Polycrystalline Diamond Research Articles

Wear behavior and impact breakage characterization of PCD teeth of circular saw blades during high-speed sawing of hard aluminum alloy

Polycrystalline diamond (PCD) wear is a classic issue limiting the widespread use of PCD circular saw blades, impairing the final cost and productivity. However, previous studies have rarely focused on the wear of PCD layers of saw teeth considering the vibration effect. Hence, this study aimed to elucidate the wear behavior and impact breakage characteristics of PCD teeth in sawing hard aluminum alloys. Sawing experiments were conducted, while vibration signals and force signals were captured in real-time. Then, wear morphologies of different zones of the PCD tooth were finely characterized and studied by SEM. The results suggested that the main wear types of cutting edges are abrasion, chipping, and adhesion. The abrasive wear was found on the cutting edges, side edges, rake faces, and flank faces. Interestingly, the breakage in chipping zones is mostly marked by grain spalling and cleavage fracture due to binder strength limitations. Adhesive wear occurs in wear zones by EDS analysis. A schematic of the impact wear evolution mechanism is given to explore in detail the wear morphologies of PCD layers. The wear behavior and morphological characterization of the PCD layer are finely discussed considering impact load and sawing factors (e.g., adhesive chips). This study sheds insight into the wear behavior of PCD teeth and guides the design of PCD layers.

Enhanced growth rates of N-type phosphorus-doped polycrystalline diamond via in-liquid microwave plasma CVD

Phosphorus-doped diamond (PDD) exhibits excellent properties, making it suitable for a wide range of applications, such as electronic devices and electrodes. Here, we report the first synthesis of PDD by in-liquid microwave plasma CVD (IL-MPCVD) under high-pressure and low-power conditions. A mixture of methanol (MeOH) and ethanol (EtOH) with triethyl phosphate ((C2H5)3PO4) and (P/C = 1000 ppm) was used for the PDD deposition. Samples were characterized by laser microscopy, Raman spectroscopy, and glow discharge optical emission spectroscopy. Notably, PDD was successfully produced at a growth rate of 280 μm/h, which is two orders of magnitude higher than conventional CVD methods. Additionally, cyclic voltammetry (CV) and impedance spectroscopy (EIS) were used to evaluate the electrochemical properties of PDD. As a result, we confirmed the wide potential window characteristic of conductive diamond and determined that the donor density was [P] = 3.8 × 1017cm⁻³. Therefore, it is clear that IL-MPCVD is applicable for very high growth rates in the CVD process for PDD synthesis.

Research on the Application of Superhard Coating Technology for Cutting Tools in Mechanical Processing

The superhard coating technology for cutting tools has important applications in the field of mechanical processing. This article introduces the development of superhard coating materials for cutting tools, including low-pressure gas-phase synthesis of diamond, cubic boron nitride, and physical vapor deposition (PVD) coating technology. The superhard coating of cutting tools is widely used in turning, milling, tapping, key component machining, high-speed steel drill bits and taps. Research has shown that coatings can reduce cutting forces and improve tool life, but attention should be paid to residual compressive stress. The future development direction includes researching new superhard material cutting tools and developing coating methods that are more wear-resistant and have high temperature hardness.

Machining damage in the fabrication of polycrystalline diamond micro end mill with laser and grinding combined processing method

The high hardness and wear resistance of polycrystalline diamond (PCD) micro tool make it widely used in precision machining of small parts of difficult-to-machine materials. The laser and grinding combined machining is an effective method to fabricate PCD micro tools, but the machining damage is difficult to control, which will reduce the cutting performance and tool life. Therefore, this paper aims to deeply study the damage forms and damage formation mechanisms during the fabrication process of PCD micro end mills, so as to improve the quality of the PCD micro mills. The laser and grinding combined machining experiments of PCD micro end mill are carried out, and the surface morphology characteristics and cutting edge of the mill are observed and analyzed. The influence of process parameters on the fabrication quality of PCD micro mill is investigated. The experimental results show that the high temperature of the laser is the main factor causing damage, which causes the melting and oxidation of the surface material, and further forms micro cracks, pits and oxidized attachments on the PCD mill. In addition, diamond phase transformation and excessive removal of cobalt-rich layer will also lead to graphitization and micro-grooves on the mill surface. For the grinding process, the cutting edge is fractured by the impact of the wheel, resulting in micro notches, micro pits and micro cracks. The intergranular crack expansion of PCD material and cleavage breakage of diamond particles are the main causes of micro cracks and micro pits on the mill surface. In addition, the chips will also scratch the tool surface to produce micro nicks and cause the chips coating on the rake face. The research results are helpful to further understand the damage mechanism of laser and grinding combined machining PCD mill, so as to improve the fabrication quality of micro tools.

