Fine Ni powder is often added to Co and bronze-based metal binder powders for diamond tool segments.Ni is a lower cost substitute for extra-fine Co powder and increases the toughness of Co-Fe diamond binders at the ex...Fine Ni powder is often added to Co and bronze-based metal binder powders for diamond tool segments.Ni is a lower cost substitute for extra-fine Co powder and increases the toughness of Co-Fe diamond binders at the expense of lower hardness and bend strength.In bronze-based diamond binder segments,Ni increases hardness and yield strength.Several grades of Ni powder are used commercially with both Co and bronze-based diamond binders.This paper compares properties of diamond binders containing carbonyl Ni powders including standard Inco(?) T255,T123 PM and T 110 PM.Binder materials were made by ball milling or dry mixing of the fine carbonyl Ni and Fe powders with either XF Co or air atomized bronze(90/10 Cu/Sn) powders.Co-based powder blends were hot pressed at 20～35 MPa and 700℃to 900℃.Bronze-based powder blends were cold pressed and sintered at 840℃.Apparent density,apparent hardness and bend strength(TRS) were compared for different binder compositions and processing conditions.展开更多
The influences of mass concentration of nickel chloride hexahydrate, sodium borohydride, ethylenediamine, pH value, bath temperature on deposition rate were studied with orthogonal experiments by a series of pre-treat...The influences of mass concentration of nickel chloride hexahydrate, sodium borohydride, ethylenediamine, pH value, bath temperature on deposition rate were studied with orthogonal experiments by a series of pre-treatments on micro-diamond particle, and the optimized parameters were obtained. Both the morphology and the composition of original diamond and the diamond with Ni-B coating were analyzed by SEM and XRD respectively. The SEM image shows that the spherical Ni-B particle is coated upon diamond. XRD pattern shows that the coating compositions are Ni and Ni2B.展开更多
Microstructures of surface layer (near diamond) of the metallic film from Fe Ni C system are composed of (Fe,Ni) 3C, (Fe,Ni) 23 C 6 and γ (Fe,Ni), from which it can be assumed that graphite isnt directly catalyzed ...Microstructures of surface layer (near diamond) of the metallic film from Fe Ni C system are composed of (Fe,Ni) 3C, (Fe,Ni) 23 C 6 and γ (Fe,Ni), from which it can be assumed that graphite isnt directly catalyzed into diamond through the film and there exists a transition phase (Fe,Ni) 3C that can decompose into diamond structure. AFM morphologies on the film/diamond interface are traces preserved after carbon groups moving from the film to diamond. The morphologies on the as grown diamond are similar to those on corresponding films, being spherical on (100) face and sawtooth like steps on (111) face. Diamond growth rates and temperature gradients in boundary layer of the molten film at HPHT result in morphology differences.展开更多
Diamond single crystals grown from Fe-Ni-C system at high temperature-high pressure (HPHT) usually contain inclusions related to the metallic catalyst. During the diamond growth, the metallic inclusions are trapped by...Diamond single crystals grown from Fe-Ni-C system at high temperature-high pressure (HPHT) usually contain inclusions related to the metallic catalyst. During the diamond growth, the metallic inclusions are trapped by the growth front or are formed through reaction between the contaminants trapped in the diamond. In the present paper, the metallic inclusions related to the catalyst were systematically examined by transmission electron microscopy (TEM). The chemical composition and crystal structure of the metallic inclusions were for the first time determined by selected area electron diffraction pattern (SADP) combined with energy dispersive X-ray spectrometry (EDS). It is shown that the inclusions are mainly composed of orthorhombic FeSi2, fcc (FeNi)23C6, and orthorhombic Fe3C, hexagonal Ni3C.展开更多
Some dislocations, which are generated in the diamond single crystal during the diamond crystal growth from Fe-Ni-C system, may affect diamond crystal growth mode at high temperature-high pressure (HPHT). The concentr...Some dislocations, which are generated in the diamond single crystal during the diamond crystal growth from Fe-Ni-C system, may affect diamond crystal growth mode at high temperature-high pressure (HPHT). The concentric dislocation loops were successfully examined by Moire images. The surface morphologies of growing and as-grown diamond single crystals were observed by scanning electron microscopy (SEM). The concentric dislocation loops formation process and their effect on the diamond crystal growth mode were analyzed. It should be noted that whatever the nature of the dislocation is, should the Burgers vector of dislocation has a component at the direction normal to the growth interface, the dislocation will make the face parallel to the growth interface grow into spiral face. The presence of consecutive spiral steps on the diamond crystal surface also provides a direct evidence of the dislocation mechanism of diamond crystal growth.展开更多
文摘Fine Ni powder is often added to Co and bronze-based metal binder powders for diamond tool segments.Ni is a lower cost substitute for extra-fine Co powder and increases the toughness of Co-Fe diamond binders at the expense of lower hardness and bend strength.In bronze-based diamond binder segments,Ni increases hardness and yield strength.Several grades of Ni powder are used commercially with both Co and bronze-based diamond binders.This paper compares properties of diamond binders containing carbonyl Ni powders including standard Inco(?) T255,T123 PM and T 110 PM.Binder materials were made by ball milling or dry mixing of the fine carbonyl Ni and Fe powders with either XF Co or air atomized bronze(90/10 Cu/Sn) powders.Co-based powder blends were hot pressed at 20～35 MPa and 700℃to 900℃.Bronze-based powder blends were cold pressed and sintered at 840℃.Apparent density,apparent hardness and bend strength(TRS) were compared for different binder compositions and processing conditions.
