Influence of granularity of grinding stone on grinding force and material removal in the rail grinding process

Jiang

et al. 2020

Mater. Res. Express

In this paper, seven copper-zirconia toughened alumina (Cu-ZTA) cermets were prepared by vacuum hot pressing sintering (VHP). The effects of different binder content and different particle size of ZTA particles on the mechanical properties of Cu-ZTA cermets were investigated. The microstructure of the composites was studied by x-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. The hardness of the material was measured by micro Vickers hardness tester. The results show that the solid solution strengthening occurs in the hot pressing sintering process, the formation of copper-based solid solution increases the hardness of the matrix, the highest is192.04 HV 0.1 . The ZTA particles are uniformly distributed in the matrix, and the surface of the ZTA particles is surrounded by a continuous coppermatrix and second phase. Two interfaces are formed between ZTA particles and Cu matrix. One is the ZTA/Cu interface formed by the substitution of Cu atoms for Ni atoms, it is a mechanical meshing interface which extends the service life of cermet under mechanical stress and thermal stress. The other interface is the reaction bonding interface of Cu 3 Ti 3 O and TiO x . The friction and wear test results show that the use of low-diameter ZTA particles and increasing the content of Cu binder will improve the friction and wear properties of Cu-ZTAcermet. Under the action of stress, the fracture occurs at the interface of Cu/ZTA, and the wear, fracture and extraction of ZTA ceramics cause the failure of Cu-ZTA cermet.

Section: Grinding Behavior Of Cu-zta Cermetssupporting

confidence: 92%

Section: Grinding Behavior Of Cu-zta Cermetsmentioning

confidence: 99%

Microstructure and mechanical properties of Cu-ZTA cermet prepared by vacuum hot pressing sintering

Jiang

et al. 2020

Mater. Res. Express

“…Comparing the F10-4, F14-4 and F10-3, F14+16-1 specimens, it can be found that when the particle size of the ZTA particles reduced, the friction coefficient of the friction pair increased, because the low-diameter ZTA particles can be more uniformly dispersed in the matrix, the contact area of ZTA to the matrix can be increased during grinding process, so the friction coefficient increased. Theoretically, the friction coefficient of Fe-ZTA cermets produced after electroless nickel plating should be higher [25]. However, the comparison of F10-1, F10-3 and F10-2, F10-4 specimens did not give a similar trend.…”

Section: Grinding Test Of the Fe-zta Cermetmentioning

confidence: 86%

Microstructure and mechanical properties of Fe-ZTA cermet prepared by vacuum hot-pressed sintering

Jiang

et al. 2020

Mater. Res. Express

The cermet based on metallic iron with zirconia toughened alumina (ZTA) as the reinforcing phase was prepared by vacuum hot-pressed sintering. The ZTA particles were subjected to electroless nickel plating to improve the interfacial bonding ability of ZTA and Fe matrix. In this paper, after electroless nickel plating, the effects of different particle sizes and different contents of ZTA particles on the grinding properties of Fe-based ZTA (Fe-ZTA) cermets were investigated. The results show that the ZTA particles are tightly bound to the Fe matrix. An interface layer is formed between the ZTA particles and the Fe matrix and it can improve the grinding ability of the Fe-ZTA cermet. By reducing the particle size and the content of ZTA particles, the friction coefficient between Fe-based ZTA cermet and the machined surface can be increased, and the surface roughness of the machined surface will reduce. When the ZTA particle size is F14 and the iron binder content is 40%, the friction coefficient between the Fe-ZTA cermet and the steel bar is 0.4981, the surface roughness of steel bar is 40.164 μm, the grinding ratio is 685.952.

Proceedings of the Institution of Mechanical Engineers, Part J:

“…2 The rail grinding can remove and alleviate rail surface damages, thus improving the operation safety and the service life of rails. 3 Therefore, the rail grinding technique has become the most widely used method all over the world to maintain railway lines. 4,5 The rail grinding is in essence a vertical spindle surface grinding process between the end surface of grinding wheel (i.e.…”

Section: Introductionmentioning

confidence: 99%

Grinding force modeling and experimental verification of rail grinding

Ding

Han

Zhou

et al. 2020

Self Cite

Many factors could affect the grinding force during rail grinding processes. Therefore, the grinding force modeling is necessary for predicting the grinding forces under different rail grinding parameter conditions. In this study, 3D models of grinding wheels were constructed based on the surface topographies of real grinding wheels. By means of simulation of rail grinding processes using the DEFORM-3D, the influences of grinding parameters on the grinding forces were explored. Furthermore, in order to verify the simulation results, rail grinding experiments were conducted using a rail grinding friction testing apparatus. Both simulation and experimental results showed that the grinding force increased with the grinding pressure and the granularity of grinding wheel and decreased with the rotational speed of the grinding wheel. A correction factor ks of 0.894 was obtained using the least square method to reduce the error between the simulation and experimental results from 10.22 to 4.42%.