Investigation on high-precision drilling of Cf/SiC composites with brazed diamond core-drill

Carbon fiber reinforced silicon carbide ceramic matrix (Cf/SiC) composites have promising applications as lightweight and hot end components due to their unique mechanical and high-temperature properties. However, high-precision drilling of Cf/SiC composites is still a difficult task, which is attributed to material's high hardness, anisotropy, and heterogeneity. In this work, a kind of core-drill with cemented carbide as shank and polycrystalline diamond (PCD) as grits, was prepared with vacuum brazing method. Experiments on drilling of 2D-Cf/SiC composite with the brazed core-drill were carried out. The effects of drilling parameters on the hole dimensional accuracy, surface roughness and defects were investigated. The results showed that with the increase of spindle speed and the decrease of feed rate, the dimensional accuracy was improved and surface roughness was reduced. Delamination, burr, and hole edge collapse were the main defects. The feed rate had a significant influence on the formation of defects. When the feed per revolution was equivalent to the diameter of a single carbon fiber, the defects were reduced effectively and the hole quality was improved substantially. In the investigated range of parameters, the optimal spindle speed and feed rate for high-precision drilling of Cf/SiC composites were 5000 r/min and 30 mm/min, respectively. Under this condition, the hole dimension accuracy was IT 10, and barely defects were observed on the machined surface. The surface roughness of hole sidewall reached a minimum value of 1.9 μm. This work provides a vital process for high-precision drilling on fiber reinforced ceramic matrix composites.

Experimental study on shale-breaking of special-shaped cutter PDC bit

To enhance the drilling efficiency and extend the service life of PDC (Polycrystalline Diamond Composite) bits in shale formations, this study delves into the rock-breaking mechanisms of special-shaped cutters through a comprehensive experimental approach. This involves optimizing the cutter designs, conducting laboratory experiment and field testing. Among the various cutter geometries considered, concave, axe, planar, and triangular cutters are chosen as the focal points for unit rock-breaking experiments. These tests aim to assess their cutting loads and cutting specific energy to gain a deeper understanding of their performance characteristics. Based on experimental, the debris characteristics are analyzed. Based on the understanding of the shale-breaking characteristics of special-shaped cutters, field testing is performed using a novel PDC bit with a special-shaped cutter. Compared with planar cutters, the concave cutter and the triangular cutter generate lower cutting loads and cutting specific energy. Under identical conditions, the average cutting force and cutting specific energy of concave cutter at different cutting depths are reduced by 16.1% and 19.6% Specifically, the concave cutter generates the largest debris when operated under similar conditions, which is beneficial for increasing rock-breaking efficiency. Laboratory experiment indicate that compared to conventional drill bits, the novel drill bit experiences an increase in torque of approximately 9.8% with increasing WOB (weight on bit). Under high WOB, the ROP (rate of penetration) increases by about 75.4%, while the mechanical specific energy decreases by nearly 40%. Additionally, the novel bit vibration characteristics remain superior to conventional drill bits. Field testing shows that the average ROP of the novel bit and total footage drilled increase by up to 13.3% and 27.2%, respectively, in comparison with those for the conventional bit. The research results are helpful to speed up the efficiency of shale gas drilling.

Development, Designing and Testing of a New Test Rig for Studying Innovative Polycrystalline Diamond Bearings

Development, Designing and Testing of a New Test Rig for Studying Innovative Polycrystalline Diamond Bearings

High-performance oxygen terminated synthetic single crystal diamond detector for high gamma dose rate measurement

A high-performance oxygen terminated synthetic single crystal diamond (SCD) detector (4.5 × 4.5 × 0.5 mm3) is presented. The SCD detector exhibits an extremely low leakage current value of 0.29 pA/mm2 with an electric field of 0.3 V/μm. The charge collection spectrum measured with a238Pu source (5.48 MeV α-particles) irradiation shows that the electron and hole charge collection efficiency (CCE) reach as high as 99.1% and 98.9%, with an energy resolution as low as 2.87% and 2.53%, respectively, compared to Si detector. The SCD detector shows excellent radiation hardness and stability under 60Co γ-ray irradiation with a dose rate of 12.737 kGy/h at 150 V bias and is able to withstand a cumulative dose of up to at least 9.3 kGy. The detector output in current mode is linearly related to the dynamic dose rate (0.409 Gy/h-12.737 kGy/h). Similarly, the counting rate of the detector in counting mode exhibits a strong linear variation within the range of 2.6 mGy/h-1269.36 Gy/h. Our results fully indicate that our fabricated SCD detector can be potentially applied to harsh γ irradiation scenarios, which is of guiding significance on real-time dose monitoring.

