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The effect of particle deformation zone (PDZ) on the microstructure and mechanical properties of SiCp/Mg-5Zn composites was studied. Meanwhile, the work hardening and softening behavior of SiCp/Mg-5Zn composites influenced by PDZ size were analyzed and discussed using neutron diffraction under in-situ tensile deformation. The evolution of FWHM (full width at half maximum) extracted from the diffraction pattern of SiCp/Mg-5Zn composites was used to interpret the modification of dislocation density during in-situ tension, which discovered the effect of dislocation on the work hardening behavior of SiCp/Mg-5Zn composites. In addition, the tensile stress reduction (ΔPi) values during in-situ tension test were calculated to analyze the effect of PDZ size on the softening behavior of SiCp/Mg-5Zn composites. The results show that the work hardening rate of SiCp/Mg-5Zn composites increased with the enlargement of PDZ size, which was attributed to the grain size of SiCp/Mg-5Zn composites increased with the enlargement of PDZ size. Moreover, the stress reduction (ΔPi) values increased continuously during in-situ tensile for SiCp/Mg-5Zn composites due to the increased stored energy produced during plastic deformation, which provided a driving force for the softening effect. However, the effect of grain size on the softening behavior is greater than that of the stored energy, which led to the tensile stress reduction (ΔPi) values of P30 (dPDZ = 30 μm) -SiCp/Mg-5Zn composite were higher than that of P60 (dPDZ = 60 μm) -SiCp/Mg-5Zn composite when the eri were 0.25, 0.5, 0.75 and 1, respectively.

Ceramic coatings were prepared on the surface of 7050 highstrength aluminum alloy using micro-arc oxidation in an aluminate electrolyte with added graphene. To analyze the surface morphology, roughness, phase composition, and corrosion resistance, scanning electron microscopy, X-ray diffraction, X-ray photoelectron, and electrochemical measurements were used, respectively. The addition of 9 g · L-1 of graphene to the electrolyte decreased the micro-pore size of the composite coatings and improved the density. In addition, with the addition of graphene, the roughness was the lowest, and the corrosion resistance was significantly improved.

The effect of asymmetry deformation on microstructure and mechanical properties of AZ31 sheet was investigated in the present paper. Two AZ31 sheets were rolled together with an on-line heating rolling mill and separated from each other afterwards. For each sheet, the strain on both surface during rolling was asymmetry and this rolling method is called asymmetry rolling (AR) in present work. For comparison, symmetry rolling (SR) was also carried out on the same rolling mill that only one sheet was rolled in one pass. The sheets deformed by AR showed more homogeneous microstructure with higher recrystallization level and symmetry distributional basal texture. Moreover, SR sheets showed many narrow shear bands which distributed as “V” shape along rolling direction, while less shear bands with wider size are observed in AR sheet. The shear bands in AR sheet distributed as a line and across the entire thickness of the sheet, resulting in layered bimodal structure. Based on the unique microstructure and texture characteristics, AR sheet has lowest mechanical property anisotropy and a good balance of strength and elongation.

Previous investigations demonstrated that rare-earth elements (REs) could improve their creep properties effectively. Herein, the influence of Y content on the creep properties of magnesium is investigated systematically with different amount of Y additions. The mechanisms responsible for creep deformation are clarified by the analysis of stress exponent and microstructural characterizations. It is found that the addition of Y in Mg can improve both the ambient strength and high temperature strength owing to its effective solid solution strengthening. At room temperature, the yield strength of Mg–Y alloys has a linear relation with the content of Y. When tested at high temperatures, the yield strength reduces. Compared with pure magnesium, Mg–Y alloys exhibit a high thermal stability even above 200 °C. Small amount of Y addition can improve the creep resistance of Mg largely. With further increasing its content, its contribution to the improvement of creep resistance is weakened for Mg. Under the applied stresses 60–100 MPa and at temperatures of 200–250 °C, the responsible creep mechanism is dislocation controlled. During creep deformation, the Y segregation regions play an important role in hindering the movement of dislocations.

