scholarly journals Mechanical Properties of Some Metallic Powder Alloys and Their Contribution to the Performance of Diamond Tools Used for Cutting Granite

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1219 ◽  
Author(s):  
Luís Guerra Rosa ◽  
Carlos A. Anjinho ◽  
Pedro M. Amaral ◽  
Jorge Cruz Fernandes

This work examined some pre-alloyed cobalt-, iron-, and copper-based powder binder systems—such as those launched commercially under the brand names of Cobalite and Next—in terms of their as-sintered physical-mechanical properties, namely, apparent density, Young´s modulus, yield strength, rupture strength, rupture strain, toughness modulus, and Vickers hardness. These types of sintered products are traditionally used in the fabrication of diamond impregnated tools for cutting granite stones. The following powder binder systems were evaluated: Cobalite HDR pre-alloyed powder, Next 300 pre-alloyed powder, and four other mixtures of these with Cu and Fe powders: Cobalite HDR + 20 wt% Cu; Cobalite HDR + 20 wt% Fe; Next 300 + 20 wt% Cu; Next 300 + 20 wt% Fe. The evaluation methodology aimed to establish criteria for developing new diamond tools and, therefore, it included the measurement of several technological parameters directly related to the cutting performance of the tools (e.g., energy consumption measurements made exclusively in the tool drive motor, forces generated in the tool, tool consumption per unit weight of stone removed by the cutting). The results show the adequacy of the methodology for the optimisation of diamond retention capacity of these types of metal matrices and for improving the working performance of the diamond tools.

2020 ◽  
Vol 86 (6) ◽  
pp. 62-71
Author(s):  
P. P. Sharin ◽  
S. P. Yakovleva ◽  
M. P. Akimova ◽  
V. I. Popov

The results of studying fundamental and applied problems regarding the formation of boundary layers between diamond and carbide matrix are presented with the goal to develop a highly resistant diamond tool. The new approaches to the synthesis of diamond-carbide materials combining diamond metallization and sintering in a single-stage technology are presented. The developed technology eliminates the re-heating of a metallized coatings which results in their destruction and enhanced graphitization of diamond (these phenomena restrict using metallization procedure to improve diamond retention and synthesis of high-functional composites for diamond tools). The goal of the study is analysis the structural and phase state of the «diamond – carbide matrix» interface in a diamond tool obtained by the new technology and the main factors determining the level of diamond retention in the presence of a metallized coating. Unique opportunities provided by modern high-resolution methods of research were used in the study. The elemental composition and morphological features of the diamond-matrix interface were studied using the methods of scanning electron microscopy, atomic force microscopy, X-ray microanalysis and Raman spectroscopy. Identification of the reaction products, including non-diamond carbon was performed. It is shown that the introduction of the powder-metallizer significantly modified the contact boundaries and provide conditions for improving the chemical and mechanical adhesion of the diamond-matrix system. The formation of the well-developed nano- and sub-microscale roughness of the diamond surface and dense filling of the existing voids with nanoscale layers of metal-infiltrate was revealed. The multilevel organization of highly structured elements of the transition zone with the minimal graphitization ensured the monolithic character and strength of the diamond-matrix bond. Comparative service tests of preproduction and control samples of diamond dressers proved the efficiency of developed hybrid technology (the specific performance of diamond tools increased by 39 – 45%). New fundamental and applied results have been obtained in the field of studying interface zones in crystalline multiphase systems that can be used to regulate adhesion phenomena at the interphase boundaries and develop highly efficient composite materials.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3755
Author(s):  
Štefan Gašpár ◽  
Tomáš Coranič ◽  
Ján Majerník ◽  
Jozef Husár ◽  
Lucia Knapčíková ◽  
...  

