BazTech - Yadda

1

Effect of Cutting-Edge Geometry on the Machinability of 316L Austenitic Steel

Grabowski Marcin, Małek Marcin, Teimouri Reza, Skoczypiec Sebastian

Advances in Science and Technology. Research Journal

|

2024

|

Vol. 18, no 1

110--117

EN

The paper focuses on the problem of selecting the correct tool geometry in high-speed milling of 316L stainless steel. Carbide milling cutters with two configurations of helix angle (40/42 degrees for tool#1 and 35/38 degrees for tool#2) with different cutting edge radiuses rn (i.e. 4 µm, 6 µm, 8 µm, 10 µm and 12 µm) were prepared and their impact on cutting force and roughness were analyzed. The obtained results revealed that the small changes in cutting edge radius rn have a significant effect on both cutting forces and surface roughness. In this context, irrespective to the type of the tool, increasing the cutting edge radius results in further cutting force. However, increasing the cutting edge radius shows different behavior on roughness while using different tool helix angles. For the tool#1, it was found that the surface roughness increases by increasing the cutting edge radius from 6 μm to 12 μm; while in the samples machined by tool #2, increase in cutting edge radius results in reduction of roughness. It was also found that irrespective to the values of cutting edge radius, the cutting force while using tool #1 is slightly less than the tool#2. In addition, the induced milling surface roughness of the samples machined by tool#2 is significantly less than the tool#1 where the mean value of Ra was reduced from 2.55 µm to 0.35 µm

2

Technological Possibilities of the Carbide Tools Application for Precision Machining of WCLV Hardened Steel

Grabowski Marcin, Gawlik Józef, Krajewska-Śpiewak Joanna, Skoczypiec Sebastian, Tyczyński Piotr

Advances in Science and Technology. Research Journal

|

2022

|

Vol. 16, no 1

141--148

EN

Precision milling of free (curved) surfaces with the use of monolithic milling cutters is used in the production of hardened steel elements such as dies, molds, or press tools. Precision milling processes are carried out with the following milling parameters: axial cutting depth ap <0.3 mm, cutting width ae <0.5 mm and the required machining accuracy below 40 µm. The quality of the obtained surfaces in injection molds is directly transferred to the quality of the molded part. One of the key criteria for the manufactured elements is the surface quality which is mainly assessed by the roughness parameters. Due to the use of carbide tools high reliability and quality of machining is obtained which allows to eliminate the grinding process. In precision milling processes, due to the very small radius of the cutting edge and the cross-sections of the cutting layers, the conditions that must be met for the decohesion process to occur are fundamentally diff erent from macro-scale. The minimum value range of ap and ae parameters was determined in a carried-out experiment, which allows for stable and repeatable machining. The tests were carried out with double-edge shank cutters with a diameter of 6 mm on a workpiece made out of WCVL hardened steel 45–47 HRC. Recommended machining conditions have been defi ned to ensure the required technological quality of the surface layer. The research was fi nanced under the research project POIR.01.01.01-000890/17 co-fi nanced by the European Union from the European Regional Development Fund.

3

Konečno-èlementnaâ modelʹ èlektronno-lučevoj pajki tverdosplavnyh režuŝih èlementov k opravke

