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The investigation of microstructure and hardness of archaeological alloys  [PDF]
J. Konieczny,?. Kondzio?ka,I. M?odkowska-Przepiórowska
Journal of Achievements in Materials and Manufacturing Engineering , 2011,
Abstract: Purpose: The aim of the work was to investigate the microstructure and hardness of archaeological metal.Design/methodology/approach: The investigations of the microstructure were made on ZEISS SUPRA 25 with EDX method. Investigation of structure were made on PANalytical’s X’Pert diffractometer.Findings: Metallographic studies were carried out on archeological finds that have been extracted from the ground during excavations on the market in Czestochowa (Poland) during the summer of 2009. In addition to the remains of buildings discovered under the level of market research objects were excavated in the area. Preliminary dating of the material shows a broad interval.Research limitations/implications: In the examined finds the main component is copper, but they also contain other elements, sometimes in large numbers, that indicates a very low-purity metallurgical material and thus proves that this is not a typical bronze how manufactured at that time. The metal nails are characterized by high purity metallurgical.Practical implications: The presented results are an important contribution to the accurate characterization of found objects and also can help to determine more accurately determine their age and use in daily life of ancestors.Originality/value: These factors indicate new areas of research in materials science that significantly enrich the knowledge of times past.
Nanoindentation Study on Tourmaline  [PDF]
M.O. Adeoye, O.O. Adewoye
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2006, DOI: 10.4236/jmmce.2006.51004
Abstract: Nanoindentation tests were performed on the basal (0001) and prismatic (10ī0) surfaces of tourmaline crystals. These results were used along with Vickers microhardness tests to investigate the hardness of the material on these surfaces at different load regimes. It was found that the (0001) surface indicated a higher hardness at ultra-low loads while (10ī0) becomes the harder plane at higher loads. Evidence of plastic deformation at room temperature in the otherwise very brittle (ceramic) material was also established, and the elastic modulus was determined.
Surface roughness investigation and hardness by burnishing on titanium alloy  [PDF]
S. Thamizhmnaii,B. Bin Omar,S. Saparudin,S. Hasan
Journal of Achievements in Materials and Manufacturing Engineering , 2008,
Abstract: Purpose: Burnishing is a chip less machining process in which a rotating roller or ball is pressed against metal piece. It is a cold working process and involves plastic deformation under cold working conditions by pressing hard. The burnishing process help to improve surface roughness and hardness.Design/methodology/approach: The methodology adopted was using a multi roller on square titanium alloy material by designing various sliding speed/ spindle speed, feed rate and depth of penetration.Findings: The roller burnishing is very useful process to improve upon surface roughness and hardness and can be employed. It will help to impart compressive stress and fatigue life can be improved. The titanium alloy is a difficult to machine material and burnishing is difficult process for this grade material. A low surface roughness and high hardness was obtained for the same spindle rotation, feed rate and depth of penetration.Research limitations/implications: There are some limitations in increasing the operating parameters. It may develop flaw and micro cracks on the surface.Originality/value: The value of the work lies in using the results for other researches to follow and further can be continued on fatigue life.
Observation of spontaneous polarization of tourmaline
Observation of spontaeous Polarization of tourmaline

Jin Zong-Zhe,Ji Zhi-Jiang,Liang Jin-Sheng,Wang Jing,Sui Tong-Bo,
金宗哲
,冀志江,梁金生,王静,隋同波

中国物理 B , 2003,
Abstract: Since Tetsujiro Kubo indirectly found the spontaneous polarization of tourmaline through absorbing copper ions in copper sulfate aqueous solutions in 1980s, there is no other evidence to demonstrate the existence of the spontaneous polarization in tourmaline. It was found that after a tourmaline particle was bombarded by electron beams, a spot appeared on the surface of the sample, and that one half of the spot was brighter than the other half under scanning electron microscope. After tourmaline was treated for 2 h at 1223K and then bombarded by electron beams, the bombardment spot did not appear because the crystal structure of tourmaline is destroyed. The existence of the bombardment spot accounts for the spontaneous polarization. The shape and brightness of the bombardment spot not only shows the existence of a surface electric field induced by spontaneous polarization, but also the relation with the direction of the crystal plane of tourmaline.
INVESTIGATION ON DEPOSITIONS AND HARDNESS CHARACTERISTICS OF a SiC:H FILMS
INVESTIGATION ON DEPOSITIONS AND HARDNESS CHARACTERISTICS OF a-SiC:H FILMS

XFRong,ZYQin College of Mechanical Engineering,Taiyuan University of Technology,Taiyuan,China,
X.F.Rong and Z.Y.Qin College of Mechanical Engineering
,Taiyuan University of Technology,Taiyuan,China