Anomalously strong size effect on thermal conductivity of diamond microparticles

Diamond has the known highest thermal conductivity of around 2000 W m−1 K−1 and is, therefore, widely used for heat dissipation. In practical applications, synthetic diamond microparticles are usually assumed to have similar thermal conductivity to that of bulk diamond because the particle size is larger than the theoretical phonon mean free path, so that boundary scattering of heat-carrying phonons is absent. In this report, we find that the thermal conductivity of diamond microparticles anomalously depends on their sizes. The thermal conductivity of diamond microparticles increases from 400 to 2000 W m−1 K−1 with the size growing from 20 to 300 μm. We attribute the abnormally strong size effect to the long-range defects during the growth process based on analysis of point defects, dislocations, and thermal penetration depth dependence of thermal conductivity. Our results play a vital role in the design of diamond composites and in the improvement of the thermal conductivity of synthetic diamonds.

Cobalt removal process from PDC with ultrasonication in neutral electrolyte

Cobalt removal is considered a common method to improve the performance of polycrystalline diamond compact (PDC). To effectively reduce the pollution during the process of cobalt removal, a neutral electrolyte was used in this work to remove cobalt from PDC by electrolysis with ultrasonication. The electrode process and mass transfer model of cobalt removal in a NaCl–KCl solution were established by performing electrochemical impedance spectroscopy (EIS) measurements. Different electrode potentials and electrolytic durations were set to investigate the limits of cobalt removal in the neutral electrolyte. Cobalt removal was assessed by conducting potentiodynamic polarisation, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) measurements. The ImageJ2x image analysis software was used to study the collected spectra. The experimental results indicated that cobalt was successfully removed in the neutral electrolyte and that ultrasonication enhanced its removal. The optimal electrode potential for cobalt removal in the NaCl–KCl solution was less than 500 mV or more than 2000 mV. As the electrolysis time increased, the porosity of the PDC surface first increased to 9.4 % and then decreased to 7.2 %, and the depth of cobalt removal was up to 224 μm. Over time, the rate of cobalt removal decreased, suggesting that the efficacy of ultrasonication in promoting the cobalt removal process gradually weakened as electrolysis products continued to accumulate.

Calibration of a constitutive model for polycrystalline diamond sintering process

Polycrystalline diamond is mostly pressed at high temperature in actual production. Thus, circumferential strain data of powder moulding are difficult to collect at high temperatures. As a result, the parameters of DPC constitutive model cannot be obtained using conventional testing methods. Moreover, the use of conventional equipment to test the mechanical properties becomes challenging because of the extremely high hardness and compressive strength of polycrystalline diamond. Sintering tests of polycrystalline diamond were carried out at 1360 °C and 223 Mpa using the spark plasma sintering (SPS) method, and displacement–load data were obtained. The spark plasma sintering experiment of polycrystalline diamond under high temperature and pressure was carried out using the Drucker Prager/Cap (DPC) model with relative density to obtain accurate displacement and load numbers. Combined with USDFLD subroutine, the experiment of polycrystalline diamond sintering was simulated on ABAQUS. Based on the complex method, ABAQUS-MATLAB platform is used for the reverse identification of constitutive parameters. The constitutive model parameters of polycrystalline diamond sintering process are obtained. This approach can describe the mechanical behaviour of polycrystalline diamond powder in the sintering process. In addition, the inverse identification method of the constitutive model in the sintering process of polycrystalline diamond based on ABAQUS and MATLAB solves the problem on the difficulty to observe the sintering of polycrystalline diamond under high temperature and high-pressure environment. Moreover, the constitutive model parameters of the sintering process are obtained, thereby reducing the cost and condition constraints in the actual experiment. A novel technique involves obtaining powder constitutive parameters at high temperature from the sintering point of view. This approach is important to simulate sintering of polycrystalline diamond and its composite products. Foundation itemNational Natural Science Foundation of China (Grant No. 52075438), the Key Research and Development Program of Shanxi Province of China (Grant No. 2020GY-106), the Open Project of State Key Laboratory for Manufacturing Systems Engineering (Grant No. sklms2020010), and the Open Research Fund of Key Laboratory of Oil & Gas Equipment of Ministry of Education (Grant No. OGE201702-110).

