Diamond Tools Matrix Composites of Co Replaced by Fe with Doping Rare Earth

2012 ◽  
Vol 424-425 ◽  
pp. 848-851 ◽  
Author(s):  
Qing Hua Zou

The experiment on adding rare earth elements doped in diamond matrix composites is made. Based on the doping of rare earth in metal powders including tungsten carbide, iron and nickel, Co is entirely replaced by Fe with rare earth in diamond matrix composites, and the process route of rare earth doping is indicated. The related performance of is measured, and the results obtained show that the bending strength, the hardness and the impact ductility of Fe matrix composites with rare earth are improved. The practical service performance of Fe matrix composites with rare earth has reached up to the practical service performance of Co matrix, and bearing good practical service performance, low price, have made corresponding diamond tools.

2014 ◽  
Vol 692 ◽  
pp. 200-205 ◽  
Author(s):  
Qing Hua Zou ◽  
Zhen Guo Wang

This paper makes the experimental experiment on adding rare earth elements cerium doped in diamond matrix composites. Based on the doping of rare earth in metal powders including tungsten carbide, iron and nickel, the cobalt in diamond matrix is entirely with iron and the process route of rare earth doping is indicated. The performance of matrix composites with rare earth elements and free of rare earth elements is measured and the results obtained show that the flexural strength, the hardness and the impact ductility of matrix composites with rare earth elements are improved and the flexural strength increases by 10~62% over that of the composites free of rare earth elements, and the impact ductility by about 5% correspondently. We have successfully studied out the rare-earth diamond tool matrix composites replacing Co with Fe, bearing good practical service performance and low price, and have made corresponding diamond bit.


2012 ◽  
Vol 430-432 ◽  
pp. 281-284 ◽  
Author(s):  
Yun Bo Lei ◽  
Xue Juan Cao

The curing rate of epoxy/Versamid 125 (V125) by heating curing, room-temperature curing and microwave curing was compared. It is founded that applying microwave technology could effectively improve the curing rate and the curing time is only 3-4minutes. 140W microwave could cure the epoxy system in good condition, but 280W and 420W were easy to make the materials coking. The impact of diluent on mechnical properties of curing product were studied and it is showed that the impact strength increases and the impact ductility will be improved with the content of diluent increases, while the compressing strength, bending strength and tensile strength decrease.


2012 ◽  
Vol 424-425 ◽  
pp. 876-880
Author(s):  
Qing Hua Zou

Research focused mainly on Fe-based matrix composite (the wrapped diamond), used Fe powder to replace the expensive cobalt powder (Co-based matrix composite), and add the rare earth (RE) elements to reinforce the related physical properties of this Fe-based matrix composite for diamond tools. Conducted on the related matrix composite differential thermal analysis (DTA), in particular Fe-based matrix composite containing 35% iron powder (with RE or without RE) Were discussed for DTA and the package insert forces. DTA and the analysis is consistent with the empirical formula. By hot pressing the composite with diamond as the research object, having researched the relationship among the heat capacity (CP) at constant pressure and other related physical parameters (the package inserts force and E etc.). Take 35%Fe-based powder composite materials for diamond tools (with RE or without RE) as the research objiect, combining analysis of the problem for the porosity, and the densification, and the package inserts force, and the DTA tests, which the addition manner of rare earth, add form , and quantity are determined, so that the changes laws of DTA curve and heat capacity (CP) of Fe-based composite containing 35% iron powder( with the RE) are similar to the that of pure Co composites. Apply these laws to improve the hot pressing technology and mechanical properties of the diamond tools (bending strength, impact toughness, hardness and porosity) and so on


2008 ◽  
Vol 1129 ◽  
Author(s):  
A. Kabulski ◽  
V. R. Pagán ◽  
D Korakakis

AbstractAluminum nitride (AlN) films have been explored for sensor and actuator applications, but the resultant piezoelectric coefficient is still too low to make the films more competitive with more commonly used piezoelectric materials such as lead zirconate titanate (PZT). While AlN does have the disadvantage of a lower piezoelectric response, it does have the ability to maintain its piezoelectric properties above 400°C, something that is not possible with other piezoelectric materials. It is desirable to achieve a larger piezoelectric response for AlN in order to facilitate the integration of nitride based devices into existing technologies but conventional methods of improving the response by growing higher quality film only result in slight improvements in the piezoelectric response. A method of improving the d33 piezoelectric coefficient beyond any values found in literature may be possible by exploring methods of improving PZT films.Rare earth doping has been reported to improve the piezoelectric properties of PZT resulting in significant increases in the piezoelectric coefficient. Research has been conducted using rare earth dopants to improve upon the optical properties of AlN, but the impact on piezoelectric effect has never been considered.Thin, 250-1000 nm, AlN:Er films have been reactively sputtered using erbium (Er)/aluminum alloyed targets to explore any improvement in piezoelectric properties of the AlN:Er films as compared to AlN films. AlN films with 0.5 and 1.5% Er concentrations have been found to have piezoelectric coefficients that are larger than comparable ‘Er-free’ AlN films. AlN films with only 0.5% Er quantities were found to increase the d33 coefficient compared to a similar AlN film depending on the thickness of the film. This increase results in d33,f values greater than 7pm/V which is larger than most values found in literature. By increasing the Er content to 1.5%, values of d33,f were found to be as large as 15 pm/V. This enhanced piezoelectric response is still lower than that of PZT, but can be used to create superior actuator devices than that of typical AlN films.


