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1

Formowanie wtryskowe proszku

Matula Grzegorz

LAB Laboratoria, Aparatura, Badania

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2020

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R. 25, nr 2

33--37

2

Porous material produced by ceramic injection molding

Matula G., Krzysteczko J.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 71, nr 1

14--21

EN

Purpose: The aim of this research is presented the process of alumina injection molding with a multicomponent binder system based on polymer (polypropylene – PP/polyethylene- HDPE), paraffin wax (PW) and stearic acid (SA). Debinding and sintering process was also studied. Design/methodology/approach: The volume fractions of powder in the feedstocks were 50%vol and the volume of polypropylene and polyethylene were changed from 0-22%vol. The concentrations of SA were kept at 6%vol. The feedstock was heated to melt the binder and injected into a mold. Debinding process was carried out after injection step. The organic part was removed through combination of solvent and thermal debinding. Samples were sintered at 1200-1600°C in one cycle with debinding process. Findings: Thermogravimetric analysis (TGA) was performed to determine decomposition temperatures of polypropylene, polyethylene, paraffin wax and stearic acid. Morphology of alumina powder by scanning electron microscopy (SEM) was disclosed. The microstructure and properties was tested to see how the selected sintering parameter ,as a temperature, affects the structure. Originality/value: The paper presents ceramic injection molding process of alumina parts and sintering to produce porous material which is possible to use as a preform for infiltration by aluminium alloys.

3

Ceramic injection moulding process of alumina

Matula G., Krzysteczko J., Lipowska B.

Journal of Achievements in Materials and Manufacturing Engineering

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2014

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Vol. 67, nr 1

32--38

EN

Purpose: The aim of this research is presented ceramic injection moulding process of alumina parts. Firstly alumina parts was performed by using binder system. The binder consisted of a mixture of a polypropylene (PP), paraffin wax (PW) and stearic acid (SA). Design/methodology/approach: The volume fractions of powder in the feedstocks were changed from 40-50%vol and the volume of polypropylene were changed from 20-34%vol The concentrations of SA were kept at 6%vol. Secondly the feedstock was heated to melt the binder and injected into a mould. Thirdly the polymeric and wax binder was debinding by using solvent and thermal debinding. The thermal cycle was performed based on the results of the thermogravimetric analysis. Previously samples were sintered in one cycle with debinding of the binder during 23 h at 1400°C using heating rates of 0.5°C/min. Findings: Thermogravimetric analysis (TGA) was performed to determine decomposition temperatures of polypropylene, paraffin and stearic acid. Morphology of alumina powder by scanning electron microscopy (SEM) was disclosed. Originality/value: The paper presents ceramic injection moulding process of alumina parts for selected samples.

4

Application of powder injection moulding for manufacturing of tool composite materials

Matula G., Jędrzejewska-Anioł A., Niespodziański J.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 59, nr 2

80--85

EN

Purpose: The goal of this work is development of the tool composites on the basis of T15 HSS contained 10% of carbides. This tool material were manufactured by Powder Injection Moulding method and sintered. Design/methodology/approach: Torque-load test, rheological tests, thermal debinding, sintering, hardness test and microstructure examinations. Findings: Examination of the effect of the binder type and portion on structure and properties of the experimental tool materials revealed that using the stearic acid for covering the carbides surface reduces viscosity, thus improving technological properties of the feedstock. Employment of polypropylene instead of the high density polyethylene reduces viscosity and torque-load of the investigated feedstocks. Therefore, there is a possibility to increase the portion of the metallic and ceramic powder. Practical implications: Stearic acid significantly reduces the viscosity of tested polymer-powder mixtures, so its use is justified. The share of the binder in materials, injection molded or extruded should be minimal and allows only the formation of the slurry. Too high proportion of binder creates difficulties during the degradation and causes greater shrinkage and possibility of a distortion during sintering. Employment of polyethylene instead of the high density polypropylene reduces viscosity and torque-load of the investigated feedstocks. Therefore, there is a possibility to increase the portion of the metallic or ceramic powder. This results in a lower deformation probability and in a lower sinter shrinkage. Originality/value: In the paper the using extruding of the polymer-powder mix gives the possibility to fabricate cermets which, with their structure and mechanical properties, fill the gap in tool materials between the high-speed steels and cemented carbides.

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Carbide alloyed composite manufactured with the PIM method

Matula G.