Goranskij G.G., Pobol A.I

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

|

2020

|

Z. 26 (176)

44-55

RU

Sozdany obobŝennye konečno-èlementnye (KÈ) modeli èlektronno-lučevoj obrabotki (ÈLO) poverhnostej dlâ materialov s suŝestvenno otličaûŝimisâ teplofizičeskimi svojstvami, pozvolâûŝie proizvoditʹ rasčet i optimizaciû režimov processa. Dlâ izdelij raznoj geometrii, učityvaâ termodinamiku processa i temperaturnye zavisimosti svojstv materialov, upravlââ geometriej èlektronnogo pučka i ciklogrammoj processa, optimizirovany diapazony ènergeti českih parametrov ÈLO. KÈ modelirovanie nagreva poverhnosti pri ÈLO provedeno dlâ detali ploskoj formy stacionarnym istočnikom so skaniruûŝej razvertkoj, a takže pri vozdejstvii v režime linejnogo peremeŝeniâ luča bez skaniruûŝej razvertki. Dlâ optimizacii èlektronno-lučevogo oplavleniâ pri pajke predložena termodinamičeskaâ KÈ modelʹ, učityvaûŝaâ geometričeskie osobennosti rezcovyh vstavok i teplofizičeskie svojstva sostavlâûŝih ih materialov. Pokazano, čto učet temperaturnoj zavisimosti teplofizičeskih svojstv materialov pozvolâet realizovyvatʹ shemy ÈLO s menʹšej prodolžitelʹnostʹû vozdejstviâ pučka bolʹšej moŝnosti.

EN

Generalized finite-element models for the electron-beam treatment of the surface of materials with significantly different thermophysical properties have been created, allowing the calculation and optimization of process conditions. For products of different geometries, taking into account the thermodynamics of the process and the temperature dependences of the properties of materials, controlling the electron beam geometry and the process cycloramas, the ranges of energy parameters of electron beam processing have been optimized. Finite-element modeling of surface heating during electron-beam processing was carried out for a flatshaped part by a stationary source with scanning, as well as when exposed to linear beam movement without scanning. To optimize electron beam reflow during soldering, a thermodynamic finite-element model is proposed that takes into account the geometric features of the cutter inserts and the thermophysical properties of their constituent materials. It is shown that taking into account the temperature dependence of the thermophysical properties of the materials makes it possible to realize electron beam processing schemes with a shorter duration of exposure to a beam of greater power.

4

Zaokrąglanie krawędzi skrawających ostrzy z węglików spiekanych

Cichosz P., Kuzinovski M., Tomov M., Urych A.

Mechanik

|

2018

|

R. 91, nr 7

458--462

PL

Przedstawiono genezę zaokrąglania krawędzi ostrzy skrawających wykonanych z węglików spiekanych. Zaprezentowano różne obrabiarki i ścierniwa służące do wygładzania krawędzi skrawających. Porównano metody pomiaru promienia zaokrąglenia krawędzi. Zwrócono uwagę na możliwości zwiększenia trwałości narzędzi dzięki zastosowaniu nowych technologii wykańczania powierzchni roboczych narzędzi.

EN

The paper describes the origins of edge rounding of machine-cutting blades made of sintered carbides. Various processing machines and abrasive materials used to smoothen the cutting edges are presented. Various methods of measurement of the edge radius are compared. Stressed are the possibilities of improvement of tool durability through the use of new finishing process technologies for tool working surfaces.

5

Ultra-precision machining of stainless steel using coated carbide tool

Liew W.

Archives of Materials Science and Engineering

|

2008

|

Vol. 31, nr 2

117-120

EN

Purpose: This paper discusses the experimental work carried out to investigate the performance of coated carbide ool in ultra-precision machining of stainless steel and evaluates whether this tool can be used to fabricate a cavity with high form accuracy and surface finish on a stainless steel mould insert. Design/methodology/approach: The results obtained in the turning process and the machining of cavity on a mould insert under various conditions and parameters are examined. Findings: The experimental results obtained in the turning tests gave an important insight of the appropriate parameters and the condition to be used in the machining of cavity on a mould insert. The cavity machined on the stainless steel mould insert with the coated carbide tool in the presence of natural oil has superior form accuracy and surface finish. Research limitations/implications: Further research is needed to investigate the performance of the coated carbide tools in machining profiles of other shape and diameter. Practical implications: Profile with a superior form accuracy and surface finish can be machined on a stainless steel mould insert using a coated carbide tool instead of using a PCBN tool, a much more expensive tool. Originality/value: The paper presents original information on the ultra-precision machining of tool steels at low speeds. The paper is of interest to manufacturing engineers.