scholarly journals Comprehensive Research and Analysis of a Coated Machining Tool with a New TiAlN Composite Microlayer Using Magnetron Sputtering

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3633
Author(s):  
Štefan Michna ◽  
Iryna Hren ◽  
Jan Novotný ◽  
Lenka Michnová ◽  
Václav Švorčík

The application of thin monolayers helps to increase the endurance of a cutting tool during the drilling process. One such trendy coating is TiAlN, which guarantees high wear resistance and helps to “smooth out” surface defects. For this reason, a new type of weak TiAlN microlayer with a new composition has been developed and applied using the HIPIMs magnetron sputtering method. The aim of this study was to analyze surface-applied micro coatings, including chemical composition (EDX) and microstructure in the area of the coatings. Microstructural characterization and visualization of the surface structures of the TiAlN layer were performed using atomic force microscopy. To study the surface layer of the coatings, metallographic cross-sectional samples were prepared and monitored using light and electron microscopy methods. The microhardness of the test layer was also determined. Analyses have shown that a 2-to-4-micron thick monolayer has a microhardness of about 2500 HV, which can help increase the life of cutting tools.

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 119
Author(s):  
Jan Novotny ◽  
Stefan Michna ◽  
Iryna Hren ◽  
Jaromir Cais ◽  
Irena Lysonkova ◽  
...  

The basic prerequisite for obtaining the coating of good quality is the production of a layer without the occurrence of surface defects. A possible solution to the occurrence of defects on the functional surface of the form is the application of a polytetrafluoroethylene (PTFE)-based coating. The coating helps to reduce surface roughness and “smooth” defects like pores and micro-shrinkage. For this reason, a new type and methodology of the coating were prepared to achieve more production cycles between the individual cleaning processes during the production of a tire. The subject of the study was the analysis of surface-applied micro-coatings, including the analysis of chemical composition by using energy-dispersive X-ray (EDX) and microstructure in the area of coatings. Detailed microstructural characterization of Alfipas 7818 and Alfiflon 39 and its imaging of surface structures were studied using atomic force microscopy. To examine the surface layer of the coatings, metallographic specimens of cross-sections (by means of a mold) were prepared and examined by light and electron microscopy. This new multilayer micro-coating with a thickness of 20–25 μm has been found to prevent form contamination during tire production and to extend production cycles by 200–400% between process cleanings. This finding was actually tested in the production of tires in the environment of a large manufacturing company.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 854
Author(s):  
Muhammad Aamir ◽  
Khaled Giasin ◽  
Majid Tolouei-Rad ◽  
Israr Ud Din ◽  
Muhammad Imran Hanif ◽  
...  

Drilling is an important machining process in various manufacturing industries. High-quality holes are possible with the proper selection of tools and cutting parameters. This study investigates the effect of spindle speed, feed rate, and drill diameter on the generated thrust force, the formation of chips, post-machining tool condition, and hole quality. The hole surface defects and the top and bottom edge conditions were also investigated using scan electron microscopy. The drilling tests were carried out on AA2024-T3 alloy under a dry drilling environment using 6 and 10 mm uncoated carbide tools. Analysis of Variance was employed to further evaluate the influence of the input parameters on the analysed outputs. The results show that the thrust force was highly influenced by feed rate and drill size. The high spindle speed resulted in higher surface roughness, while the increase in the feed rate produced more burrs around the edges of the holes. Additionally, the burrs formed at the exit side of holes were larger than those formed at the entry side. The high drill size resulted in greater chip thickness and an increased built-up edge on the cutting tools.


Author(s):  
I Hren ◽  
S Michna ◽  
J Svobodova ◽  
L Michnova ◽  
L Benes

The basic prerequisite for obtaining a quality casting according to the requirements and specifics of the customer is the production of the mould (in our case using low-pressure die-casting) without the occurrence of surface defects in the form of cracks, scabs, microshrinkages and local depressions. In this case, the mould segments for the tyre production are those which show tiny cracks or scabs on the functional surface of the castings that define the surface quality of the resulting product. It is necessary to analyse these defects in order to eliminate the causes of their formation in the casting process. For this reason, a new alloy of eutectic silumin AlSi9 alloyed with Mg, Mn and modified Sr was prepared in order to improve the fluidity and maintain the mechanical properties of the material up to 250 ℃ The subject of the study was the analysis of the surface defects of the mould, including the analysis of the chemical composition (energy-dispersive X-ray) and microstructure in the defect area. In order to investigate the subsurface layer of defects, metallographic specimens of cross-sections were prepared by means of mould, which were examined by light and electron microscopy. The detailed microstructural characterization of individual elements was performed on lamellas of the mould studied using transmission electron microscopy. An X-ray diffraction analysis was performed to investigate the residual stress at the defects area very closely. It has been found that a smaller number of defects on the functional surfaces can be obtained by changing the mould position during casting.


Author(s):  
Masaaki Sugiyama ◽  
Hiroshi Kubo ◽  
Kurio Fukushima

Superconducting cryo-electron microscope (SCM) has been mainly applied to the biological field, due to the advantages such as reduction of radiation damage and the possibility of a perfectly contamination-free environment. From the material science view point, microstructural characterization at liquid helium temperature is an attractive technique. In this presentation, some topics concerning the low temperature physics of ceramics will be discussed on the basis of the data obtained using high resolution SCM.The principle of the superconducting lens (SCL) was first described by the Dietrich Group of Siemens AG, West Germany in 1966, following this by fitting a SCL as the objective lens of a 200kV electron microscope, a new type of electron microscope, the JEM-2000SCM, was developed by JEOL LTD, Japan. A detailed cross-sectional diagram of the SCL is shown in Fig.1. A spherical aberration coefficient of 1.2mm was obtained.