基金the National Key Technology R & D Program of MOST(No.2003BA328C)Chinese Nature Science Foundation Committee(No.50472043)+2 种基金Program for New Century Excellent Talents in University(No.NCET-06-0658)the Excellent Young Teachers Program of MOE(No.EYTP 2003-355)Science and Technology Key Project of MOE(No:Key 104136).
文摘The influences of mass concentration of nickel chloride hexahydrate, sodium borohydride, ethylenediamine, pH value, bath temperature on deposition rate were studied with orthogonal experiments by a series of pre-treatments on micro-diamond particle, and the optimized parameters were obtained. Both the morphology and the composition of original diamond and the diamond with Ni-B coating were analyzed by SEM and XRD respectively. The SEM image shows that the spherical Ni-B particle is coated upon diamond. XRD pattern shows that the coating compositions are Ni and Ni2B.
文摘Microstructures of surface layer (near diamond) of the metallic film from Fe Ni C system are composed of (Fe,Ni) 3C, (Fe,Ni) 23 C 6 and γ (Fe,Ni), from which it can be assumed that graphite isnt directly catalyzed into diamond through the film and there exists a transition phase (Fe,Ni) 3C that can decompose into diamond structure. AFM morphologies on the film/diamond interface are traces preserved after carbon groups moving from the film to diamond. The morphologies on the as grown diamond are similar to those on corresponding films, being spherical on (100) face and sawtooth like steps on (111) face. Diamond growth rates and temperature gradients in boundary layer of the molten film at HPHT result in morphology differences.
文摘Diamond single crystals grown from Fe-Ni-C system at high temperature-high pressure (HPHT) usually contain inclusions related to the metallic catalyst. During the diamond growth, the metallic inclusions are trapped by the growth front or are formed through reaction between the contaminants trapped in the diamond. In the present paper, the metallic inclusions related to the catalyst were systematically examined by transmission electron microscopy (TEM). The chemical composition and crystal structure of the metallic inclusions were for the first time determined by selected area electron diffraction pattern (SADP) combined with energy dispersive X-ray spectrometry (EDS). It is shown that the inclusions are mainly composed of orthorhombic FeSi2, fcc (FeNi)23C6, and orthorhombic Fe3C, hexagonal Ni3C.
基金Thi work was supported by the Nstional Natural ScienceFoundation of China (Grant. No 593T1027).
文摘Some dislocations, which are generated in the diamond single crystal during the diamond crystal growth from Fe-Ni-C system, may affect diamond crystal growth mode at high temperature-high pressure (HPHT). The concentric dislocation loops were successfully examined by Moire images. The surface morphologies of growing and as-grown diamond single crystals were observed by scanning electron microscopy (SEM). The concentric dislocation loops formation process and their effect on the diamond crystal growth mode were analyzed. It should be noted that whatever the nature of the dislocation is, should the Burgers vector of dislocation has a component at the direction normal to the growth interface, the dislocation will make the face parallel to the growth interface grow into spiral face. The presence of consecutive spiral steps on the diamond crystal surface also provides a direct evidence of the dislocation mechanism of diamond crystal growth.
