- TITLE:
INFLUENCE OF SINTERING TEMPERATURE ON THE STRENGTH PROPERTIES OF THE POWDER STRUCTURAL MATERIAL FROM THE SYSTEM FE-C-P
- AUTHOR(S):
I. Mitev, I. Todorova
- ABSTRACT:
In the present study the influence of phosphorus over the strength characteristics of the powder construction materials of triple system Fe-С-Р is detected. Research samples are subjected to a base iron powder type - ASC 100.29. To the iron matrix 0,2÷1,0%C and 0,3÷0,45%Р is added. Pressing is carried out with the effort of 600MPa and sintering is conducted at 950÷1250ºС for 30 min at a protective environment
of dissociated ammonia. The density of the samples after sintering is in the range 7,10÷7,12g/cm 3. In tables and graphics are presented experimental results for tensile strength, yield strength and elongation.
- TITLE:
REALIZATION OF FRAME-CONFIGURATIONS CONCEPTION OF MACHINE-TOOLS WITH MECHANISMS PARALLEL STRUCTURE
- AUTHOR(S):
Y. N. Kuznetsov, D. A. Dmitriev
- ABSTRACT:
The realization of machine-tools with parallel structure mechanisms frame-configurations conception is shown. Principles and laws of formation of less metal-consumption layouts of multifunctional processing equipment are formulated. Design procedure of the proposed structural formulas is defined. Techniques to perform directed search and design of new machinery, which corresponds to the high level technological purpose proposed and tested. The machine-tools samples implemented on the principles of the conception.
- TITLE:
EXPERIMENTAL RESEARCH OF HYDRODYNAMICS OF FLOWS WITH A VARIABLE ALONG THE LENGTH MASS
- AUTHOR(S):
S. Serhiy, D. Kolesnikov, O. Yakhno
- ABSTRACT:
The paper analyzes the results of experiments on the research of the flow of viscous fluids in nozzles in the presence of discrete selection. The results of the experiments confirmed the assumption that the flow is not stabilized, i.e. there are inertia forces from convective acceleration except viscous friction forces. Conclusions about the impact of the curvilinear pipeline on the hydraulic losses are made. Using the results of the research, the recommendations for the design of nozzles and sprinklers with the same loss coefficients are offered.
- TITLE:
INCREASE OF STABILITY OF GEOMETRICAL DIMENSIONS OF HOLES ACQUIRED BY IMPULSE HYDROABRASIVE BROACHING
- AUTHOR(S):
Y. Pavluchenko, M. Khorolska, M. Yatsyna, O. Salenko
- ABSTRACT:
The paper presents the results of researches of efficiency of processes hydroabrasive broaching of the holes with the means of copying method and it has been shown that the use of traditional means for this technology is extremely energy inefficient. It is noted that power losses are defined by the fact that in the hydraulic system the multiple conversions of energyoccur, in the result of which mechanical work of
the actuator is converted into kinetic energy of the flow stream. However, excessive power losses are caused by cyclical execution of the holes, as the time for the positioning and deployment of the automation systems of the jet exceeds the operating time (in the case perforating of the protective screens for turbine-driven generators does not exceed 0.5 sec.). The analysis of operation of typical hydraulic unit of
hydrocutting machine was being held, the results of measurements of power losses in the individual circuits are given. There were suggested to determine the energy efficiency of the process with the corresponding coefficient, taking into account not only the energy parameters but the cyclic operation of the device. There was proposed the working principle of the hydraulic system in which the energy losses will be minimized by appropriate control of the main pump.
- TITLE:
IMPROVING THE EFFICIENCY OF WATERJET PROCESSING DUE TO THE EFFECT OF INITIATED CRACKING
- AUTHOR(S):
V.N. Orel, A.F. Salenko, V.T Shchetynin, O.O. Chencheva
- ABSTRACT:
The paper discusses the issues of providing quality and reliability of waterjet treatment while increasing process productivity with the use of the effect of initiated cracking. It is shown that the creation of a certain cyclic stress state of the workpiece end allows to call the phenomenon of cracking with active cracks bifurcation in which originated on microdefects and adhesion surfaces cracks do not have time to develop into a trunk. Weak destructive area is treated with much less energy, but a violation of process conditions can lead to the spread of the destructive material zone beyond the area of destruction, thereby processing will be defective.