Generally, edge crack of rolled magnesium alloy sheets initiates in the RD (rolling direction)-ND (normal direction) plane and then propagate in the RD-TD (transverse direction) plane. Hence, the Mg-2Zn-1.5Mn (ZM21) alloy sheets with and without crack notch were designed to carry out in-situ tensile experiments under 150 °C (the same temperature of rolling), with the aim to understand their crack propagation mechanism. The scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD) techniques were utilized to reveal microstructural evolution in real time at designated displacements. The results show that the prismatic slip, basal slip, and extension twining play synergistic role in coordinating strain during the tensile process in ZM21 alloy sheet at 150 °C. In both tensile samples with and without crack notch, localized strain is mainly concentrated at relatively fine grain area and the grain boundaries or triple junctions of the grains with large basal Schmid factor (SF) difference, which eventually leads to severe surface roughening and subsequent crack initiation. Compared with the sample without crack notch, the pre-cracked sample exhibits severer deformation at the crack tip due to strain concentration. Strain gradient distribution is observed at the crack tip region in the pre-cracked sample. The crack propagation path of the sample with pre-crack is identified and the underlying mechanism is also discussed.

N+ ion irradiation is utilized to tune the structure and mechanical properties of a Cu48Zr47.2Al4Nb0.8 bulk metallic glass composite (BMGC). Ion irradiation increases the disorder near the surface, as probed by neutron diffraction, and, moreover, causes the phase transformation from B2 CuZr to B19’ CuZr martensitic phase in the studied BMGC. The tensile plasticity of the BMGC is dramatically improved after ion irradiation, which results from multiple shear banding on the surface and the martensitic transformation of the B2 to B19’ CuZr martensitic phase. The experimental results are strongly corroborated by complementary molecular dynamic simulations.

The materials used in superconducting magnet coils and in the structural magnet constituents are textured to various extents. This causes an angular dependence of the Young\'s moduli that needs to be taken into account when predicting the stress and strain distribution in the magnets. We have measured by neutron diffraction the texture in metallic materials typically used in superconducting magnets. Based on the neutron diffraction data the elastic anisotropy of the different materials has been calculated. Among the materials studied, the extruded Al oxide dispersion strengthened Cu coil wedges exhibit the strongest elastic anisotropy of 37%. The Young\'s moduli calculated from single crystal elastic constants and grain orientation distributions are compared with highly accurate Young\'s moduli derived experimentally from resonance tests.

Cyclic stability is vital for the application of the elastocaloric effect. We demonstrated here the enhanced cyclic stability in a Ni50.4Mn27.3Ga22.3 alloy via hot extrusion. The fine equiaxed grains with 〈111〉A texture were obtained after hot extrusion at 1323 K. The extruded alloy showed >250 stable elastocaloric cycles without degradation. The mechanism for the enhanced cyclic stability was the presence of fine grains and low energy dissipation related to the 〈111〉A texture. So, hot extrusion may provide a feasible strategy for improving the eCE stability in polycrystalline ferromagnetic shape memory alloys.

The effects of welding speed on the macroscopic and microscopic residual stresses (RSes) in friction stir welded 17 vol.% SiCp/2009Al-T4 composite plates were studied via neutron diffraction and an improved decoupled hierarchical multiscale modeling methods. Measurements showed that the macroscopic and total RSes had the largest variations in the longitudinal direction (LD). Increasing the welding speed led to higher values of measured LD macroscopic and total RSes in the matrix. The welding speed also significantly influenced the distributions and magnitudes of the microscopic RSes. The RSes were predicted via an improved hierarchical multiscale model, which includes a constant coefficient of friction based thermal model. The RSes in the composite plates before friction stir welding (FSW) were computed and then set as the initial states of the FSW process during modeling. This improved decoupled multiscale model provided improved predictions of the temperature and RSes compared with our previous model.

