Purpose: In modern industry, titanium is recognised for its remarkable wear resistance and strength. However, its poor thermal conductivity poses a problem because it shortens the life cycle of cutting tools. Researchers have focused on enhancing the service life of cutting-edge tools, cutting production costs by using new coating materials, and identifying appropriate materials for these coatings. Design/methodology/approach: The experimental design involved tests with controlled cutting speeds of 150, 175, 200, and 225 m/min, feed rates of 0.2, 0.25, and 0.30 mm/rev, and cutting depths of 0.5, 1.0, and 1.2 mm. Titanium with a diameter of 25 mm and a length of 200 mm was prepared for the turning test over a machining distance of 20 mm. The chips obtained from the cutting test were observed and analysed using a scanning electron microscope to investigate the effect of the tool coating on the characteristics of the chip formation mechanism. Findings: The study revealed that inserts coated with AlCrSiTiN produced the characteristic of long twisted chips transitioning into continuous chips with shorter twisting distances than uncoated cermet inserts. The uncoated cermet inserts resulted in a greater twisting distance based on an examination of the chips with a scanning electron microscope, revealing more pronounced jaggedness in the fragments produced by the cermet turning inserts, which also possessed a larger average clearance than the inserts coated with AlCrSiTiN and TiAlSiN. Furthermore, the uncoated cermet inserts showed less wear at lower cutting speeds than the other types of inserts. Conversely, the TiAlSiN-coated inserts exhibited less wear at higher cutting speeds than the inserts of different materials. Research limitations/implications: The triangularly shaped inserts were cermet inserts coated with AlCrSiTiN or TiAlSiN via the PVD method and were used for dry turning. Practical implications: Wear of cutting-edge tools is a problem in turning of titanium. Therefore, it is crucial to identify methods to minimise wear and extend the service life considering the investment worthiness. Likewise, efforts are being made to develop new coatings tailored to the materials. Originality/value: The research could provide guidelines for reducing the wear generated in cutting tools and increasing the service life of cutting edges by adjusting the machining parameters.
Przedmiotem badań opisanych w niniejszej pracy jest proces zużywania elementów pary ciernej ze stykiem konforemnym zachodzący w obecności medium eksploatacyjnego z dodatkiem modyfikującym o zdefiniowanym składzie. Proces zużywania analizowano w aspekcie zmiany cech geometrycznych współpracujących elementów, a więc wielkości, najczęściej wykorzystywanych jako wskaźniki zużycia narzędzi skrawających
EN
The subject of the investigations described in this paper is the process of wear of friction pair elements with conformal contact occurring in the presence of operating medium with a modifying additive of defined composition. The wear process was analyzed in terms of changing geometric characteristic features of cooperating elements, i. e. size, most often used as indicators of wear of cutting tools.
Chain trench excavators are widely used in the world for trenching in agriculture, laying underground cables, digging trenches. In this study, the research object is a small chain-type trench excavator. The purpose of the study is to evaluate and select the parameters of the chain loader to the machine productivity and evaluate the results of the experimental machine theory calculation. Experimental measurement parameters include machine speed when working, chain speed, blade distance adjustment on the chain. Research method is to conduct experiments using Taguchi method to design experiments and Minitab software to analyze data. Experimental results and numerical analysis determined that the optimal set of parameters was the distance of 2 cutting edges on the chain, the active sprocket rotation speed for the highest productivity. Compared with the results from the theory using the design, the deviation of the optimal parameters is less than 5%. Experimental process design and parameter influence analysis by Taguchi method, ANOVA analysis have identified reasonable parameters, highest productivity target.
A general model is developed, and on its basis, there are special models formulated of the grinding process with crossed axes of the tool and workpiece with a profile in the form of a circle arc. A new method of control of the grinding process is proposed, which will provide processing by equidistant curves, and the amount of cutting of a circle equal to the allowance. This will increase the productivity and quality of grinding. The presented method of grinding implements the processing with the spatial contact line of the tool and workpiece. When the axes are crossed, the contact line is stretched, which leads to an increase of the contact area and, accordingly, to a decrease of the temperature in the processing area. This allows processing of workpieces with more productive cutting conditions.
