coatings were investigated by scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDX）, respectively before and after wear test. The tribological performance was evaluated using a pin-on-disk wear tester under dry conditions. It is found that the Ni-P-PTWs composite coatings exhibit higher wear resistance than Ni-P and Ni-P-SiC electroless coatings. The favorable effects of PTWs on the tribological properties of the composite coatings are attributed to the super-strong mechanical properties and the specific tunneling structures of PTWs. The PTWs greatly reinforce the structure of the Ni-P-based composite coatings and thereby greatly reduce the adhesive and plough wear of Ni-P-PTWs composite coatings.
基金the National Natural Science Foundation of China under grant No.59473901 Educational Office Fesearch Project of Liaoning Provice under grant No.2020701095.
文摘A group of poly (phthalazinone ether sulfone ketone)/potassium-titanate-whisker (PPSEK/whisker) composites was prepared by coprecipitation from solution. The whisker surface was modified using titanate coupling agent prior to blending. The tensile, impact, morphology and thermal properties of the moulded composites were investigated. The measurements showed that the tensile strength and impact strength of the composites increased with increasing whiskers content up to 10 to 20 phr, thereafter they showed a decrease in the whiskers content reached 40 phr. At the same time, the modulus of the composites increased with increasing whiskers content. Scanning electron microscopy studies revealed that the whiskers within the composites were dispersed uniformly by treated with coupling agent. Finally, thermogravimetric analysis showed that the heat resistance of the composites tended to increase with increasing whisker content. The results were analysed and discussed in terms of established models of the behaviour of short-fiber reinforced composites.
文摘The stability of K_2O·8TiO_2 whiskers and the microstructures of the interfaces in K_2O·8TiO_2 whisker reinforced ZL109 aluminum composites under different heat treatment conditions were investigated by means of transmission electron microscopy(TEM) , mostly by high resolution TEM( HRTEM). It was found that K_2O·8TiO_2 whiskers were not very stable.The edge of the whiskers decomposed and a TiO interfacial layer formed during the process of fabricating K_2O·8TiO_2/ ZL109Al composite,and so the interior with increasing temperature and time of heatreatment. Two kinds of interfacial microstructures between the whiskers and the matrix were characterized; one was the TiO layer and the other was a nano scale amorphous transition layer. A few MgAl_2O_4 particles were also observed at the whisker/ matrix interfaces.
文摘A newly developed whisker K_(2)O 6TiO_(2) reinforced 6061 Al composite was prepared by squeeze casting process. The flexural strength of the composite is 518MPa, and decreases to 490 M Pa after T6 treatment.The hardness of the composite also shows the similar change while T6 treating. The results of HRTEMobservation may explaine this property change. It was considered that there is a continuous TiO layer at the whisker-matrix interface, which is easily to react with the segregated Mg and to form MgTi_(2)O_(4), MgAl_(2)O_(4). The thickening of TiO layer after T6 treatment is the main reason resulting in strength degradation of composite.