Acta biomaterialia 121, 695 - 712 (2021). doi:10.1016/j.actbio.2020.11.050, The influence of amount of intermetallics on the degradation of as-extruded Mg-Nd alloys with different contents of Nd was investigated via immersion testing in DMEM+10% FBS under cell culture conditions and subsequent microstructural characterizations. It is found that the presence of intermetallic particles Mg$_{41}$Nd$_5$ affects the corrosion of Mg-Nd alloys in two conflicting ways. One is their negative role that their existence enhances the micro-galvanic corrosion. Another is their positive role. Their existence favours the formation of a continuous and compact corrosion layer. At the early stage of immersion, their negative role predominated. The degradation rate of Mg-Nd alloys monotonously increases with increasing the amount of intermetallics. Mg-$_5$Nd alloy with maximum amount of intermetallics suffered from the most severe corrosion. With the immersion proceeding (≥7 days), then the positive role of these intermetallic particles Mg$_{41}$Nd$_5$ could not be neglected. Owing to the interaction between their positive and negative roles, at the later stage of immersion the corrosion rate of Mg-Nd alloys first increases with increasing the content of Nd, then reaches to the maximum at 2 wt. % Nd. With a further increase of Nd content, a decrease in corrosion rate occurs. The main corrosion products on the surfaces of Mg-Nd alloys include carbonates, calcium-phosphate, neodymium oxide and/or neodymium hydroxide. They are amorphous at the early stage of immersion. With the immersion proceeding, they are transformed to crystalline. The existence of undegradable Mg$_{41}$Nd$_5$ particles in the corrosion layer can enhance the crystallization of such amorphous corrosion products., Published by Elsevier, [Amsterdam]

An AlSi3.5Mg2.5 (wt%) alloy with excellent mechanical properties was produced via laser powder bed fusion in this study. The yield strength, tensile strength, and elongation of this as-built AlSi3.5Mg2.5 alloy reach about 406 MPa, 501 MPa, and 8.6%, respectively. These properties are dramatically superior to the current additively manufactured Al-Si-Mg alloys. A direct-aging treatment at 170°C for one hour increases the yield strength and ductility further to about 417 MPa and 11.0%, respectively, with the tensile strength remaining the same level. The microstructures and strengthening mechanisms of the as-built and direct-aged samples were investigated systematically. The underlying micromechanical mechanisms of the as-built and direct-aged samples were examined based on a combination of in-situ synchrotron X-ray diffraction and three-dimensional crystal plasticity modeling. The as-built AlSi3.5Mg2.5 alloy possesses a fine microstructure, including fine grains and nano-sized Mg2Si and Si precipitates. After direct-aging treatment, additional Mg2Si and Si precipitate out. Besides, element diffusion upon aging treatment causes migration of cell boundaries and relaxation of residual stress. The direct-aging treatment leads to an increased Orowan strengthening, dislocation strengthening, and load-bearing strengthening effects. Moreover, the variations of microstructure and residual stress after the aging treatment change the dislocation behavior and increase the dislocation storage capacity, causing an increased ductility. Nevertheless, the aging treatment does not alert the type of damage and fracture. This study provides valuable insights to tailor the microstructure and mechanical properties of additively manufactured Al-Si-Mg alloys.

The AlSi10Mg alloy produced by laser powder bed fusion (LPBF) possesses a novel microstructure and higher mechanical properties compared with its casting counterpart. So far, the crystallographic orientation-dependent lattice strains, average phase stresses, and dislocation density during the tensile loading of the LPBF AlSi10Mg are not well understood. This fact is impeding further optimization of microstructure and mechanical properties. High energy synchrotron X-ray diffraction providing deep penetration capability and phase-specific measurements of various bulk properties of crystal materials is applied to investigate the LPBF AlSi10Mg under loading. The crystallographic orientation-dependent lattice strains and elastoplastic properties of the Al matrix are assessed. The average phase stresses are calculated to quantify load partitioning between the Al and Si phases. The nano-sized Si particles that bear high-stress are efficient strengthening particles. The maximum value of the average phase stress of Si reaches up to ~2 GPa. Based on the modified Williamson-Hall and the modified Warren-Averbach methods, the dislocation density and its evolution during the plastic deformation are determined. A multistage strain hardening behavior is detected in the Al matrix, which is associated with the interactions between the dislocations and the cell boundary network.

The M40 carbon fibers reinforced magnesium matrix composites were fabricated by pressure infiltration method. The interfacial reactions and mechanical properties of the composites were optimized by adjusting the preheating temperatures of the preform (PRT) and the casting temperatures of the melting (CAT). The lower preheating temperatures of preform resulted in casting defects at the interface between carbon fibers and magnesium matrix and making composites rapidly to be failed in a brittle fracture mode. In addition, the higher casting temperatures of melting would result in excessive interfacial reactions at the interface, which would weaken the reinforcement effect of the carbon fibers. When the preheating temperature of the preform was 550 °C and the casting temperature of melting was 760 °C, the moderate interfacial reactions occurred at the interface and the bending strength of the composites reached its maximum value of 1793 MPa.

