Diamond Composite Materials Research Articles

Effects of Ni–Cr–Mo–Si–B prealloy additives on the properties of Fe-based diamond composites

In this study, Fe-based diamond composites with various Ni–Cr–Mo–Si–B prealloy additives were prepared using hot-press sintering, and the effects of the Ni–Cr–Mo–Si–B content on the relative density, bending strength, Rockwell hardness, and frictional wear properties of the Fe–Cu–Co–Sn matrix were investigated. Additionally, the effect of the composition of the Ni–Cr–Mo–Si–B additives on the interface between the matrix and diamond was studied. The Ni and Cr in the additives facilitated a tight bonding interface without notable gaps between the diamond and Fe–Cu–Co–Sn matrix. Considering the overall performance of the materials, the optimal addition of Ni–Cr–Mo–Si–B was determined to be 10 %, which resulted in notably improved comprehensive performance indicators of the Fe-based diamond composite materials. For example, diamond drill bits made with this formulation exhibited a wear ratio of 1600 mm/g and a penetration rate of 29.21 mm/min, representing increases of 29 % and 44.96 %, respectively, compared to those of drill bits without Ni–Cr–Mo–Si–B additives. Developing high-performance diamond drill bits with increased ROP and extended service lives to enhanced performance, efficiency, and cost-effectiveness in drilling operations across different industries, ranging from mining and construction to oil and gas exploration.

Microstructural Characteristics and Properties of Laser-Welded Diamond Saw Blade with 30CrMo Steel.

In order to enhance the quality of diamond composite materials, this work employs a Cu-Co-Fe and Ni-Cr-Cu pre-alloyed powder mixture as a transition layer, and utilizes laser-welding technology for saw blade fabrication. By adjusting the laser-welding process parameters, including welding speed and welding power, well-formed welded joints were achieved, and the microstructure and mechanical properties of the welded joints were investigated. The results demonstrate that the best welding performance was achieved at a laser power of 1600 W and a welding speed of 1400 mm/min, with a remarkable tooth engagement strength of up to 819 MPa. The fusion zone can be divided into rich Cu phase and rich Fe phase regions, characterized by coarse grains without apparent preferred orientation. The microstructure of the heat-affected zone primarily consists of high-hardness brittle quenched needle-like martensite, exhibiting a sharp increase in microhardness up to 550 HV. Fracture occurred at the boundary between the fusion zone and the heat-affected zone of the base material, where stress concentration was observed. By adjusting the welding parameters and transition layer materials, the mechanical properties of the joints were improved, thereby achieving a reliable connection between diamond composite materials and the metal substrate.

Wear and cutting temperature of thermally stable diamond composite tipped pick in hard rock cutting

Thermally stable diamond composite (TSDC) material has been proposed as a replacement for tungsten carbide (WC) as the cutting-tip material for hard rock cutting due to its high wear resistance and thermal stability. As a new type of rock cutting tool, monitoring the wear and cutting temperature of TSDC cutting tips is of great significance in assessing the application of these picks in the mining and construction industries. A series of rock cutting tests was carried out using TSDC tipped picks. The cutting parameters for these tests were similar to those used in industrial production. The wear on the TSDC tip, assessed as the volume loss (mm3) from the tip per cubic meter of rock removed, was measured by a 3D laser scanner. The temperature of the TSDC tip as it exited the rock was recorded by a high framerate, infrared camera (FLIR X6801). The wear and cutting temperatures of TSDC-tipped picks were compared with conventional WC picks under the same testing conditions. The relationships between wear, cutting temperature and cutting parameters of both materials were analysed and discussed.

Wear of Diamond Composite Materials during Rock Destruction

Wear of Diamond Composite Materials during Rock Destruction

Diamond in the Rough: Toward Improved Materials for the Bone-Implant Interface.

The ability of an orthopedic implant to integrate successfully with the surrounding bone tissue is imperative for optimal patient outcomes. Here, the recent advances and future prospects for diamond-based coatings of conventional osteo-implant materials (primarily titanium) are explored. The ability of these diamond coatings to enhance integration into existing bone, improved implant mechanical properties, facilitate surface chemical functionalization, and provide anti-microbial properties are discussed in context of orthopedic implants. These diamond-based materials may have the additional benefit of providing an osteo-inductive effect, enabling better integration into existing bone via stem cell recruitment and bone regeneration. Current and timely research is highlighted to support the discussion and suggestions in further improving implant integration via an osseoinductive effect from the diamond composite materials.