Evaluation of cobalt removal from polycrystalline diamond compact in the coupling mechanism of acid leaching and electrolysis

Polycrystalline diamond compact (PDC) is a widely used superhard material, and its thermal stability and wear resistance are the main factors determining its performance. The residual cobalt binder content in polycrystalline diamond (PCD) has a significant impact on the thermal stability and wear resistance of PDC. Therefore, cobalt removal treatment is required to improve the performance of PDC. The current cobalt removal methods mainly include acid leaching and electrolysis. This study proposes a novel coupling method that combines acid leaching and electrolysis for cobalt removal. Cobalt removal was conducted for 10 h under the conditions of electrolytic voltage of 12 V, direct current power supply current of 0.01 A, and sulfuric acid electrolyte concentration of 9.2 mol/L. The cobalt removal effect was evaluated using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The hardness and elastic modulus of PDC before and after cobalt removal were measured using nanoindentation experiments. The results indicate that the coupled electrolysis process effectively removes the cobalt phase in the PCD layer while retaining the WC phase. The hardness and elastic modulus of PDC decrease after the removal of cobalt binder, and the cobalt removal depth can reach 807 μm.

Prediction of formation abrasiveness under the action of a PDC bit based on the fractal dimension of a rock surface

During rock drilling, a drill bit will wear as it breaks the rock. However, there is no uniform grading standard for rock abrasiveness. To solve this problem, the wear mechanisms of a polycrystalline diamond compact (PDC) bit and the formation it is drilling into are analyzed in depth, and an abrasiveness evaluation method based on the fractal dimension of the rock surface topography is established. Initially, a three-dimensional digital model is generated from a scanning electron microscope image of the rock after drilling; next, an evaluation of the irregularities on the rock surface is performed using an adapted Weierstrass–Mandelbrot (W-M) function to ascertain the fractal dimensionality. Then, the microcontact characteristics of the contact surface between the formation and the PDC bit are analyzed, and the distribution of the microconvex contact points of the two-body friction pair in a region is obtained. Because the sliding friction between the drill bit and the rock produces a large amount of heat, according to the contact area formula of the friction surface and heat conduction theory, the temperature rise and overall temperature distribution of the formation and PDC bit under the condition of sliding friction are revealed, and the real contact area between the formation and the drill bit within a certain temperature range is obtained. Finally, the evaluation index of rock abrasiveness under sliding conditions is established by adopting the wear weight loss of the rock cutting tool per unit volume as the index of rock abrasiveness, and the model is verified by a microdrilling experiment. The research in this paper is highly important for improving the rock-breaking efficiency and bit service life during drilling.

Numerical investigation of rock-breaking mechanisms and influencing factors of different PDC cutters during rotary percussion drilling

While drilling deep or ultra-deep wells in hard rock formations, there are significant problems such as easy wear of drilling cutters and a low rate of penetration (ROP), and rotary percussion drilling technology is one of the essential techniques for improving drilling efficiency. However, there is currently limited research on the compatibility of rotary percussion drilling tools, polycrystalline diamond compact (PDC) cutters, and hard rock formations. Considering the motion mechanism of rotary percussion drilling tools, a three-dimensional rock-breaking numerical model was established for different cutters (planar, axe-shaped, and triple-ridged) under impact loads. Penetration depths, cutting widths, and rock-breaking volumes of different cutters under static and dynamic load coupling were analyzed. Changes in tensile, compressive, and shear stresses during the cutter rock-breaking process were compared, revealing the different cutter rock-breaking mechanisms under impact loads. The cutter rock-breaking laws under different impact amplitudes and frequencies were analyzed quantitatively, and the differences in rock-breaking effects of different cutters under various geological conditions were assessed. The results indicated that cutter penetration depth during rotary percussion drilling could be increased by 16.04% compared to that during conventional drilling. Under the same impact load, the rock-breaking effects of different cutters on hard and soft rocks exhibited similar variation patterns. The penetration depth followed the order axe-shaped > triple-ridged > planar cutters, with an average tangential order of triple-ridged < axe-shaped < planar cutters. When drilling through hard rock, the average penetration depths of planar, axe-shaped, and triple-ridged cutters were 5.57, 6.06, and 3.91 mm, respectively. The average tangential forces were 670.57, 541.76, and 347.89 N, respectively. During the transition from soft to hard rock during drilling, the tangential forces of the planar, axe-shaped, and triple-ridged cutters increased by 8.41%, 3.21%, and 2.64%, respectively. The planar cutter experienced the most significant instantaneous tangential-force change and was more prone to impact damage. Increasing the amplitude of the axial stress waves helps enhance the penetration depth of the drill bit, whereas increasing the frequency of the stress waves can reduce the intensity of fluctuations during drill-bit penetration and increase drill-bit stability. The research results provide insights into optimizing drilling cutters and engineering parameters during rotary percussion drilling.