The content of strain-induced martensite in austempered ductile iron has been quantitatively determined using three different kinds of neutron methods: (1) high-resolution powder diffraction with subsequent standard Rietveld refinement, (2) phase quantification using pole figure measurements and (3) Bragg edge neutron transmission. The accuracy and scope of applications of these neutron diffraction and imaging techniques for phase quantification have been compared and discussed in detail. Combination of these methods has been confirmed as effective for dealing with problems like peak overlap in multi-phase materials and texture formation after plastic deformation. Further, the results highlight the potential of using single peak pole figure data for quantitative phase analysis with high accuracy.

Variant selection during phase transformation creates a specific transformation texture and finally affects the mechanical properties of the alloys. The transformation lattice deformation associated selection mechanism has not been well addressed. In the present work, the α variant selection in a Ti–7Mo–3Nb–3Cr–3Al alloy under isothermal compression at low temperature was investigated. The results show that the selection of the α variants is strongly affected by the imposed strain and the load with the dependence on the effective strain distribution induced by macroscopic shape deformation. In the center region of the compressed sample, 4 Burgers orientation relationship (BOR) variants orienting in four different directions and forming two sets of ‘cross-shaped’ clusters were selected. Such variants consumed the maximum strain contribution to the macroscopic compression. In the edge region of the compressed sample, only 2 BOR variants with 90°/ 2.38 ¯ 0> or 10°/ disorientation relationship were selected. The selection criterion was still obeyed by the variants but with restriction from the local effective strain distribution induced by macroscopic shape deformation. The present work provides the clear information on the interweaving of the imposed compression with the internal lattice deformation and its impact on the β to α transformation variant selection.

Acta materialia 200, 338 - 350 (2020). doi:10.1016/j.actamat.2020.09.017, Orientation related grain growth stimuli during primary and secondary recrystallization of the metal matrix in laminated metal/non-metal composites demonstrate unique effect on orientation evolution but has rarely been investigated. In this work, the recrystallization and grain growth of Cu in a graphene nanosheets (GNSs) reinforced laminated Cu matrix composite during sintering was thoroughly investigated. The microstructure, texture and lattice strain evolution of the Cu/GNS composite was examined referenced to the Cu stack without GNSs by ex-situ and in-situ orientation characterization techniques (SEM-EBSD, neutron diffraction and synchrotron radiation) from mesoscale to macroscopic scale. The results evidenced that a strong Cube orientation was produced in the Cu/GNS composite instead of the individual non-Cube orientations in the pure Cu stack without GNSs. Detailed strain-state analysis of the Cu foils in the Cu/GNS composite revealed that the anisotropic expansion behavior of the GNS that is incompatible with that of the Cu foils imposed multiple elastic constraints to the foils during the sintering process, resulting in a biaxial isostrain state in the surface layers and a uniaxial compressive strainstate in the central layer of each Cu foil. The elastic anisotropy of Cu favors the growth of the Cube oriented grains to minimize the total strain energy. This work clarified the thermal strain induced abnormal grain growth of selected orientations. The mechanism revealed can be useful for analysing abnormal grain growth in elastically strained materials and can also be applied to fabrication process for texturization or even monocrystallization., Published by Elsevier Science, Amsterdam [u.a.]

Elastocaloric cooling is currently under extensive study owing to its great potential to replace the conventional vapor-compression technique. In this work, by employing multiscale characterization approaches, including in situ neutron diffraction in a loading frame, in situ transmission electron microscopy observation at different temperatures, in situ synchrotron X-ray Laue microdiffraction, and high-resolution infrared thermal imaging, we have investigated the thermal and stress-induced martensitic transformation, the stability of superelastic behavior and the associated elastocaloric effect for a Heusler-type Ni50.0Fe19.0Ga27.1Co3.9 single crystal. On the basis of transformation from cubic austenite into monoclinic martensite with a flexibly and reversibly transferring interface, this unique single crystal exhibits a giant elastocaloric effect of 11 K and ultralow fatigue behavior during above 12 000 mechanical cycles. The numerical simulation shows that the Ni50.0Fe19.0Ga27.1Co3.9 alloy offers 18% energy saving potential and 70% cooling capacity enhancement potential compared to the conventional shape-memory nitinol alloy in a single-stage elastocaloric cooling system, making it a great candidate for energy-efficient air conditioner applications.