5
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Scharakteryzowano cechy i zakres stosowalności procesów cięcia w odniesieniu do materiałów masywnych i porowatych. Przedstawiono główne aspekty oceny parametrów krawędzi ciętej tworzyw metalicznych i uwarunkowania prawne badania krawędzi ciętych. Przedstawiono opracowaną przez autorów metodykę badania struktury geometrycznej płaszczyzny cięcia kompozytowych pian aluminiowych po cięciu laserowym. Zaproponowano mikroskopię konfokalną jako metodę umożliwiającą badanie powierzchni o dużym udziale nieciągłości spowodowanych porowatością. Scharakteryzowano parametry jakości płaszczyzny cięcia oraz problemy metodyczne i techniczne wynikające z porowatej struktury pian metalicznych, a także obrazy 2D i 3D krawędzi piany aluminiowej po cięciu termicznym laserowym.
EN
The features and scope of the applicability of the cutting processes for massive and porous materials have been characterized. The paper presents the main aspects of the assessment of the cutting edge parameters of metallic materials and the legal conditions of the cutting edges inspection. The study methodology of the cutting plane geometric structure of aluminium composite foam after laser cutting, developed by the authors, has been discussed. Confocal microscopy has been proposed as a method for examining surfaces with a large share of discontinuity caused by porosity. The quality parameters of the cutting plane have been characterized, as well as methodological and technological problems arising from the porous structure of metallic foams and also 2D and 3D image of the aluminium foam edge after thermal laser cutting.
6
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
In modern multiuse cutting tools with exchange plate (e.g. with superfinishing edge or Wiper), the cutting edge is made without documenting the basis for optimizing its dimensions. The article presents a generalized edge wear model surrounded by a rounded tip. The proposed solution allows such a modification of edge corner – by determining the conditions of its work – to adapt the tool to stabilize the process of shaping the machined surface.
PL
W nowoczesnych, wielozadaniowych narzędziach skrawających z płytką wymienną (np. z powierzchnią dogładzającą lub wiper) krawędź skrawającą wykonuje się bez udokumentowania podstaw optymalizacji jej wymiarów. W artykule przedstawiono uogólniony model zużycia ostrza w otoczeniu zaokrąglonego wierzchołka. Zaproponowane rozwiązanie umożliwia taką modyfikację naroża ostrza – przez określenie warunków jego pracy – aby zaadaptować narzędzie do ustabilizowania procesu kształtowania obrabianej powierzchni.
It is important to shape the required properties of the surface layer in the technological process. This issue is an important problem due to the ability of the kinematic pair elements to the required reliable operation of machine parts. The latest generation devices work with increasing operational loads. This forces the search forever-newer construction materials or innovative manufacturing engineering technologies that would ensure high reliability and durability of machine components. For mechanical engineering, continue to be used on steel structures of machine parts. In the petrochemical and shipbuilding industry, stainless steels are very poplars. Those materials are used in the constructions of seawater and acid installations. Currently, a newer material with more favourable properties is two-phase stainless steel. This is the so-called duplex steel. It can be applied to pump shafts in acid or seawater solutions. Duplex cast steel is a difficult-to-cut material. It is important to determine the effect of cutting parameters on the surface quality of the shafts and wear of cutting edge. Traditional methods of finishing surface treatment of shafts are machining (turning, grinding, superfinishing). Considering the possibilities of equipping a marine power plant workshop, it would be best to use machining by turning. The paper specifies the relationship between the wear of the cutting edge and the geometrical structure of the machined surface as well as the type of tool material used and the shape of the cutting inserts.