2019 ◽  
pp. 43-48
Author(s):  
Ben Nengjun ◽  
Zhou Pengfei ◽  
Oleksandr Labartkava ◽  
Mykhailo Samokhin

This work involves an analysis of high-chromium high-temperature deformable wieldable nickel alloys for use in GTE repair assemblies. It is shown that the alloys EP868 (VZh98) and Haynes 230 can be used in welded assemblies with an operating temperature of 800-1100 °C. The alloys Nimonic 81, Nimonic 91, IN 935, IN 939, and Nicrotan 2100 GT also have a high potential for use in welded assemblies. They are characterized by a combination of good weldability, high-temperature strength, and resistance to scaling. There have been conducted studies on high-temperature salt corrosion of model nickel alloys. They allowed establishing the patterns of the impact of base metal alloying with chromium, aluminum, titanium, cobalt, tungsten, molybdenum, niobium, tantalum and rare earth metals on the critical temperature of the start of salt corrosion Tcor and the alloy mass loss. It has been established that alloys with a moderate concentration (13-16%) of chromium can possess satisfactory hightemperature corrosion resistance (HTC resistance) under the operating conditions of ship GTE. The HTC resistance of CrAl-Ti alloys improves upon reaching the ratio Ti/Al ˃ 1. Meanwhile, the ratio Ti/Al ˂ 1 promotes the formation of corrosion products with low protective properties. The positive effect of tantalum on the HTC resistance of alloys is manifested at higher test temperatures than that of titanium, and the total content of molybdenum and tungsten in alloys is limited by the condition 8Mo2 – 2W2 = 89. The presence of refractory elements stabilizes the strengthening phase and prevents formation of the ɳ-phase. However, their excess promotes formation of the embrittling topologically close packed (TCP) phases and boundary carbides of an unfavorable morphology. Based on the studies of the HTC resistance, there has been identified a class of model high-temperature corrosionresistant nickel alloys with a moderate or high chromium content (30%), Ti/Al ˃ 1, and a balanced content of refractory and rare-earth elements.


Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1010
Author(s):  
Zachary S. Levin ◽  
Michael J. Demkowicz ◽  
Karl T. Hartwig

We investigated the effectiveness of severe plastic deformation by equal channel angular extrusion (ECAE) for consolidation of metal powders into metal matrix composites. Equal volumes of copper (Cu) and tantalum (Ta) powders were consolidated at ambient temperature via different ECAE routes. Composites processed by ECAE routes 4E and 4Bc were also processed at 300 °C. The resulting materials were characterized by scanning electron microscopy (SEM) and compression testing. Processing by route 4Bc at 300 °C resulted in the highest compressive strength, lowest anisotropy, and least strain rate sensitivity. We conclude that the superior properties achieved by this route arise from mechanical bonding due to interlocking Cu and Ta phases as well as enhanced metallurgical bonds from contact of pristine metal surfaces when the material is sheared along orthogonal planes.


2014 ◽  
Vol 788 ◽  
pp. 329-333
Author(s):  
Rui Zhou ◽  
Xiao Gang Diao ◽  
Jun Chen ◽  
Xiao Nan Du ◽  
Guo Ding Yuan ◽  
...  

Effects of sintering temperatures on the microstructure and mechanical performance of SPS M3:2 high speed steel prepared by spark plasma sintering was studied. High speed steel sintering curve of continuous heating from ambient temperature to 1200°C was estimated to analyze the sintering processes and sintering temperature range. The sintering temperature within this range was divided into groups to investigate hardness, relative density and microstructure of M3:2 high-speed steel. Strip and quadrate carbides were observed inside the equiaxed grains. SPS sintering temperature at 900°C can lead to nearly full densification with grain size smaller than 20μm. The hardness and bending strength are higher than that of the conventionally powder metallurgy fabricated ones sintered at 1270°C. However, fracture toughness of the high speed steel is lower than that of the conventional powder metallurgy steels. This can be attributed to the shape and distribution of M6C carbides which reduce the impact toughness of high speed steels.


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