Layered Ti-Al metal composite (LMC) was designed and fabricated by hot-rolling and annealing of pure Ti and Al sheets. The as-prepared composite exhibits high tensile ductility, being superior to any individual Ti or Al sheets. The stress/strain evolution and fracture behavior of the LMC were analyzed by in-situ observations during the tensile deformation. Three deformation stages of LMC were clearly observed by neutron diffraction: elastic stage, elastic-plastic stage and plastic stage. It is found that stress partitioning at the elastic-plastic deformation stage improves the strain balance of LMC, but leads to an internal stress accumulated at the interface. Additionally, a strain-transfer from Ti to adjacent Al layers relieves the strain localization of Ti layers in LMC, which improves the ductility of Ti. Both stress partitioning and strain localization of Ti layers facilitate the nucleation of cracks at a low macro strain. However, the crack propagation is constrained by layered structure. In terms of the Al layers, the constrained micro-cracks relieve the stress concentration in Al layer and improve the ductility of Al layers, so that cracking indirectly affects the plastic deformation behavior of LMC, then improving its entire ductility. This work provides a new structural strategy towards simultaneously improving strength and ductility to develop high performance LMC by structural design.

Objective: To evaluate the diagnostic value of fluorescence in situ hybridization (FISH) in bladder cancer. Methods: We enrolled healthy volunteers and patients who were clinically suspected to have bladder cancer and conducted FISH tests and cytology examinations from August 2007 to December 2008. Receiver operating characteristic (ROC) curve analysis was performed and the area under curve (AUC) values were calculated for both the FISH and urine cytology tests. Results: A cohort of 988 healthy volunteers was enrolled to establish a reference range for the normal population. A total of 4807 patients with hematuria were prospectively, randomly enrolled for the simultaneous analysis of urine cytology, FISH testing, and a final diagnosis as determined by the pathologic findings of a biopsy or a surgically-excised specimen. Overall, the sensitivity of FISH in detecting transitional-cell carcinoma was 82.7%, while that of cytology was 33.4% (p

The present work attempts to reveal the correlation between the microstructural defects and residual stress in the single crystal nickel-based superalloy, both of which play the significant role on properties and performance. Neutron diffraction was employed to investigate the microstructural defects and residual stresses in a single crystal (SC) nickel-based superalloy, which was subjected to creeping under 220 MPa and 1000 °C for different times. The measured superlattice and fundamental lattice reflections confirm that the mismatch and tetragonal distortions with c/a > 1 exist in the SC superalloy. At the initially unstrained state, there exists the angular distortion between γ and γ’ phases with small triaxial compressive stresses, ensuring the structural stability of the superalloy. After creeping, the tetragonal distortion for the γ phase is larger than that for the γ’ phase. With increasing the creeping time, the mismatch between γ and γ’ phases increases to the maximum, then decreases gradually and finally remains unchanged. The macroscopic residual stress shows a similar behavior with the mismatch, indicating the correlation between them. Based on the model of shear and dislocations, the evolution of microstructural defects and residual stress are reasonably explained. The effect of shear is dominant at the primary creep stage, which greatly enlarges the mismatch and the residual stress. The dislocations weaken the effect of shear for the further creep stage, resulting in the decrease of the mismatch and relaxation of the residual stress. Those findings add some helpful understanding into the microstructure-performance relationship in the SC nickel-based superalloy, which might provide the insight to materials design and applications.

The B2-type intermetallic compounds CoZr and Co39Ni11Zr50 were deformed in tension at low temperatures. While CoZr is ductile down to 4 K, Co39Ni11Zr50 becomes brittle below 125 K due to a martensitic phase transformation. Thermal activation analysis shows that CoZr follows the Cottrell-Stokes law indicating forest dislocation cutting as the dominant rate-controlling deformation mechanism, similar to face-centered cubic metals. The moderate ductility of both intermetallic compounds at low temperatures may qualitatively be related to a significant metallic character of bonding giving rise to a low Peierls stress estimated for primary {110} slip and most likely also leads to an easier activation of secondary {110} slip which was proven by transmission electron microscopy. Secondary slip is necessary for the fulfillment of the von Mises criterion for homogeneous plastic deformation of polycrystalline materials. The present results generalize the findings made on the ductile rare earth intermetallics YAg and YCu and, therefore, may help to search for other ductile systems in the broad class of intermetallic compounds.