The resulting quality of castings indicates the correlation of the design of the mold inlet system and the setting of technological parameters of casting. In this study, the influence of design solutions of the inlet system in a pressure mold on the properties of Al-Si castings was analyzed by computer modelling and subsequently verified experimentally. In the process of computer simulation, the design solutions of the inlet system, the mode of filling the mold depending on the formation of the casting and the homogeneity of the casting represented by the formation of shrinkages were assessed. In the experimental part, homogeneity was monitored by X-ray analysis by evaluating the integrity of the casting and the presence of pores. Mechanical properties such as permanent deformation and surface hardness of castings were determined experimentally, depending on the height of the inlet notch. The height of the inlet notch has been shown to be a key factor, significantly influencing the properties of the die-cast parts and influencing the speed and filling mode of the mold cavity. At the same time, a significant correlation between porosity and mechanical properties of castings is demonstrated. With the increasing share of porosity, the values of permanent deformation of castings increased. It is shown that the surface hardness of castings does not depend on the integrity of the castings but on the degree of subcooling of the melt in contact with the mold and the formation of a fine-grained structure in the peripheral zones of the casting.


2020 ◽  
Vol 17 ◽  
pp. 00094
Author(s):  
Dmitry N. Byshov ◽  
Irina A. Petunina ◽  
Elena A. Kotelevskaya ◽  
Sergey N. Borychev ◽  
Georgy K. Rembalovich

The paper presents a method to substantiate the technical and technological parameters of the device to sort corn cobs, which takes into account the biometric and physical-mechanical properties of the treated plant objects. The method of basic parameters substantiation involves determining the overall dimensions of the device, the geometric and technological parameters of the working bodies, as well as the energy for operation.


2007 ◽  
Vol 23 ◽  
pp. 123-126
Author(s):  
Radu L. Orban ◽  
Mariana Lucaci

This paper investigates the effect of Fe, Cr and B additions, in small proportions, as alloying elements in Ni3Al with the purpose to reduce its intrinsic fragility and extrinsic embrittlement and to enhance, in the same time, its mechanical properties. It represents a development of some previous research works of the authors, proving that Ni3Al-Fe-Cr-B alloys obtained by reactive synthesis (SHS) starting from Mechanically Alloyed powder mixtures have superior both room temperature tensile strength and ductility, and compression ones at temperatures up to 800 °C, than pure Ni3Al. These create premises for their using as superalloys substitutes.


2021 ◽  
Vol 890 ◽  
pp. 120-137
Author(s):  
Mihai Octavian Crăcănel ◽  
Eduard Laurențiu Niţu ◽  
Daniela Monica Iordache

The FSW process has proven to be a promising process for joining steels and improving their characteristics. However, the use of wrongs technological parameters leads to the appearance of defects. In this study, the macro and microstructural characteristics of steel joints and their mechanical properties are analyzed, and the main types of defects of the butt steel joints are presented. The main conclusions of the works studied are summarized and the main development directions for research on the characterization of steel structures joined by the FSW process are identified.


2019 ◽  
pp. 7-8
Author(s):  
M. M. Egorov ◽  
V. I. Milov ◽  
M. K. Timin ◽  
T. P. Mukhina ◽  
V. S. Smirnov ◽  
...  

The effect of pressure, temperature and time during direct pressing on the strength and optical characteristics of adhesive plasticized polyvinyl butyral films is studied. A mathematical analysis of the results of a full factorial experiment is carried out and the regression equations are derived.


2020 ◽  
pp. 451-457
Author(s):  
Aleksandr Yur'yevich Vititnev ◽  
Yuriy Davydovich Alashkevich ◽  
Natal'ya Geral'dovna Chistova ◽  
Roman Aleksandrovich Marchenko ◽  
Venera Nurullovna Matygullina

