The method of calculation of the deviation of the tool axis when machining small diameter holes

2020 ◽  
pp. 24-30
Author(s):  
A.V. Zaytsev ◽  
N. A. Kolupaev

The article is devoted to an important parameter that characterizes the accuracy of the shape and location of the hole after machining — the displacement of the hole axis. When designing operations for drilling small-diameter holes with a large depth (the ratio of the hole depth to its diameter is more than 10), a method for predicting this parameter is necessary to improve the accuracy of work. The article considers the causes and methods of eliminating this negative impact on hole machining using the example of a small-diameter drill axis runout. Recommendations are given for reducing drill runout: to reduce cutting modes; to perform the drilling operation while rotating the workpiece, which can stabilize the drill position during machining; to use drills made of hard alloy or obtained by powder metallurgy methods, which increases their rigidity; before drilling the workpiece, to center the hole with a more rigid drill.

Alloy Digest ◽  
2017 ◽  
Vol 66 (2) ◽  

Abstract Böhler (or Boehler) S692 Microclean is a high sulfur, high carbon PM M4, with higher manganese and 0.22 sulfur for improved machining characteristics, and is available in rounds greater than or equal to 64.16 mm (2.562 in.) diameter. S693 Microclean is the low sulfur version of high carbon PM M4, available in flats and small diameter rounds. PM refers to powder metallurgy. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on surface qualities as well as heat treating and powder metal forms. Filing Code: TS-739. Producer or source: Böhler Edelstahl GmbH & Company KG.


2021 ◽  
Vol 1942 (1) ◽  
pp. 012019
Author(s):  
A G Gnedovets ◽  
V A Zelensky ◽  
A B Ankudinov ◽  
V S Shustov ◽  
M I Alymov

2019 ◽  
Vol 484 (4) ◽  
pp. 436-440
Author(s):  
A. G. Gnedovets ◽  
V. A. Zelenskii ◽  
A. B. Ankudinov ◽  
M. I. Alymov

This paper reports on the creation of a highly porous material with a hierarchical structure using powder metallurgy methods based on nickel nanopowder and ammonium bicarbonate NH4HCO3 as a space holder.


2021 ◽  
pp. 12-20
Author(s):  
A.V. Shestakov ◽  
◽  
M.M. Karashaev ◽  
N.S. Dmitriev ◽  
◽  
...  

The article discusses the main technological approaches to obtain heat-resistant and heat-resistant materials based on compounds in the Ni–Al system in order to use them in promising products of aviation and rocket technology. It is shown that when receiving materials based on compounds in the Ni-Al system, a phase of eutectic origin is formed based on the Ni3Al compound, which reduces the technological plasticity of the alloys of this system. The use of powder metallurgy methods eliminates such phases in the structure of alloys obtained using granule metallurgy technology, as well as with the use of special methods of powder metallurgy. Technological approaches are presented to obtain similar materials using powder metallurgy methods combined with thermomechanical processing.


2020 ◽  
pp. 100739 ◽  
Author(s):  
Soroush Parvizi ◽  
Seyed Mahdi Hashemi ◽  
Fatemeh Asgarinia ◽  
Mohammadreza Nematollahi ◽  
Mohammad Elahinia

2012 ◽  
Vol 565 ◽  
pp. 376-381 ◽  
Author(s):  
Yoshiyuki Masuta ◽  
Koichi Okuda ◽  
Hiroo Shizuka ◽  
Masayuki Nunobiki

This paper describes an influence of the cutting condition on the tool performance and the hole shape accuracy in a deep-hole machining of stainless steel with small-diameter drill. The drilling tests were carried out by changing the feed, tool diameter and drill length in order to investigate the appropriate cutting conditions for drilling the holes with deep depth. The results indicate that the increase of the thrust force leads to the buckling of the drill and the work hardening of the workpiece causes the tool failure.


Author(s):  
А.К. Martusevich ◽  
◽  
А.А. Yepishkina ◽  
L.R. Dilenyan ◽  
◽  
...  

Burn disease affects the functioning of almost all functional systems, having a negative effect on them due to the development of endotoxicosis and vascular disorders. At the same time, the greatest attention is paid to the shifts that form in the systemic hemodynamics, primarily in the coronary and pulmonary blood flow, which can cause the development and progression of life-threatening conditions. At the same time, the microcirculatory system is also undergoing changes, but these changes have been studied in much less detail. The aim of this research was to study the state of skin microcirculation in healthy and burned rats. The experiment was carried out on 20 adult male Wistar rats divided into two equal groups. The first group of animals (n=10) was a control group (intact), with its representatives there were not any manipulations, except for a single study of the state of microcirculation. Rats of the second (main) group (n=10) were simulated contact thermal burn using their own patented method. The assessment of microcirculation parameters in the main group of animals was carried out by laser Doppler flowmetry on the device "LAKK-M" on the 1st day (2-3 hours after the injury), on the third and tenth days after the burn period. It was found that thermal injury has a negative impact on the microcirculation system, which is seen in a decrease in the intensity of blood flow through small-diameter vessels. This is achieved by reflex vasospasm, reducing the release of nitrogen oxide by endothelial cells and activating precapillary sphincters, and simultaneously activating the shunting ways of cardiac shunt from the arterial directly to the venous channel, bypassing the capillaries. Thus, in the post-thermal period, a compensatory "robbing phenomenon" is realized in the border zone of the burn, which requires pathogenetic correction.


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