Effect of basalt fiber on the microstructure and holding strength of sintered WC-based diamond composite

Basalt fiber (BF), a cheap and attractive fiber, was introduced into tungsten carbide (WC)-based diamond composite materials to study the effect of different mass fractions of BF on the structure and performance of WC-based diamond composite materials. The hardness, relative density and bending strength of the samples prepared by hot pressed sintering were tested, and the surface and fracture surface of the samples were analyzed by scanning electron microscope (SEM) and energy spectrometer (EDS). In addition, X-ray diffraction was used for phase analysis of the samples. The results show that adding proper amount of BF can improve the relative density, the bending strength and the holding force of the matrix material. Furthermore, the addition of proper amount of BF activates the sintering process which promotes the infiltration and diffusion of more binder elements on the diamond surface, improving the wettability of the matrix material to the diamond. When the mass fraction of BF is 1%, the composite material has the highest bending strength, and the holding force of the matrix to the diamond is found significantly improved. However, adding excessive BF is unfavorable to the mechanical properties of WC-based diamond composites. In summary, it is feasible and reasonable to add an appropriate amount of BF to replace part of the WC-based powder to prepare impregnated diamond drill bits.

Diamond composite with embedded YAG:Ce nanoparticles as a source of fast X-ray luminescence in the visible and near-IR range

The diamond composite materials with embedded yttrium-aluminum garnet doped with cerium (YAG:Ce) nanoparticles have been produced by microwave plasma-assisted chemical vapor deposition (CVD). Nanoparticles were synthesized by co-precipitation from an aqueous solution while CVD diamond served as the transparent matrix with high thermal conductivity, hardness, and resistivity to radiation damage. The composite films show high-intensity X-ray luminescence (XRL) with a broad band peaking around the wavelength of 550 nm (5d → 4f transition in Ce3+ ion), and a narrow peak of silicon-vacancy (Si–V) centers at 738 nm. The characteristic decay time was measured at τCe < 50 ns for cerium emission and at τSiV∼1 ns for Si–V centers. Excitation spectra of both luminescence types measured near yttrium K-edge (17.1 keV) show a strong correlation, attributed to the excitation of Si–V luminescence by photoelectrons ejected from YAG:Ce nanoparticles. The discovered phenomenon suggests a new way to control X-ray visualization by luminescent diamond composites for fast X-ray detectors and screens.

Research on Design of Polycrystalline Diamond Composite Pendulum Wear-Resistant Belt

The torque impactor can effectively solve the stick-slip vibration of PDC bit in the deep formation, but the wear of the pendulum seriously restricted the service life of the impactor. In order to reduce the wear of the pendulum under complicated working conditions, the polycrystalline diamond composite material was used as the wear-resistant material to design the pendulum wear-resistant belt. Based on the analysis of the feasibility of using polycrystalline diamond as pendulum wear-resistant material, the finite element model of dynamic contact interaction between pendulum wear-resistant belt and impact cylinder was established, the influence of the arrangement of wear-resistant blocks on the stress of the contact area between the pendulum wear-resistant belt and the impact cylinder was studied. The results show: Polycrystalline diamond composite material has stronger wear resistance and better anti-friction performance than conventional wear-resistant materials, and can reduce the wear of the inner wall of the impact cylinder, which is feasible on the surface of the pendulum hammer. The use of the wear-resistant belt structure is beneficial to improve the variation of the shear stress of the area where the pendulum and the impact cylinder contact each other. The wear-resistant belt structure is beneficial to improve the shear stress variation amplitude of the pendulum and impact cylinder in contact with each other. When the wear-resistant block is arranged in a circular block staggered arrangement, the shear stress change amplitude of the interaction contact area is the largest, the triangular block staggered arrangement mode is second, and the trough block shape staggered arrangement is the smallest. The research results have important reference significance for the design and application of polycrystalline diamond composite pendulum wear-resistant belt.

Influence of the Addition of Vanadium Nitride on the Structure and Specifications of a Diamond–(Fe–Cu–Ni–Sn) Composite System

This article discusses the influence of the addition of vanadium nitride on the mechanical and operational properties of diamond composite material based on metallic bond comprised of iron, copper, nickel, and tin obtained by sintering in a mold at 800°C for 1 h with subsequent hot repressing. It has been established that the addition of vanadium nitride in the amount of 2 wt % to diamond–(51Fe–32Cu–9Ni–8Sn) increases the ultimate compressive strength from 846 to 1640 MPa and bending strength from 680 to 1120 MPa, as well as decreases the wear intensity of the composite material from 0.0069 to 0.0033 g/km. The mechanism of improving the tribological properties has been revealed.

