Hao Du

Guizhou University · School of mechanical engineering

Bipolar high-power impulse magnetron sputtering (HiPIMS) is used to achieve ion acceleration for ion bombardment of dielectric thin films. This is achieved by rising the plasma potential (Up), in a time interval in-between the HiPIMS-pulses, using a positive reversed voltage (Urev). As long as the film surface potential (Us) is maintained low, clos...

The plasma potential at a typical substrate position is studied during the positive pulse of a bipolar high-power impulse magnetron sputtering (bipolar HiPIMS) discharge with a Cu target. The goal of the study is to identify suitable conditions for achieving ion acceleration independent on substrate grounding. We find that the time-evolution of the...

Hardness Band gap Ab-initio calculations A B S T R A C T α-(Al x Cr 1-x) 2 O 3 thin films have a wide application prospect due to their thermodynamic stable corundum structure and excellent mechanical and thermodynamic properties. In this study, theoretical investigations on the crystal structure, electronic structure, mechanical and thermodynamic...

Selective ion acceleration using a synchronized substrate bias is a common way to tailor the microstructure and intrinsic stress of films grown by high-power impulse magnetron sputtering (HiPIMS), owing to the high degree of sputtered metal ionization and the inherent time separation between different ionic species in the ion fluxes at the substrat...

Growth temperature (Ts) and ion irradiation energy (Ei) are important factors that influence film growth as well as their properties. In this study, we investigate the evolution of crystal structure and residual stress of TiNbCrAlHfN films under various Ts and Ei conditions, where the latter is mainly controlled by tuning the flux of sputtered Hf i...

The existence of a void will affect the mechanics of the polishing behavior. Therefore, this paper investigated the mechanism of ultraprecision three-body polishing of a single-crystal cubic (3C) silicon carbide workpiece with voids using molecular dynamics simulation. The effects of void size, void shape, void arrangement, and the number of voids...

Multicomponent TixNbCrAl nitride films were deposited on Si(100) substrates by reactive direct current magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) in the absence of substrate heating and bias. Three single Ti, Nb, and Cr50Al50 targets were either driven by three dc or three HiPIMS power supplies. The Ti content...

Self-lubricating Ti(C,N)-based cermets were manufactured using vacuum sintering and solid carburizing in this study, and the effects of various carbides on the carburization and wear behavior of the cermets were investigated. The findings demonstrate that solid carburizing resulted in strong graphite precipitation in all the Ti(C,N)-based matrices....

The development of cutting technologies promotes the diversification of cutting tool materials. To better guide the design and preparation of the surface films on different tools, it is necessary to explore the relationship between substrate materials and films’ properties. The TiAlN-(TiAlN/CrAlSiN)–TiAlN composite films were coated on cemented car...

The TiAlN-based composite coating was coated on TiCN-based cermets with different binder phase by arc ion plating. The effects of binder phase within cermets substrates on the microstructure, mechanical properties and wear behavior of the composite coating were investigated. The results show that the growth of the composite coating is affected by b...

Substrate materials have a significant influence on the coating properties, especially on the adhesion of coating to substrate. Therefore, the understanding of the substrate materials effect on deposited coatings will lead to a better performance of the coated cutting tools. In this investigation, the TiAlN-(TiAlN/CrAlSiN)-TiAlN multiple coatings h...

MDS (molecular dynamics simulation) was employed in this paper to study the nanometric cutting of monocrystalline silicon during the ultraprecision elliptical vibration–assisted cutting (UEVAC) process. The behavior of the workpiece during material removal by UEVAC has been studied, and the effects of different vibration frequencies, amplitude rati...

1 ，田霰 2 ，戴厚富 1 ，周彤 3 ，陈宁 3 ，胡恒宁 3 ，赵海波 4 1 贵州大学; 2 天威保变电气股份有限公司; 3 成都工具研究所有限公司； 4 四川大学 摘要：针对B8W2-3型管螺纹车刀的工况，制备了AlTiCrN和AlTiCrN-DLC涂层，分析了 复合涂层的膜层厚度、膜基结合力和摩擦磨损行为，并对涂层刀具的切削性能进行了研究， 分析了DLC膜层对涂层刀具磨损状态的影响。研究表明：AlTiCrN-DLC涂层中AlTiCrN膜层厚 度约为3.5μm；DLC膜层厚度约为2.5μm，其中DLC膜层为典型非晶态结构；AlTiCrN-DLC涂 层压痕等级为HF3，低于AlTiCrN涂层；AlTiCrN涂层摩擦系数为0.54，AlTiCrN-DLC涂层摩擦 系数为0.13，且无明...

Molecular dynamics has been employed in this paper to investigate the nanoscale cutting process of single-crystal copper with a diamond tool. The behavior of the workpiece during material removal by diamond cutting has been studied. The effects of tool geometry including rake angle, clearance angle, and edge radius are thoroughly investigated in te...

AlCr(La)N coatings were grown through mid-frequency reactive magnetron sputtering on cemented carbide (YG8) and single-crystal silicon (111) wafer. The composition, microstructure and mechanical properties of the coatings deposited under different La target currents were evaluated. The concentration of La changed from 0 at.% to 7.73 at.% displaying...