International audience; An intensive formation of crystal defects in the α-Al matrix of an as-cast Sr-modified eutectic Al–Si alloy, induced by heat treatment with rapid heating, has been studied. This phenomenon arises from the fragmentation of the Si crystals and the diffusion of Al atoms into the cracks of the Si crystals. During the rapid heating process, a large temperature gradient is established within an as-cast Al–Si sample. It creates a tensile environment for the irregular-shaped and interconnected Si crystals, as the thermal expansion coefficient of the α-Al is ten times that of the Si. Under the thermal constraints, some Si crystals are broken, where the cracks produce the so-called “capillary force” that attracts the surrounding α-Al matrix to fill in them. As the migration of the Al atoms is substitutional, the Al diffusion creates fluxes of vacancies to the interior of the αAl matrix; thus, the crack volume is transferred to the αAl matrix. Due to the homogeneous distribution of the Si crystals and the random presence of the cracks, the αAl matrix is subjected to a varied migration of vacancies in site, in quantity and in direction. Such diffusion is further perturbed by local migration of Al atoms to accommodate the spheroidization of the Si induced by its shape instability. In this way, a large amount of crystal defects (vacancies and then dislocations) are produced in the α-Al matrix. The produced crystal defects then promote the recovery and even recrystallization of the α-Al matrix, resulting in its refinement. Such a mechanism of defect production is applicable to polycrystalline materials composed of phases with incompatible thermal and mechanical properties.

Evolutions of texture and lattice strain of swaged brass samples were investigated by neutron diffraction at STRESS-SPEC under tensile deformation using a unique tension/compression rig. The two phased sample BS1 (61% α-brass and 39% β-brass) became 100% α-brass after 400 °C annealing (sample BS2). The starting texture of the as-received material BS1 was the typical , double fiber. This texture develops firstly by in-situ tension to a moderate strengthening. After annealing (BS2) the fiber survives with surprisingly high strength and develops by in-situ tension a very strong fiber of 39 mrd. Line broadening and lattice strain behaviour shows the development of the elastic strain and plastic strain.

Polycrystalline Ni50.4Mn27.3Ga22.3 alloy with texture was prepared by conventional casting. The alloy exhibited enhanced magnetocrystalline anisotropy after superelastic training. Decent conventional magnetocaloric effect (MCE) with magnetic-field-induced entropy change ΔS = 9.2 J/kg·K under a magnetic field 30 kOe and inverse MCE with ΔS = 2.5 J/kg·K under 5 kOe were demonstrated when the field was applied parallel and perpendicular to , respectively. As a result, large rotating MCE with ΔS = 4.2 J/kg·K under a low field of 20 kOe was achieved at room temperature. This shows that polycrystalline Ni-Mn-Ga alloys may act as promising magnetic refrigerants.

A model for the strain-induced martensitic transformation in austempered ductile iron (ADI) has been developed based on neutron diffraction studies. Quantitative phase analysis was carried out using the Rietveld method including texture analysis. The key parameters applied in this model that influence the strain-induced martensitic transformation are temperature, strain state, and loading type. An empirical relation was derived for the martensite start temperature M s in austempered ductile iron, which takes into account the Ni and carbon content. The M s temperature was used as a scaling parameter for the stability of austenite in the model to describe the strain-induced phase transformation in austempered ductile iron.

Electrochemical machining has the advantage of being free of cathode loss, thermal stress, and residual stress, and is suitable for high precision machining of metal structures. Localization of anodic dissolution can be significantly improved by the side-wall insulation of the cathode. However, for shaped-hole machining, the removal of electrolytic products in the machining gap becomes problematic with the increase of machining depth, which may hinder the machining process. The application of vibration to the cathode in an electrochemical machining is considered an effective approach because the frontal gap is periodically changed by the vibration; therefore, the removal of electrolytic products and the refreshment of electrolyte are facilitated. This study is aimed at finding a suitable method for diamond-shaped hole fabrication using electrochemical machining. The influence of vibrating feed, cathode with and without side-wall insulation on the machining stability and accuracy were studied based on the machining system developed in this study. The experimental results reveal that the machining accuracy of the diamond-shaped hole can be improved remarkably by reducing the width of the tool edge. Meanwhile, the machining stability can be improved significantly with a reasonable vibrating feed mode.