金属学报(英文版) , 1999,
Abstract: In this paper, a deposition feature of a SiC:H films deposited by a RF sputtering system and a effect on the hardness of the films with various deposition conditions are investigated, and the effects of the silicon on a C:H are studied. It follows from the results that the properties of hardness can be changed with the depositing conditions. An increase of silane in the gas phase allows to deposit a SiC:H having tetrahedral structure. The sets of deposition conditions by which the different types of a SiC:H films can be deposited are obtained.
Hardness of FeB4: Density functional theory investigation  [PDF]
Miao Zhang,Mingchun Lu,Yonghui Du,Lili Gao,Cheng Lu,Hanyu Liu
Physics , 2013, DOI: 10.1063/1.4871627
Abstract: A recent experimental study reported the successful synthesis of an orthorhombic FeB4 with a high hardness of 62 GPa, which has reignited extensive interests on whether transition metal borides (TRBs) compounds will become superhard materials. However, it is contradicted with some theoretical studies suggesting transition metal boron compounds are unlikely to become superhard materials. Here, we examined structural and electronic properties of FeB4 using density functional theory. The electronic calculations show the good metallicity and covalent FeB bonding. Meanwhile, we extensively investigated stress strain relations of FeB4 under various tensile and shear loading directions. The calculated weakest tensile and shear stresses are 40 GPa and 25 GPa, respectively. Further simulations (e.g. electron localized function and bond length along the weakest loading direction) on FeB4 show the weak Fe-B bonding is responsible for this low hardness. Moreover, these results are consistent with the value of Vickers hardness (11.7 to 32.3 GPa) by employing different empirical hardness models and below the superhardness threshold of 40 GPa. Our current results suggest FeB4 is a hard material and unlikely to become superhard.
Influence of Polar Tourmaline Substrates on the Growth of ZnO Nanoplates
GUO Yun, XIA Yi-Ben, MIN Jia-Hua, ZHAO Yue, WANG Bin
无机材料学报 , 2010, DOI: 10.3724/sp.j.1077.2010.00717
Abstract: Nanoplate-shaped ZnO thin film was achieved by the ultrasonic spray pyrolysis technique, using polar (0001) tourmaline wafers as the growing substrates. The as-prepared nanoplates were cross-linked and upright- standing. XRD and Raman tests revealed the hexagonal structure of wurtzite. The electron probe microanalysis and M?ssbauer spectroscope were utilized to explore the chemical composition and the fine structures of Fe ions in tourmaline substrates. The plate-like growth of ZnO nanocrystals are related to the surface electric field effect of tourmaline crystals. With the variation of Fe ions contents, valence states and occupation characters, the ratio of thickness to diameter of the ZnO nanoplates decreases with the increase of the intrinsic dipole moments along the c axis and the strengthening of surface electric field effect in tourmaline crystals.
Investigation on the Change Effected by the Tool Type on the Hardness of Friction Stir Processed AA6063 Aluminium Alloy  [PDF]
D. Peter Pushpanathan,K. Ganesa Balamurugan,K. Mahadevan
Journal of Applied Sciences , 2012,
Abstract: Aluminium alloy 6063 is one of the most popular alloys in the 6000 series which provides good extrudability and surface finish. Various application of this alloy include architectural and building products, electrical components and conduit, pipes for irrigation systems, door and window frames, railings and furniture, etc. However improving its strength by improving the hardness would complement the existing advantages of this alloy. This study was intended to improve the hardness of this alloy by FSP (friction stir processing) technique. The effect of two tool types on the hardness of the friction stir processed surfaces was studied. It was found that the hardness values of the friction stir processed surfaces varied between the tool types. The surfaces processed with both tool types show considerable improvement in the hardness when compared to the hardness of the unprocessed bulk material. Experiments were conducted as per full factorial 23 design of experiment with various process parameter combinations for both tools.
The Ti-influence on the tourmaline color
Fonseca-Zang, Warde A. da;Zang, Joachim W.;Hofmeister, Wolfgang;
Journal of the Brazilian Chemical Society , 2008, DOI: 10.1590/S0103-50532008000600020
Abstract: titanium was examined in different black tourmalines by spectrophotometric analyses in the region between 12500 and 27000 cm-1 (800-370 nm) using a microscope spectrophotometer mpv-5p, leitz (germany), and chemically analyzed on an electron microprobe camebax microbeam, cameca (france) in wds mode. fourteen tourmaline samples with their face oriented parallel to the principal axis, cut and polished down to thin sections, showed polarized spectra of two broad absorption bands at approximately 14000 cm-1 (715 nm) and 24000 cm-1 (417 nm). precision thickness measurements were used to calculate the absorption coefficients α. for the absorption around 24000 cm-1, a linear correlation was observed between α and the tio2 content (mass %). another linear regression was observed between α and the product of tio2 and feo (%) contents. cations located in the y- and z-octahedrons of the structure that are connected over edges might contribute to intervalence charge transfer transitions (ivct) between ti3+-ti4+, fe2+-ti4+ and ti3+-ti4+-fe3+.
Monte Carlo investigation of the magnetic anisotropy in Fe/Dy multilayers  [PDF]
Etienne Talbot,Pierre Emmanuel Berche,Denis Ledue
Physics , 2008, DOI: 10.1016/j.jmmm.2008.06.032
Abstract: By Monte Carlo simulations in the canonical ensemble, we have studied the magnetic anisotropy in Fe/Dy amorphous multilayers. This work has been motivated by experimental results which show a clear correlation between the magnetic perpendicular anisotropy and the substrate temperature during elaboration of the samples. Our aim is to relate macroscopic magnetic properties of the multilayers to their structure, more precisely their concentration profile. Our model is based on concentration dependent exchange interactions and spin values, on random magnetic anisotropy and on the existence of locally ordered clusters that leads to a perpendicular magnetisation. Our results evidence that a compensation point occurs in the case of an abrupt concentration profile. Moreover, an increase of the noncollinearity of the atomic moments has been evidenced when the Dy anisotropy constant value grows. We have also shown the existence of inhomogeneous magnetisation profiles along the samples which are related to the concentration profiles.
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