Five kinds of WSi_2/MoSi_2 composites were successfully prepared bymechanical alloying, IP and high temperature sintering techniques. And their hardness and fracturetoughness were measured by the Vickers indentation f...Five kinds of WSi_2/MoSi_2 composites were successfully prepared bymechanical alloying, IP and high temperature sintering techniques. And their hardness and fracturetoughness were measured by the Vickers indentation fracture mode through an Hv-10A type sclerometer.The microstructure and morphology were investigated by a JSM-56001V scanning electron microscope.Results show that the addition of 50% WSi_2 (in mole fraction) has remarkable hardening andtoughening effects on the MoSi_2 matrix, whose hardness value and fracture toughness value areincreased about 60% and 86%, respectively. For WSi_2/MoSi_2 composite, the hardening mechanisms arefine-grain and the second phase particles strengthening, and the toughening mechanisms includefine-grain, grain drawing, crack deflection, microbridge and bowing toughening.展开更多
The dry friction and wear characteristics of three kinds of friction couplesunder different loads, MoSi_2/45 tempered steel, MoSi_2/45 quenched steel, and MoSi_2/CrWMn steel,were investigated by using a friction and w...The dry friction and wear characteristics of three kinds of friction couplesunder different loads, MoSi_2/45 tempered steel, MoSi_2/45 quenched steel, and MoSi_2/CrWMn steel,were investigated by using a friction and wear tester. SEM and X-ray diffraction were employed toanalyze the microphotograph of the worn surface and the phase of worn pieces in order to reveal thewear mechanisms of MoSi_2 material. The results show that MoSi_2/CrWMn steel friction pair has gooddry friction and wear properties under the load of 80 N, where the friction coefficient is 0.255 andthe wear rate of MoSi_2 is only 14.72 mg centre dot km^(-1). But under the load of 150 N, it isMoSi_2/45 tempered steel friction pair that has good tribological properties, where the frictioncoefficient is 0.278 and the wear rate of MoSi_2 is only 10.6 mg centre dot km^(-1). The main wearmechanism of MoSi_2 under low loads is brittle fracture. With the increase of load, the main wearmechanism of MoSi_2 against 45 quenched steel or CrWMn steel is adhesive wear. However, the wearmechanism of MoSi_2 against 45 tempered steel is changed from oxidation-fatigue wear to adhesivewear.展开更多
文摘Five kinds of WSi_2/MoSi_2 composites were successfully prepared bymechanical alloying, IP and high temperature sintering techniques. And their hardness and fracturetoughness were measured by the Vickers indentation fracture mode through an Hv-10A type sclerometer.The microstructure and morphology were investigated by a JSM-56001V scanning electron microscope.Results show that the addition of 50% WSi_2 (in mole fraction) has remarkable hardening andtoughening effects on the MoSi_2 matrix, whose hardness value and fracture toughness value areincreased about 60% and 86%, respectively. For WSi_2/MoSi_2 composite, the hardening mechanisms arefine-grain and the second phase particles strengthening, and the toughening mechanisms includefine-grain, grain drawing, crack deflection, microbridge and bowing toughening.
文摘The dry friction and wear characteristics of three kinds of friction couplesunder different loads, MoSi_2/45 tempered steel, MoSi_2/45 quenched steel, and MoSi_2/CrWMn steel,were investigated by using a friction and wear tester. SEM and X-ray diffraction were employed toanalyze the microphotograph of the worn surface and the phase of worn pieces in order to reveal thewear mechanisms of MoSi_2 material. The results show that MoSi_2/CrWMn steel friction pair has gooddry friction and wear properties under the load of 80 N, where the friction coefficient is 0.255 andthe wear rate of MoSi_2 is only 14.72 mg centre dot km^(-1). But under the load of 150 N, it isMoSi_2/45 tempered steel friction pair that has good tribological properties, where the frictioncoefficient is 0.278 and the wear rate of MoSi_2 is only 10.6 mg centre dot km^(-1). The main wearmechanism of MoSi_2 under low loads is brittle fracture. With the increase of load, the main wearmechanism of MoSi_2 against 45 quenched steel or CrWMn steel is adhesive wear. However, the wearmechanism of MoSi_2 against 45 tempered steel is changed from oxidation-fatigue wear to adhesivewear.
