scholarly journals Study of the processing of small diagnostic creations on a fluid sourcing by spiral survivals

Author(s):  
Roman Karpyk ◽  
◽  
Nazar Kostiuk ◽  

The article considers the features of the drilling process where there is a change in temperature, hole diameter, and displacement relative to the axis and the impact on the tool, when machining holes with high-speed steel drills there is wear of the transverse edge which is completely rounded to create a conical surface. There is a decrease in the negative value of the front corners on the transverse edge of the decrease in axial force, which led to a decrease in the intensity of wear of the transverse edge. In order of increasing axial force, respectively, and the intensity of wear of the transverse edge, were sharpened and recommended sharpening methods that provide high performance of the drill, the greatest stability, increased drilling accuracy, as well as the lowest cutting force. The analysis of influence of technological methods and ways and equipment on accuracy and quality of deep openings of small diameter is carried out. The effects of the method of lubricating coolant supply on the tool stability and processing productivity are investigated. The analysis of processing on the metal-cutting equipment with constructive development of the device is executed. Also, the stress-strain state of the drilling process by the finite element method with the analysis of external influences on the twist drill is carried out. The results of the research substantiate and recommend technological methods that reduce the deformation of the tool and, as a consequence, increase the quality and accuracy of the dimensions of deep holes of small diameter.

2006 ◽  
Vol 113 ◽  
pp. 559-564 ◽  
Author(s):  
Alexander S. Chaus ◽  
J. Chovanec ◽  
M. Legerská

As-cast high-speed steels heat-treated have completely much lower impact toughness than that of the steels of a similar chemical composition but undergone hot working – rolling or forging. That is attributed to the influence of eutectic carbides, which especially being coarse, provide easily brittle intergrain fracture sites under low stress intensity factor levels. This is especially real for cast cutting tools. In order to exhibit good all-round performance the impact toughness enhancement of as-cast high-speed steels is obligatorily needed. In this connection it is expedient to turn from high-speed steels of conventional ledeburitic origin to high-speed steels of hypereutectoid and ferritic-carbidic ones with considerably lower carbide heterogeneity resulting in enhanced impact toughness. In the present work special features of the structure, phase composition and properties of such high-speed steels designed for cast tool are studied. In order to substitute tungsten by chromium in as-cast high-speed steel a special alloying system has also been developed.


2014 ◽  
Vol 788 ◽  
pp. 329-333
Author(s):  
Rui Zhou ◽  
Xiao Gang Diao ◽  
Jun Chen ◽  
Xiao Nan Du ◽  
Guo Ding Yuan ◽  
...  

Effects of sintering temperatures on the microstructure and mechanical performance of SPS M3:2 high speed steel prepared by spark plasma sintering was studied. High speed steel sintering curve of continuous heating from ambient temperature to 1200°C was estimated to analyze the sintering processes and sintering temperature range. The sintering temperature within this range was divided into groups to investigate hardness, relative density and microstructure of M3:2 high-speed steel. Strip and quadrate carbides were observed inside the equiaxed grains. SPS sintering temperature at 900°C can lead to nearly full densification with grain size smaller than 20μm. The hardness and bending strength are higher than that of the conventionally powder metallurgy fabricated ones sintered at 1270°C. However, fracture toughness of the high speed steel is lower than that of the conventional powder metallurgy steels. This can be attributed to the shape and distribution of M6C carbides which reduce the impact toughness of high speed steels.


2020 ◽  
Vol 308 ◽  
pp. 110-118
Author(s):  
Mirosław Bonek ◽  
Eva Tillová

The article presents the results of research on the impact of laser surface treatment on selected steel properties. The laser treatment consisted of remelting and alloying high speed steel using hard ceramic phase powders. A high-power diode laser was used in the experiment to examine the effect of parameters such as beam power and powder type on the structure and properties of the surface layer. A structural mechanism was observed consisting in obtaining, after laser processing, a super fine crystalline structure and a dendritic structure at the remelting zone. Structural changes have been found to be associated with improved properties such as hardness, microhardness and wear resistance. Steel treated with conventional heat treatment was used as a comparative material.


Author(s):  
Manudul Pahansen de Alwis ◽  
Karl Garme

The stochastic environmental conditions together with craft design and operational characteristics make it difficult to predict the vibration environments aboard high-performance marine craft, particularly the risk of impact acceleration events and the shock component of the exposure often being associated with structural failure and human injuries. The different timescales and the magnitudes involved complicate the real-time analysis of vibration and shock conditions aboard these craft. The article introduces a new measure, severity index, indicating the risk of severe impact acceleration, and proposes a method for real-time feedback on the severity of impact exposure together with accumulated vibration exposure. The method analyzes the immediate 60 s of vibration exposure history and computes the severity of impact exposure as for the present state based on severity index. The severity index probes the characteristic of the present acceleration stochastic process, that is, the risk of an upcoming heavy impact, and serves as an alert to the crew. The accumulated vibration exposure, important for mapping and logging the crew exposure, is determined by the ISO 2631:1997 vibration dose value. The severity due to the impact and accumulated vibration exposure is communicated to the crew every second as a color-coded indicator: green, yellow and red, representing low, medium and high, based on defined impact and dose limits. The severity index and feedback method are developed and validated by a data set of 27 three-hour simulations of a planning craft in irregular waves and verified for its feasibility in real-world applications by full-scale acceleration data recorded aboard high-speed planing craft in operation.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Jie Hong ◽  
Tianrang Li ◽  
Zhichao Liang ◽  
Dayi Zhang ◽  
Yanhong Ma