In this paper, the Ti(C,N)-based cermets with various WC contents were used as the substrates of TiAlCrN coatings. The influence of WC addition on the structures and properties of the coatings was investigated. Besides, cutting tests on the coated cermet inserts were conducted under different conditions. The results indicated that the cermet substr...

Ti(C, N)-based cermets were coated with TiAlN and TiAlN/CrAlN films by physical vapor deposition. The cross-sectional morphology was characterized by scanning electron microscopy (SEM), and the adhesive strength was evaluated by the scratch test. Cutting tests on the coated cermets were conducted on the different cutting conditions. The cutting per...

AlCrN, AlCrSiCN, AlCrSiN/MoN, and AlCrSiN/NbN coatings have been deposited on high-polished WC-Co cemented carbide substrate and tools by mid-frequency magnetron sputtering in Ar/N2 mixtures. Al0.6Cr0.4, Al0.6Cr0.3Si0.1, and C/Mo/Nb targets were used during the deposition. The microstructure and mechanical properties of as-deposited coatings were i...

TiAlMoN films with different Mo contents were deposited by magnetron sputtering at various duty ratios of sputtering Mo targets power source, after depositing a Ti interlayer. The concentrations and structure of the films were determined by energy dispersive X-ray spectroscopy, scanning electron microscopy and X-ray diffraction. The Mo content of T...

In the paper, the contributions of corrosion, erosion and synergy to the erosion–corrosion degradation of Ti(C,N)–based cermets are investigated in the different slurry conditions, and respect to the synergistic effect, corrosion enhanced erosion and erosion enhanced corrosion are also quantified. The results indicate that the contributions of corr...

The TiAlN and TiAlLaN coatings were deposited on cemented carbides (YG8) and (111) silicon wafers by using a hybrid PVD coater. The composition, microstructure, mechanical properties and oxidation resistance of the coatings deposited at different nitrogen flow rates were evaluated. The concentration of titanium decreased when the N2 gas flow was in...

In the paper, Ti(C,N)-based cermets with Cr3C2 additions were prepared, and the effects of Cr3C2 content on the erosive wear of cermets were investigated in solid–liquid erosion conditions. The results indicated that Cr3C2 addition refined the ceramic grain and improves the mechanical properties of cermets. With the variation in Cr3C2 addition up t...

The purpose of this study was to investigate the effects of Zr interlayer on the structure and mechanical properties of TiAlN films, which were deposited on the M2 high-speed steel substrates by means of plasma-enhanced magnetron sputtering. The result shows that the crystal orientation of Zr/TiAlN films is similar to that of single-layered TiAlN f...

Degradation process of Ti(C,N)-based cermet is investigated in solid-liquid erosion conditions. The results indicate that the erosion process of Ti(C,N)-based cermet is classified into incubation, development and prevalence. In the incubation stage, the weight loss is dominated by binder deterioration; in the development stage, ceramic phase and bi...

ZrAl(Y)N coatings were deposited on cemented carbide (YG8) and silicon (100) substrates by plasma-enhanced medium frequency reactive magnetron sputtering technique. The effects of yttrium addition and N2/Ar flow ratios on the composition, microstructure, mechanical properties, and oxidation resistance of ZrAl(Y)N coatings were characterized by scan...

The TiAlLaN films were deposited on YG8 and silicon (1 1 1) substrates by a hybrid PVD coater which is combined with medium frequency reactive magnetron sputtering and ion-plating evaporation. The effects of lanthanum addition and bias voltages on the composition, crystal morphology, microstructure, mechanical properties, and oxidation resistance o...

ZrAlYN films were prepared by magnetron sputtering at various N2/Ar flow ratio. The structure, composition and thermal properties were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectrum. The results show that the deposited ZrAlN and ZrAlYN films possessed a single NaCl-type solid solution phase. Th...

TiAlSiN coatings with Ti or Cr interlayers were deposited on high-speed steel using magnetron sputtering methods. The structure, crystal morphology and mechanical properties were investigated systematically. The results show that (200) is the dominant preferred orientation in Ti/TiAlSiN coating, while (111) become the predominant orientation of the...

TiAlLaN coatings were deposited on the cemented carbide substrates by mid-frequency magnetron sputtering system. The effects of Ar/N2 flow ratio on the composition, structure, adhesion and hardness followed with elastic modulus and H/E ratio were investigated systematically. Results indicate that all the Ti/Al ratios of the coatings were higher tha...

Zr/TiAlN coatings as well as single TiAlN coatings were deposited on high-speed steel and cemented carbide substrates by medium frequency magnetron sputtering. The crystal structure and cross-sectional morphology of coatings were evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The adhesion of coatings to s...

The purpose of this study is to investigate the microstructure, mechanical properties and adhesion of Ti/TiN/TiAlN and Zr/ZrN/TiAlN trilaminar coatings, which were deposited on the high-speed steel substrate and cement carbide substrate by a hybrid PVD coating technique. X-ray diffraction technique (XRD) was used to reveal the structure of coatings...

Two interlayers (Ti and Cr) have been evaluated with respect to their influence on the structure and growth of TiAlN based coatings on WC-Co cemented carbide by a non-commercial hybrid PVD (physical vapor deposition) coater by Sichuan University in China. The structure and the growth morphology were characterized by X-ray diffraction (XRD) and scan...