Stick-slip vibration analysis of a coupling drilling-rock system with two delays and one delay-dependent coefficient

Drilling depths exceeding 10,000 m have recently been achieved, but the increasing depth poses challenges due to the flexible drill-string, making it more susceptible to stick-slip vibration. This vibration can lead to accidents such as excessive bit wear and tool falling into the well. Previous studies on modeling polycrystalline diamond compact (PDC) bits have focused on symmetrically distributed complete blade bits, which are not commonly used. To address this gap, this study introduces PDC bits that closely resemble the actual ones, with a structural configuration of both complete blades and part-blades symmetrically distributed. We also consider the impact of mud and rock chips on the drill bit by introducing a delay-dependent coefficient of response damping change. This study develops a stick-slip vibration model for a coupling drilling-rock system with two state-dependent delays tn1 and tn2, and one delay-dependent coefficient. Using the crossing curve method and numerical studies, we obtain different types of crossing curves reflecting the stability switching characteristics of the system in the dimensionless delay τ2τ1 space. During stick-slip vibration, τ1 mutates from 1.69 s to 2.51 s, and τ2 mutates from 1.3 s to 2.16 s, both within the stable region of the crossing curve. The critical steady state and the stable state typically cross the stable and unstable regions of the crossing curve in their respective times. Increasing the torsional damping within the range of 0.04 to 0.08 can accelerate system stabilization or delay the arrival of the critical steady state. Moreover, increasing the drive rotation speed within the range of 4 to 6 eliminates stick-slip vibration and accelerates the system towards a steady state. In conclusion, this study predicts the drill-string dynamics of a symmetrically distributed PDC bit with complete blades and part-blades. The insights gained can help minimize stick-slip vibration and provide recommendations for drilling operation parameters.

Multiscale Simulation of CVD Diamond Growth on (1 0 0)‐, (1 1 1)‐, and (1 1 0)‐Oriented Faces

The growth of chemical vapor deposition diamond in microwave plasma ignited in H2/CH4 gas mixture is investigated using a multiscale approach. The plasma composition and temperatures are determined as a function of the growth conditions using an axial one‐dimensional simulator. The growth process is then studied at the atomic scale using a kinetic Monte‐Carlo simulator developed for (1 0 0), (1 1 1), and (1 1 0) orientations. The calculated growth rates are then injected in a geometric model that predicts the final morphology of the crystal. The simulation of the growth on an etch pit shows that the time necessary to entirely fill the pit is around half an hour. The study of the growth on the three orientations reveals that the surface temperature and methane concentration influence the number, shape, and size of the islands when they appear. On the (1 0 0) surface, the formation of islands may be related to Stranski–Krastanov growth mode, whereas the (1 1 1) surface conducts to Frank–van der Merwe growth mode, and the (1 1 0) surface is governed by Volmer–Weber growth mode.