Synthesis of nanostructured composite material based on nanodiamonds modified by silicon

Composite nanostructured powder nanodiamond–SiC with particles of size from 0.1 to 5 μm is synthesized on the basis of nanodiamonds modified by carbon and silicon under vacuum annealing. A compact diamond composite material consisting of nanostructured grains of size 0.2-0.5 microns is formed as a result of high pressure-high temperature sintering of the powder under the pressure range of 1.0-2.5 GPa. The mechanical milling of the synthesized compacts makes it possible to obtain a polycrystalline diamond micropowder with submicron- and nanocrystalline structure with particles of size up to 50 μm.

Influence of pulsed current during high pressure sintering on crystallite size and phase composition of diamond with Ti[sbnd]B bonding phase

Diamond production by sintering and synthesis is known from the mid-fifties of the twentieth century. The sintering technology of PCD materials has not significantly changed even to this day. Nonetheless, there are publications providing a lot of success in the field of synthesis of diamond composite materials sintering using SPS technology, yet these studies are limited to pressures mainly up to 140MPa. In this work HP SPS (High Pressure Spark Plasma Sintering) device, was used to sinter diamond composite with titanium‑boron bonding phase. Thus obtained material was then compared with HP-HT (High Pressure High Temperature) sintered sample, to investigate the influence of the heating by means of direct pulsed current on the crystallite size and phase composition of diamond with 10wt% of Ti+2B bonding phase. Both HP SPS and HP-HT processes were carried out at 8.0±0.2GPa and at the temperature of 1650±50°C during 20s of holding time. The XRD analysis carried out showed that the different type of current used for heating has significant influence on kinetics of the sintering, which is visible in differences in phase composition and level of lattice strain, when comparing standard HP-HT with HP SPS methods.

Evaluation of the characteristics of diamond grinding wheels at their production and operation stages

The evaluation of important characteristics of the diamond-bearing layer of grinding wheels contributes to improving the effectiveness of diamond grinding of hard-to-work materials. This evaluation is carried out by applying 3D simulation methodology utilizing the finite element method. The whole life cycle of diamond composite materials, from development and production to operation, is considered. More specifically, the effect of the number of metal phase inclusions within the diamond grain during sintering is studied. Furthermore, a novel approach for investigating the influence of diamond grain wear during grinding, on the grain, is presented. Models exhibiting the impact of diamond grain orientation are also discussed. Finally, the value of grain embedment in bond is investigated. The proposed methodology makes it possible to determine the contribution of force and thermal factors in deflected mode of the diamond-bearing layer in the sintering of grinding wheel and in grinding operation. The role of such factors as grade of grain and wheel bond, relative orientation, and degree of wear of diamond grains can be evaluated during development, production, and operation of diamond composite materials.

Diagnostics of service performance of diamond powders and diamond powder-based composite materials

Diagnostics of service performance of diamond powders and diamond powder-based composite materials

MANUFACTURING TECHNOLOGY OF DRILL BITS UNDER HIGH PRESSURE AND TEMPERATURE WITH THE APPLICATION OF NEW DIAMOND MATERIALS

An original manufacturing technology of diamind drill bits with up to 212 mm at pressures up to 1.5 GPa and temperatures up to 1250 °C was developed. The bits were produced by sintering in a heat insulating jacket, an electrical insulating casing with electri cal heaters in a steel high pressure cell for 120 min. In the manufacture of drill bits by sintering under high pressure in steel HPC it was found that the sintering process is productive and apparatus for it can be used repeatedly. It can be used steel casing for pressing the diamond matrix material on it. The whole body can be made of diamond powder or holes for fi xing of diamonds by the subsequent soldering or by mechanical method. The authors have developed and manufactured a piston-cylinder type of HPC with a working diameter up to 280 mm by a high-pressure chamber. Also they have made a bit of model cutting elements such as polycrystalline carbonado diamonds and have tested their performance properties. When drilling of marble unit at load of 50 kN and the revolutions number of 355 rev/min the mechanical speed was reached up to 20 m/h. It was found that the developed technology allows to keep cutting properties such as carbonado diamonds have, which are analogues of PCD for thermal stability. Strength bit performance allows its operation under the most intense power drilling modes; metal-ceramic matrix provides a reliable fastening of the cutting elements. Carbonado is wear resistant and has high strength. This technology is energy effi cient, environmentally friendly and productive, as the technology can be used for the manufacture of metalceramic wear-resistant, corrosion-resistant casing bit and then fi xing it in the diamond cutting elements by soldering, or mechanical fastening, using a diamond composite materials of PCD types with diff erent thermal stability.