The paper presents the results of studies on the influence of the addition of TaC–NbC on WC–5Co cemented carbides produced by pulse plasma sintering, and their effect on the hardness of cutting inserts and durability of cutting edges made from WC–5Co and WC–5Co–xTaC–NbC (x = 0.5, 2.5, 4.5) cemented carbides. The Vickers hardness was measured according to the PN–EN 23878:1996 standard and the durability was measured during machining using a conventional lathe where the shaft (counter-specimen) was made from 1.4541 stainless steel. The obtained results clearly show the positive effect of the addition of TaC–NbC on the hardness of cutting inserts and durability of cutting edges. The hardness increased by 5% for the WC–5Co–2.5TaC–NbC insert in comparison to pure the WC–5Co insert. The durability of the cutting edges also increased by 20% for the WC–5Co–2.5TaC–NbC insert.
PL
Węgliki spiekane są powszechnie stosowane do produkcji ostrzy skrawających oraz różnych elementów części maszyn. Jak wiadomo, podczas spiekania ziarna węglika wolframu (WC) ulegają rozrostowi, co jest zjawiskiem niepożądanym. W przypadku węglików spiekanych rozrost ziaren WC można skutecznie ograniczyć przez wprowadzenie do mikrostruktury m.in. węglika chromu (Cr3C2), węglika tantalu (TaC), węglika niobu (NbC), węglika wanadu (VC) czy węglika tytanu (TiC). Węgliki te pełnią funkcję inhibitorów wzrostu ziaren WC. Ponadto zastosowanie zaawansowanych metod metalurgii proszków, do których zalicza się metodę spiekania impulsowo- plazmowego (PPS), także przyczynia się do ograniczenia rozrostu ziaren m.in. ze względu na niższą temperaturę i krótszy czas spiekania. Metoda PPS należy do nowoczesnych metod spiekania wspomaganego polem elektrycznym (FAST). W ramach prezentowanej pracy dokonano analizy wpływu dodatku TaC–NbC w ilości 0,5; 2,5 i 4,5% mas., na twardość płytek oraz trwałość ostrzy skrawających z węglików spiekanych WC–5Co wytworzonych za pomocą metody PPS.
In the article the method of grinding with crossed axes of the tool and the workpiece got further developed. The work discloses a method of processing details having an external surface with a profile in the form of an arc of a circle of variable radius (for example, rolls of pipe rolling mills). The particular three-dimensional geometric models of the processing, shaping and profiling of abrasive wheels have been developed. A method for controlling the grinding process, which ensures the removal of allowances along equidistant curves has been offered. The developed method of grinding provides a constant depth of cutting according to the coordinate of profile processing. This is achieved at the expense of the synchronous inclination of the wheel and its insertion by the size of the allowance. The diameter of grinding wheel affects on the maximum angle of orientation of the wheel has been proven. It has been shown that increasing the diameter of the abrasive wheel has led to a slight decrease in value orientation angle.
In the paper results of research of the cutting forces in the milling process were presented. Relations between the number of edges, the length of the tool and the value of the cutting force components: F , F and F , were determined. Investigations were conducted for three xy z materials: Al alloy 3.1255, steel 1.0037 and cast iron 0.6025. One stated that both variables were affecting the value of the cutting forces, however observed changes are greater for the variable number of cutting edges.
PL
W artykule przedstawiono rezultaty badań sił skrawania w procesie frezowania. Określono relacje między liczbą ostrzy oraz długością narzędzia a wartością składowych sił skrawania: Fx, Fy i Fz. Badania przeprowadzono dla trzech materiałów: stopu Al 3.1255, stali 1.0037 i żeliwa 0.6025. Stwierdzono, że obydwie zmienne mają wpływ na wartość sił skrawania, przy czym zaobserwowane zmiany są większe dla zmiennej liczby ostrzy.
In the work the analysis of existent methods of determination of local and general forces of cutting at polishing of surfaces with a type as the arc of circumference is given. The dependence for determination of speed polishing and method for determination of thickness of the cut away layer on condition of equality of the tricked into and taken off volumes of material are offered. The method of determination of cutting forces, which takes into account cutting and deforming grain, is suggested. The method of determining the thickness of a cutting layer of one of the cutting edge, from the condition that the volume of material that is brought and is cut in each local point of contact spots has been proposed. The proposed method takes into account the compliance of the processing system and the discontinuity of the abrasive surface of the tool. By experimental way upper limits of thickness cutting layer when using different abrasive materials for a wide range of cutting speeds have been obtained.