2014 ◽  
Vol 895 ◽  
pp. 12-16
Author(s):  
S. Najwa ◽  
Ahmad Shuhaimi ◽  
N. Ameera ◽  
K.M. Hakim ◽  
M. Sobri ◽  
...  

Indium tin oxide (ITO) nanocolumns were successfully deposited on both glass and silicon substrates at different substrate temperature from room temperature to 300°C by radio frequency (RF) magnetron sputtering system using an ITO target. The composition of the ITO target was 90% indium oxide and 10% tin oxide. Structures and morphological properties of ITO nanocolumns were investigated. X-ray diffraction (XRD) measurement revealed that the main preferred orientation was changed from (222) to (400) as the substrate temperature increased. The atomic force microscopy (AFM) reveals that the roughness values were increases as the substrate temperature increases. The cross sectional and top view field emission scanning electron microscopy (FESEM) images show that densely packed nanocolumn arrays were obtained from all the samples.


1992 ◽  
Vol 280 ◽  
Author(s):  
M. P. de Boer ◽  
J. E. Angelo ◽  
A. M. Dabiran ◽  
P. I. Cohen ◽  
W. W. Gerberich

ABSTRACTAtomic Force Microscopy (AFM) images are correlated with Transmission Electron Microscopy (TEM) plan-view images in a structure consisting of <111> oriented GaAs layers grown by molecular beam epitaxy (MBE) at 500°C. We present results on the applicability of AFM, which requires short sample preparation and imaging time relative to TEM, in obtaining information on twin density and growth pits of these low temperature samples. Also, we discuss the behavior of twin boundaries by comparing plan-views and cross sectional TEM images.


Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.


1999 ◽  
Vol 577 ◽  
Author(s):  
A. Gavrin ◽  
C. Sellers ◽  
S.H. Liouw

ABSTRACTWe have used Magnetic Force Microscopy (MFM) to study the magnetic domain structures of melt-spun Nd-Fe-B ribbons. The ribbons are commercial products (Magnequench International, Inc. MQP-B and MQP-B+) with a thickness of approximately 20 microns. These materials have identical composition, Nd12.18B5.36Fe76.99Co5.46, but differ in quenching conditions. In order to study the distribution of domain sizes through the ribbon thickness, we have prepared cross-sectional samples in epoxy mounts. In order to avoid artifacts due to tip-sample interactions, we have used high coercivity CoPt coated MFM tips. Our studies show domain sizes typically ranging from 50-200 nm in diameter. This is in agreement with studies of similar materials in which domains were investigated in the plane of the ribbon. We also find that these products differ substantially in mean domain size and in the uniformity of the domain sizes as measured across the ribbon. While the B+ material shows nearly uniform domain sizes throughout the cross section, the B material shows considerably larger domains on one surface, followed by a region in which the domains are smaller than average. This structure is presumably due to the differing quench conditions. The region of coarse domains varies in thickness, disappearing in some areas, and reaching a maximum thickness of 2.75 µm in others. We also describe bulk magnetic measurements, and suggest that.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 826
Author(s):  
Muhammad Waqas Qureshi ◽  
Xinxin Ma ◽  
Guangze Tang ◽  
Bin Miao ◽  
Junbo Niu

The high-power impulse magnetron sputtering (HiPIMS) technique is widely used owing to the high degree of ionization and the ability to synthesize high-quality coatings with a dense structure and smooth morphology. However, limited efforts have been made in the deposition of MAX phase coatings through HiPIMS compared with direct current magnetron sputtering (DCMS), and tailoring of the coatings’ properties by process parameters such as pulse width and frequency is lacking. In this study, the Cr2AlC MAX phase coatings are deposited through HiPIMS on network structured TiBw/Ti6Al4V composite. A comparative study was made to investigate the effect of average power by varying frequency (1.2–1.6 kHz) and pulse width (20–60 μs) on the deposition rate, microstructure, crystal orientation, and current waveforms of Cr2AlC MAX phase coatings. X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to characterize the deposited coatings. The influence of pulse width was more profound than the frequency in increasing the average power of HiPIMS. The XRD results showed that ex situ annealing converted amorphous Cr-Al-C coatings into polycrystalline Cr2AlC MAX phase. It was noticed that the deposition rate, gas temperature, and roughness of Cr2AlC coatings depend on the average power, and the deposition rate increased from 16.5 to 56.3 nm/min. Moreover, the Cr2AlC MAX phase coatings produced by HiPIMS exhibits the improved hardness and modulus of 19.7 GPa and 286 GPa, with excellent fracture toughness and wear resistance because of dense and column-free morphology as the main characteristic.


1994 ◽  
Vol 339 ◽  
Author(s):  
R. Turan ◽  
Q. Wahab ◽  
L. Hultman ◽  
M. Willander ◽  
J. -E. Sundgren

ABSTRACTWe report the fabrication and the characterization of Metal Oxide Semiconductor (MOS) structure fabricated on thermally oxidized 3C-SiC grown by reactive magnetron sputtering. The structure and the composition of the SiO2 layer was studied by cross-sectional transmission electron microscopy (XTEM) Auger electron spectroscopy (AES). Homogeneous stoichiometric SiO2 layers formed with a well-defined interface to the faceted SiC(lll) top surface. Electrical properties of the MOS capacitor have been analyzed by employing the capacitance and conductance techniques. C-V curves shows the accumulation, depletion and deep depletion phases. The capacitance in the inversion regime is not saturated, as usually observed for wide-bandgap materials. The unintentional doping concentration determined from the 1/C2 curve was found to be as low as 2.8 × 1015 cm-3. The density of positive charges in the grown oxide and the interface states have been extracted by using high-frequency C-V and conductance techniques. The interface state density has been found to be in the order of 1011cm2-eV-1.


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