Self-assembling WC interfacial layer on diamond grains via gas-phase transport mechanism during sintering of metal matrix composite

Diamond wire saws are widely used in machining of high strength reinforced concrete and steel structures. In such operation conditions, the tools wear down rather quickly, which has significant technical and economic implications. Currently, there are three main ways to improve a quality of diamond cutting tools: increasing (1) strength of a binder (metal matrix), (2) diamond grain grade and (3) adhesion strength between diamond and a binder. In this work, an effective approach involving simultaneous improvement of (1) and (3) during diamond composite material sintering is reported. The mechanism of spontaneous formation of WC layer on a diamond surface during sintering with metal matrix composite in the presence of WC nanopowder as a reinforcing additive is studied. The layer is formed via gas-phase transport mechanism leading to chemisorption of volatile tungsten oxide WO3 onto a diamond surface followed by WO3 reduction and carbide formation. The simultaneous enhancement of mechanical properties of the binder and formation of protective WC interfacial layer on diamonds provide a synergistic effect, which results in increased productivity and cutting speed of diamond tools.

Cu/synthetic and impact-diamond composite heat-conducting substrates

Composite material with high thermal conductivity was obtained by the method of thermal sintering of diamonds (synthetic and impact) and copper powder and by further hot isostatic pressing. The content of diamond (the particle size is 20 - 250 μm) in the diamond copper composite was 30 - 45 weight percent. The coefficient of thermal conductivity of copper diamond composite materials based on synthetic diamonds was measured to be 700 - 750 Wm-1K-1. The coefficient of thermal conductivity of copper diamond composite materials based on impact diamonds was measured to be 850 - 900 Wm-1 K-1. The coefficient of thermal expansion (CTE) was measured to be 5.5 - 6.5 • 10-6/°C for synthetic diamonds and 6.1 - 6.5 •10-6/°C for impact diamonds. The obtained copper diamond composite materials are promising to be used as crystal holders for semiconductor crystals in THz and microwave devices.

Cu/Diamond composite heat-conducting shims

Composite material with high thermal conductivity was obtained by the method of thermal sintering of a diamond (50 – 75%) with a size of 20 to 250 μm in a matrix of copper.Coefficient of thermal conductivity of copper diamond composite materials was measured and is 450 – 650 W·m-1·K-1. The coefficient of thermal expansion CTE was measured and is 5.5 – 7.5 · 10-6/°C. The obtained copper diamond composite materials are promising objects for use in THz and microwave devices.

Wear performances and mechanisms of ultrahard polycrystalline diamond composite material grinded against granite

The wear characteristics of a novel ultrahard polycrystalline diamond (UHPCD) were verified comparing with polycrystalline diamond (PCD) through a lathe used here by grinding against granite. The wear ratios of UHPCD and PCD against granite in grinding were calculated according to the sample weight loss. The hardness and the wear morphologies of UHPCD and PCD were characterized by a micro hardness tester, a confocal laser scanning microscope (CLSM) and a scanning electron microscope (SEM). Additionally, both UHPCD and PCD were used in the manufacture of the core drilling bits. The field application tests of the bits were carried out. The results showed that the wear resistances of UHPCD under different rotate speeds are about two times than that of PCD. A cambered face which was fitted to the granite column surface formed at the end face of PCD after the wear process. Differently, a convex structure with the cutting edge of CVD diamond formed at the end face of UHPCD. The hardness of the core of UHPCD (105–115GPa) which is higher than that of PCD (53–57GPa) led to the different wear topographies. Higher hardness with a strong support contributes to a superior wear resistance performance. The results of field application tests reveal that the lifespan of UHPCD bits (up to 132.33m) is superior to that of PCD bits (up to 83.76m). These findings provide a basis for further geological application of UHPCD.

Thermal stability of ultrahard polycrystalline diamond composite materials

Thermal stability of the ultrahard polycrystalline diamond (UHPCD) composite material developed by the reinforcement of the polycrystalline diamond (PCD) with chemical vapor deposition (CVD) diamond has been investigated in a flow of argon at 1200°C. The indentation, Raman spectra and wear test have been performed to compare hardness, C-C structure and wear resistance of untreated and thermal treated UHPCD. It has been shown that the hardness of CVD diamond in UHPCD attains 133 ± 7 GPa after high pressure and high temperature (HP-HT), while after thermal treatment the hardness decreases to 109 ± 3 GPa, and the wear resistance of the thermal treated UHPCD decreases from 0.17 to 0.6 mg/km. The narrowing of full width at half maximum (FWHM) and shift of Raman peak to lower frequencies of CVD diamond in thermal treated UHPCD imply a decrease of crystal structural defects and compressive stresses, which results in a drop of the hardness of CVD diamond in a thermal treated UHPCD. The higher wear rate of thermal treated UHPCD is due to the lower hardness.

Hardness of single-crystal CVD diamond and phase transformations in it on indentation

Hardness of single-crystal CVD diamond placed into a shell of a diamond composite thermostable material produced at high pressures and temperatures as well as structural variations in diamond during indentation have been studied.