Aeroengines pursue high performance, and compressing blade-casing clearance has become one of the main ways to improve turbomachinery efficiency. Rub-impact faults occur frequently with clearance decreasing. A high-speed rotor-support-casing test rig was set up, and the mechanism tests of light and heavy rub-impact were carried out. A finite element model of the test rig was established, and the calculation results were in good agreement with the experimental results under both kinds of rub-impact conditions. Based on the actual blade-casing structure model, the effects of the major physical parameters including imbalance and material characteristics were investigated. During the rub-impact, the highest stress occurs at the blade tip first and then it is transmitted to the blade root. Deformation on the impact blade tip generates easily with decreased yield strength, and stress concentration at the blade tip occurs obviously with weaker stiffness. The agreement of the computation results with the experimental data indicates the method could be used to estimate rub-impact characteristics and is effective in design and analyses process.


2016 ◽  
Vol 112 ◽  
pp. 469-478 ◽  
Author(s):  
Zhang Qiankun ◽  
Jiang Yao ◽  
Shen Weijun ◽  
Zhang Huibin ◽  
He Yuehui ◽  
...  

2006 ◽  
Vol 315-316 ◽  
pp. 51-55
Author(s):  
R.D. Han ◽  
B.L. Yin

As high-speed steel tap is incapable of small-hole tapping (M3) in hardened steel, vibration tapping is introduced in this paper to solve this problem. Theoretic analysis with fracture mechanics indicates that the impact effect of the tap on the workpiece results in extended micro cracks and a much lower tapping torque. And the torsional rigidity of the tap is enforced in vibration tapping as proved by dynamic analysis. The experimental results show that with well chosen amplitudes, tapping torque decreases as vibration frequency increases and increases with the increase of net cutting time ratio, with the latter being the more significant influencing factor. In vibration tapping of hardened steel, 24 threads can be machined with a single tap. Vibration tapping is then proved to be a practical solution to the problem of small-hole tapping in hardened steel.


2021 ◽  
Author(s):  
Majid Tolouei-Rad ◽  
Muhammad Aamir

Drilling is a vital machining process for many industries. Automotive and aerospace industries are among those industries which produce millions of holes where productivity, quality, and precision of drilled holes plays a vital role in their success. Therefore, a proper selection of machine tools and equipment, cutting tools and parameters is detrimental in achieving the required dimensional accuracy and surface roughness. This subsequently helps industries achieving success and improving the service life of their products. This chapter provides an introduction to the drilling process in manufacturing industries which helps improve the quality and productivity of drilling operations on metallic materials. It explains the advantages of using multi-spindle heads to improve the productivity and quality of drilled holes. An analysis of the holes produced by a multi-spindle head on aluminum alloys Al2024, Al6061, and Al5083 is presented in comparison to traditional single shot drilling. Also the effects of using uncoated carbide and high speed steel tools for producing high-quality holes in the formation of built-up edges and burrs are investigated and discussed.


2019 ◽  
Vol 2019 (12) ◽  
pp. 33-41
Author(s):  
Bori Mokrickiy ◽  
Dmitriy Savin ◽  
Yana Konyuhova ◽  
Anna Morozova

The purpose of the work – development of recommendations on correct choice support of hard-alloy plate quality according to the conditions specified of plates operation. In the work there is formed a new approach to the analysis of hard-alloy plates of a metal-cutting tool which develops an approach existing in the RSSs and conditions a necessity to develop a metrological support of plate quality for the conditions of specified working conditions. The approach is based on the simultaneous account of some plate parameters by means of the introduction of conditional quality grades. The investigation results: - the impact of the value spread of mass and dimensions of plates upon plate quality is defined, - the criteria of their division into grades depending on a spread value are defined. Conclusions: the results of plate classification according to the parameters: “plate weight”, “plate length”, Plate width” and “plate thickness differ considerably; plate weight effects most the output parameters of part work-piece machining process, plate thickness impact is the smallest; home plate quality is not so acceptable for the billet high-performance machining of precision parts; the adaptation of acting RSSs to plates taking into account the requirements for modern NC machines; under current conditions a technologist of an engineering enterprise-consumer of plates is unable to order meaningfully their essential number because of the domination of low-quality plates.


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