Archives of Materials Science and Engineering

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2010

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Vol. 43, nr 2

117-124

EN

Purpose: Development of a new generation tool materials on the basis of M2 high speed-steel reinforced with the carbides. Application of powder injection moulding as a manufacturing method gives the possibility to produce these materials in a mass scale with relative low cost of production. Design/methodology/approach: Powder Injection Moulding, solvent debinding, sintering, thermogravimetric analysis, microstructure examination, porosity examination, Findings: To manufacture the proposed new tool materials was used powder injection moulding processes. It was found out based on the investigations carried out that the powder injection moulding method is suitable for fabrication of M2 high speed-steel reinforced with the carbides. The main advantage of the presented experimental tool materials is the wide sintering window being only about 5°C oftentimes in case of the high-speed steels; whereas, it is about 40°C for the investigated material. Practical implications: Application of powder metallurgy and especially powder injection moulding to manufacturing of high speed-steel reinforced with the carbides gives the possibility to obtain tool materials with the relative high ductility characteristic of steel and high hardness and wear resistance typical for cemented carbides. Originality/value: The powder injection moulding gives the possibility to fabricate carbide alloyed composite which, with their structure and mechanical properties, fill the gap in tool materials between the high-speed steels and cemented carbides.

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Struktura i własności spiekanej stali szybkotnącej HS6-5-2 formowanej wtryskowo

Dobrzański L. A., Matula G.

Hutnik, Wiadomości Hutnicze

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2005

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Vol. 72, nr 3

187--194

PL

Na podstawie porównania struktury i własności stali szybkotnących HS6-5-2 wytwarzanych metodą formowania wtryskowego proszku, formowania niskociśnieniowego, prasowania i spiekania oraz stali komercyjnych wytwarzanych metodą ASEA-STORA stwierdzono, że w strukturze wszystkich badanych stali szybkotnących w stanie spiekanym występują drobne węgliki równomiernie rozmieszczone w osnowie stali. Zastosowanie atmosfery zawierającej azot podczas spiekania, powoduje formowanie się drobnych, sferycznych węglikoazotków typu MX, trwałych w wysokiej temperaturze spiekania i austenityzowania. Wspólną zaletą stali formowanych wtryskowo oraz niskociśnieniowo jest szerszy zakres temperatury spiekania w stosunku do stali wytwarzanych przez tradycyjne prasowanie i spiekanie, dla których wynosi zaledwie 5 °C. Stale formowane niskociśnieniowo charakteryzują się najniższą temperaturą spiekania oraz najwyższą gęstością, wynikającą z wysokiego stężenia węgla pochodzącego z procesu degradacji lepiszcza. Dodatkowo wyższe stężenie węgla powoduje zwiększenie udziału austenitu szczątkowego i niższą twardość po hartowaniu i odpuszczaniu. Stal formowana wtryskowo w stanie obrobionym cieplnie osiąga twardość porównywalną do twardości stali komercyjnej typu ASP 23, wskazując na zasadność stosowania metody formowania wtryskowego proszku do wytwarzania stali szybkotnących. Formowanie wtryskowe proszku umożliwia wytwarzanie narzędzi na gotowo, tj. z pominięciem obróbki plastycznej i ubytkowej, koniecznej w przypadku stali typu ASP 23. Ponadto czas procesu degradacji i spiekania stali formowanych wtryskowo jest o ok. 10h krótszy niż stali formowanych niskociśnieniowo, co jest spowodowane zastosowaniem lepiszcza dwuskładnikowego.

EN

On the basis of comparison of structure and properties of high-speed steels HS6-5-2 manufactured by Powder Injection Moulding, Pressureless Forming, compacted and sintered andproduced by comercial ASEA-STORA method it has been shown that the structure of all examined high-speed steels in sintered state are small and spherical carbides uniformly distributed inferrite matrix. The use ofatmosphere with nitride during sintering process cause formation of the small and spherical carbonitrides MX type stable in high temperaturę of sintering and austenitizing in steel matrix. The common feature of steel formed by Powder Injection Moulding and Pressureless Forming is broaden range of sintering temperaturę in relation to steels produced by conventional compacting and sintering which equals only 5°C. Steels formed by Pressureless Forming are characterized by the lowest sintering temperature and the highest density resulting from high carbon content coming from thermal debinding process of a binder. Moreover, higher carbon concentration causes increase of the retained austenite portion and lower hardness after quenching and tempering. The steel formed by Powder Injection Moulding and heat treated obtain comparable hardness to hardness of commercial ASP 23 steel showing the reason of high speed steel manufacturing by Powder Injection Moulding. The Powder Injection Moulding makespossible production of final shape tools without plastic working and machining which is necessary in case of ASP 23 type steel. Moreover time of thermal debinding and sintering process of steels formed by Powder Injection Moulding is about 10 h shorter than steels formed by Pressureless Forming because two-component binder application.