12
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Scharakteryzowano cechy i zakres stosowalności procesów cięcia w odniesieniu do materiałów masywnych i porowatych. Przedstawiono główne aspekty oceny parametrów krawędzi ciętej tworzyw metalicznych i uwarunkowania prawne badania krawędzi ciętych. Przedstawiono opracowaną przez autorów metodykę badania struktury geometrycznej płaszczyzny cięcia kompozytowych pian aluminiowych po cięciu laserowym. Zaproponowano mikroskopię konfokalną jako metodę umożliwiającą badanie powierzchni o dużym udziale nieciągłości spowodowanych porowatością. Scharakteryzowano parametry jakości płaszczyzny cięcia oraz problemy metodyczne i techniczne wynikające z porowatej struktury pian metalicznych, a także obraz 2D i 3D krawędzi piany aluminiowej po cięciu termicznym laserowym.
EN
The features and scope of the applicability of the cutting processes for massive and porous materials have been characterized. The paper presents the main aspects of the assessment of the cutting edge parameters of metallic materials and the legal conditions of the cutting edges inspection. The study methodology of the cutting plane geometric structure of aluminium composite foam after laser cutting, developed by the authors, has been discussed. Confocal microscopy has been proposed as a method for examining surfaces with a large share of discontinuity caused by porosity. The quality parameters of the cutting plane have been characterized, as well as methodological and technological problems arising from the porous structure of metallic foams and also 2D and 3D image of the aluminium foam edge after thermal laser cutting.
13
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
W obróbce wysokowydajnej występują duże przekroje warstwy skrawanej oraz duże przekroje wiórów. Duże wymiary wiórów powodują utrudnioną ich ewakuację ze strefy skrawania. Przebadano wpływ zarysu krawędzi skrawającej freza na wielkość i kształt wiórów w procesie wysokowydajnego frezowania stopu aluminium.
EN
In the high-performance machining there are large sections of cutting layer and large sections of the chips. The large dimensions of the chips cause impeded their evacuation from the cutting zone. The influence of the cutting edge profile of the milling cutter on the size and shape of the chips in the high-performance cutting of aluminum alloy was determined.
14
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Zaprezentowano wybrane wyniki badań wpływu dodatków w postaci inhibitorów wzrostu typu TaC-NbC oraz Cr3C2 do nanowęglików spiekanych na trwałość ostrzy skrawających z nich wykonanych. Badania wykazały, że nanowęgliki spiekane z dodatkiem inhibitorów wzrostu charakteryzują się większą twardością oraz trwałością niż nanowęgliki spiekane bez tych dodatków.
EN
The article presents the selected results of influence of the TaC-NbC and Cr3C2growth inhibitors on durability of cutting edges made of nanocrystalline cemented carbides. Studies have shown that the nanocrystalline cemented carbides with growth inhibitors characterize greater hardness and durability than nanocrystalline cemented carbides without above additions.
15
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Przedstawiono wyniki badań obróbki zgrubnej frezami z ciągłym falistym profilem krawędzi skrawającej. W szczególności określono wpływ różnych falistych zarysów krawędzi skrawającej na przebieg siły skrawania i drgania przy frezowaniu stopu aluminium.
EN
The results of the research in rough machining using end mill cutter with wavy shape of the cutting edge were presented. In particular the influence of various wavy profiles of the cutting edge on cutting forces and vibrations during aluminum milling was determined.
This article is aimed to demonstrate the effect of cutting material and geometry of inserts chip breaker for dimensional accuracy in turning. The experiment is aimed on measuring compliance with dimensional accuracy in turning of samples from steel 11 523 at a constant feed rate and depth of cut, with varying spindle speeds. Machining was performed by using a different types of replaceable inserts. The measurement results will be evaluated in terms of the impact of differ-ent geometry characteristics and changing speeds spindle.