This paper presents the results of experimental studies of the physical and mechanical properties of wood-fiber boards of the wet production method when regulating the design and technological parameters of the grinding process. This allowed us to determine the influence of the working clearance between the grinding discs and the concentration of fibre mass with the subject to of quality change wood fiber after defibrator using the developed construction of the disc fibrillation action on the physico-mechanical properties of boards. As a result of the experiment, regression models were obtained that adequately describe the studied grinding process and allow predicting the values of physical and mechanical properties of the finished product depending on the established  parameters process. A comparative analysis of the size and quality characteristics of the fiber semi-finished product and its fractional composition when using a developed construction the disc of refiner fibrillation action and a traditional design used in industry is carried out. The preferential efficiency of the grinding process under the fibrillating effect the disc of refiner in comparison with the traditional construction disc of refiner is established. As a result, there is a significant improvement in the quality indicators of the fiber semi-finished product and its composition due to the formation and predominance in the total mass of long and thin, respectively, flexible fibrillated fibers with high tile-forming properties, which allows to increase the strength properties of the product (by 20–25%), without using binding resins.


Academia Open ◽  
2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Khasanov Doston

The wide possibilities of modifying manufactured industrial fibers aimed at improving their physico-mechanical properties, structural and technological parameters. In connection with the above, it was of interest to study the effect of a number of water-soluble compositions based on a poly-quaternary salt of dimethyl-allyl-β - methacryloyloxyethylammonium bromide in combination with glycerin on the structural and physico-mechanical properties of protein fiber, and also to study the effect of the composition on wool spinning and the quality of wool yarn .


2020 ◽  
Vol 8 (6) ◽  
pp. 2565-2570

Today, the production of knitwear is developing at a faster pace. In industry, trade and the service sector, the production of knitwear, combining high technology and low cost, with good consumer properties is urgently required. Consumers today are looking for comfort, fashion and style, which results in ever-changing demands on the apparel market. As the consumer’s requirements to quality and appearance of product are daily increasing, the attention to the question of replacement of a smooth cloth on wide assortment with pattern effect is sharply brought. This work deals with the analysis of technological parameters and physical-mechanical properties of the knit fabric with pattern effect. With the aim of to expand the assortments of knitwear and to use the technological capabilities of double-bed flat knitting machines in fullest extent possible, on the base of rib structure, by using of loop transference 2 new variants of combined structure were developed and recommended. Samples differ from each other by the rapport and pattern effect of the knit structure. Technological parameters, such as loop length, stitch density, surface and volume density, physical-mechanical properties, such as breaking strength and elongation of newly developed combined knit structures were also determined by experimental method. Loop length and stitch density are important variables, that by changing them, the surface and volume density can be changed, that can manage the raw material consumption and determine the quality of knit fabrics. Breaking strength and elongation are important and decisive parameters for end uses since low strength properties shorten the useful life time as well disable the functionality of these products. Patterns of influence of structural elements, such as transferred loops on the surface density and volume density of knitwear was established. It is found that offered structures have some advantages to compare to basic structure. On the aim of resource economy technology, they give a possibility of raw material expenditure decreasing 22-47%.


Author(s):  
Alsaid Mazen ◽  
Ali Salamekh

In the last decades there is increasing the need to apply polymer composite materials in different industries, particularly in shipbuilding. There are developing single structures made from polymer composite materials to be used on board ships. The article focuses on technology of manufacturing slabs from polymer composite materials to carry out mechanical testing in the laboratory special standard units. Mechanical properties of polymer composite materials depend on molding technologies. There has been described a technology of sample manufacturing from polymer composite materials reinforced with glass fiber mat with fiberglass plastics. The technique of testing the specified samples for tensile strength has been considered. The sizes and shapes of the samples as well as the technological parameters of the manufacturing process have been validated, depending on the standard requirements and the technological features of the testing machine. The physical and mechanical properties of the components that make up the composite materials are considered. The sequence of stacking layers for preparation of plates from composite materials is indicated. The dimensions of the plates for cutting out finished samples are determined, depending on the method of production. The way of laying plates from composite materials has been chosen on the base of economic considerations and conditions of accessibility. The obtained results of mechanical properties can be used in solving problems of application of polymer composite materials in shipbuilding, for example, in manufacturing superstructures of some dry cargo vessels.


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