Unveiling the microstructure and promising electrochemical performance of heavily phosphorus-doped diamond electrodes

The challenge of doping synthetic diamond with phosphorus stems from the atomic size mismatch between phosphorus and carbon atoms, which previously hindered achieving high phosphorus doping levels. This limitation delayed the exploration of phosphorus-doped diamond (PDD) in electrochemical applications, where it holds potential as a novel and appealing electrode material because PDD uniquely combines diamond's exceptional properties with phosphorus atoms inducing n-type conductivity. In this study, heavily doped PDD electrodes were successfully developed using chemical vapour deposition, followed by comprehensive microstructural and electrochemical characterisations. The influence of phosphorus doping, manipulated via high phosphine gas concentration or time-dependant precursor gas flow control, on the PDD properties was thoroughly examined. PDD layers grown at higher phosphine concentrations demonstrated enhanced phosphorus incorporation, leading to a higher prevalence of fine nano-crystalline diamond grains and non-diamond carbon components, while also slowing the growth rate. Notably, a distinct PDD sample produced under dynamic gas flow with lower phosphine concentration revealed larger grain sizes, increased effective deposition rate, and improved phosphorus levels compared to its counterpart synthesized under static conditions. Cyclic voltammetry in a 1 mol L−1 KCl solution revealed a low double-layer capacitance (<11 µF cm−2) in all as-grown PDD electrodes. However, significant differences between the samples emerged during the experiments conducted with redox probes [Ru(NH3)6]3+/2+ and [Fe(CN)6]3−/4−. Particularly, higher phosphorus content promoted well-developed voltammograms, significantly reduced peak-to-peak separation values, faster electron transfer rates, and increased peak currents. Furthermore, the possibility of using heavily P-doped diamond electrodes for the detection of two organic analytes, dopamine and ascorbic acid, was successfully manifested. All in all, the as-grown, highly P-doped diamond electrodes proved their ability, first time ever, to record well-defined signals of both inorganic redox probes and complex organic compounds, unravelling their potential in electroanalysis and sensor development and broadening the scope of PDD utilisation.

Tribological behavior of textured polycrystalline diamond compact for thrust bearings using the surface morphology of dung beetles as an inspiration

To improve the lubrication and friction characteristics of diamond thrust bearings and extend their service life, this study took inspiration from the anti-adhesion and wear-resistant properties of a dung beetle body surfaces and used laser processing to create dimples on the surface of a polycrystalline diamond compact (PDC). The spacing, diameter, and depth of the dimples were designed and optimized using an orthogonal experimental method. The wear mechanism of the textured PDC was analyzed using various microscopic characterization methods. The results showed that the bio-inspired dimple-textured PDC exhibited better tribological behavior and was an effective way to enhance the lifetime and reliability of diamond thrust bearings.

Effect of grain size and cobalt content on machining performance during milling tungsten carbide with PCD tool

Tungsten carbide has been extensively utilized in the manufacturing field due to its exceptional properties. However, traditional methods such as grinding or electric discharge machining often result in a low material removal rate and inevitable surface defects, making tungsten carbide one of the most challenging materials to machine. Milling has emerged as a promising alternative for machining tungsten carbide. However, the milling of tungsten carbide has not been widely applied in the industry due to a lack of comprehensive understanding regarding the milling performance of different tungsten carbides under various conditions. In this paper, a polycrystalline diamond (PCD) tool was used in the milling of tungsten carbides to investigate the effects of tool grain size, workpiece Co content, and WC grain size on tool wear and machining surface quality. It was found that PCD tools with larger grain sizes exhibited higher wear resistance. Additionally, excessive Co content in the workpiece and large WC grain size increased tool wear and degraded the quality of the machined surface. The primary types of tool wear observed in the milling of WC-Co included adhesive wear, abrasive wear, phase change wear, and oxidation wear.

The initial measurement of a compact D-T neutron spectrometer based on a single-crystal chemical vapor deposition diamond stack for fusion plasma diagnostic.

For developing and characterizing a novel compact D-T neutron spectrometer based on a single-crystal chemical vapor deposition diamond stack for plasma diagnostics toward future D-T fusion reactors, the initial measurement was performed using the accelerator-based D-T neutron sources OKTAVIAN at Osaka University. This neutron spectrometer was designed for the detection of 3-17MeV neutrons and operated in the proton recoil telescope configuration by installing a polyethylene converter in front of the diamond stack. The measured neutron energy spectra were obtained by summing the energy of the recoil protons deposited in the diamond stack after the coincidence of the recoil protons identified by the time coincidence analysis. The neutron energy peaks measured by the compact D-T neutron spectrometer were almost in agreement with those obtained by the Monte Carlo N-Particle transport (MCNP) simulation. The energy resolution of the compact D-T neutron spectrometer was emulated to be about 4%-5% in D-T neutron measurement. In future work, the design of the compact D-T neutron spectrometer would be optimized to measure the fusion neutron for plasma diagnostics.