PL
Celem artykułu jest przedstawienie wpływu obrabianego materiału i geometrii noża na wymiarową dokładność procesu toczenia. Eksperyment jest zorientowany na pomiar zgodności próbek wykonanych ze stali 11 523 z zadaną dokładnością wykonania zawartą w dokumentacji technicznej, ze stałym posuwem oraz głębokością toczenia oraz zmienną prędkością obrotową. Obróbka została wykonana z użyciem różnego rodzaju narzędzi. Wyniki pomiarów oceniono z perspektywy wpływu charakterystyk geometrycznych oraz zmian prędkości obrotowej.
17
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Purpose: The cutting tools of high speed steel or cemented carbide need to be regenerated in many cases. This involves stripping the remnants of the initial coatings. The effects of chemical removal of the PVD TiN, TiAlN, TiN/(TiAlSi)N/TiN and TiZrN/10x(TiN/ZrN)/TiN coatings on some elements of geometry of cutting edges and the adhesion of subsequent coatings deposited on the cutting inserts are considered. Design/methodology/approach: Scanning electron microscopy is used to examine the structures after the various stages of inserts regeneration: with the initial coating, after it is chemically stripped and subsequently deposited. Geometry of cutting edges, i.e. roughness, edge roundness radius and 2D and 3D geometric structure of rake and flank faces, as well as the adhesion of subsequent coatings deposited on the inserts in the regeneration process are determined. Findings: The chemical coating stripping process did not cause unfavourable changes in the roughness parameter Ra of the rake and flank faces of cutting inserts, or in the roughness of their cutting edges. Subsequent coatings deposited on the decoated inserts had a marginally lower adhesion, but in the case of TiN coated cemented carbide, the latter coating had better adhesion than the original. Surface analyses showed that the PVD coating stripping methods were effective for TiN and TiAlN coated high speed steel HS6-5-2 inserts, as well as for TiN coated and commercially TiN/(TiAlSi)N/TiN coated cemented carbide inserts. Research limitations/implications: The paper is concerned with geometry of cutting edge and adhesive properties of subsequent coatings. To verify fully the effectiveness of the methods described further research on different coating removal from tools made of various tool materials should be carried out. Practical implications: The methods and chemicals used for removal of the initial PVD TiN, TiAlN and TiN/(TiAlSiN)/TiN coatings from high speed steel and cemented carbide inserts proved effective and may be used in the regeneration process of cutting tools. Originality/value: The effects of chemical removal of mono and multilayer PVD coatings from cemented carbide and high speed steel inserts on the regenerated cutting edges quality have been determined.
Sialon jest ceramicznym materiałem narzędziowym coraz częściej stosowanym na ostrza skrawające ze względu na to, że łączy w sobie zalety ceramiki tlenkowej (ceramika biała i czarna) oraz ceramik beztlenkowych, zawierających Si3N4. Te korzystne właściwości ostrzy skrawających z sialonu sprawiają, że jest efektywnie stosowany do wysokowydajnej obróbki głównie materiałów trudno skrawalnych. W artykule przedstawiono w formie syntetycznej złożony proces wytwarzania ostrzy skrawających z tego perspektywicznego materiału narzędziowego oraz przedstawiono wyniki badań własnych dotyczących struktury i analizy widmowej β’-SiAlON.
EN
SiAlON is the tool ceramics more and more often applied on the cutting edges because of specific properties. SiAlON is a material which join of both advantages of oxides (white and black ceramics) and oxides-free ceramics contained the Si3N4. These advantages of cutting edges made of the SiAlON cause that this material is effectively applied to high-duty machining especially to hard machining materials. In the paper the complex manufacturing process of cutting edges and results of own researches concerned structure and spectroscopic analysis of the β’-SiAlON is presented in synthetic form.
19
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW