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EN
The goal of this study is to develop a method of manufacturing porous ceramic skeletons used as semi-finished products for reinforcement of composite materials or as filters. For manufacturing skeletons, only waste materials from coal combustion (fly ashes and bottom slags) as well as rubber granules from used tires and car parts were used. These granules were a pore-forming agent that underwent thermal degradation during sintering process. The influence of sintering temperature, portion, and type of rubber granules on the porosity of developed ceramic skeletons was determined. The study of structure of base materials and the developed ceramic skeletons in a scanning electron microscope as well as their X-ray phase analysis were made. Results will allow to predict phases that can be formed on the metal-reinforcement interface during pressure infiltration.
EN
Purpose: The goal of the paper is to develop technologies for manufacturing composite materials with casting aluminum alloy matrix reinforced by silicon AN AC-AlSi12 and to investigate the effect of the amount of the pore forming agent in the form of graphite MG 192 on the structure and properties of porous ceramic skeleton infiltrated with liquid aluminum alloy. Design/methodology/approach: The composite was manufactured by the use of porous material pressure infiltration method. Hardness test was carried out with Rockwell method in A scale. The wear resistance was measured by the use of TSM Instruments Tribometer. The tribomiter allows to realize dry friction wear mechanism conditions. Additionally the examinations on stereomicroscope of wear tracks were made. Findings: Composite materials reinforced by porous skeleton manufactured on the base Al2O3 particles show superior in mechanical properties and wear resistance than the aluminum alloy EN AC-AlSi12 constituting the matrix. The developed composite materials also have better wear resistance compared to the matrix. Practical implications: Tested composite materials can be applied in many industry branches, among others, in the automotive, aerospace industry and in manufacturing of professional sports equipment. Originality/value:The investigation results shows that the worked out technology of composite materials manufacturing can find the practical application in the production of near net shape and locally reinforced elements.
EN
Purpose: The purpose of this paper is to present the research results of modern metal matrix composite materials. The matrix material was EN AC - AlSi12 alloy while the reinforcement ceramic performs. In order to investigate the influence of reinforcing phase’s shape on tribological properties the comparison was made between the composite material based on preforms obtained by Al2O3 Alcoa CL 2500 powder sintered with addition of pore forming agent in form of carbon fibres Sigrafil C 10 M250 UNS from Carbon Group company and composite materials based on much more expensive commercial fibrous preforms. Design/methodology/approach: The composite was produced by the use of porous material pressure infiltration method. Obtained composite materials were examined with light and scanning electron microscopy. Hardness test was carried out with Rockwell method in A scale. Additionally, the wear resistance was measured by the use of device designed in the Institute of Engineering Materials and Biomaterials. The device realize dry friction wear mechanism of reciprocating movement conditions. Findings: The obtained results show the possibility of manufacturing the new composite materials by the method of porous sintered framework pressure infiltration based on the ceramic particles, with desired microstructure and properties, being a cheaper alternative for materials with base of ceramic fibers. Practical implications: Tested composite materials can be apply among the others in automotive and aircraft industries. Originality/value: Worked out technology of composite materials manufacturing can be used in the production of near net shape and locally reinforced elements.
4
Content available remote Structure and properties of ceramic preforms based on Al2O3 particles
EN
Purpose: The main goal of this project is to elaborate and optimize the method of manufacturing the porous, ceramic preforms based on Al2O3 particles used as the reinforcement in order to produce modern metal matrix composites by pressure infiltration method with liquid metal alloys. Design/methodology/approach: Ceramic preforms were manufactured by the sintering method of Al2O3 powder with addition of pore forming agent. The preform material consists of powder Alcoa Al2O3 CL 2500, however, as the forming factor of the structure of canals and pores inside the ceramic, agglomerated framework the carbon fibres Sigrafil C10 M250 UNS were used. The addition of carbon fibres was 30, 40 and 50% of weight. The TGA analysis of carbon fibres has been made. The investigations of the structure of powder Al2O3 Alcoa CL 2500, the used carbon fibres and the obtained ceramic preforms on the scanning electron microscope (SEM) have been made. The measurement of permeability of the obtained materials on the specially designed station has also been made. Findings: The obtained preforms are characterized by volumetric participation of ceramic phase of 15-31%, what is the result of differential addition of the pores forming agent, and the high permeability indicates on “the open porosity”. Research limitations/implications: The basic limit of the mentioned method is the possibility of obtaining preforms of porosity less than 85%, where in case of using the ceramic fibres the pores can be more than 90% of material volumetric. Practical implications: The manufactured ceramic preforms are widely used as the reinforcement to produce the composite materials by the infiltration method. That method allows manufacturing the metal elements locally reinforced and the near-net shape composite products. Originality/value: The received results show the possibility of obtaining the new preforms being the cheaper alternative for semi-finished products based on the ceramic fibres and the use of carbon fibres as the pores forming agent indicate that it is the high-quality process.
5
Content available remote Aluminium matrix composites fabricated by infiltration method
EN
Purpose: The aim of this work is to examine the structure and properties of metal matrix composites obtained by infiltration method of porous ceramic preforms by liquid aluminium alloy. Design/methodology/approach: Ceramic preforms were manufactured by the sintering method of ceramic powder. The preform material consists of powder Condea Al2O3 CL 2500, however, as the pore forming the carbon fibers Sigrafil C10 M250 UNS were used. Then ceramic preforms were infiltrated with liquid eutectic EN AC - AlSi12 aluminum alloy. Stereological and structure investigations of obtained composite materials were made on light microscope. The mechanical properties of obtained composite material were investigated in tensile strength test and hardness test. Findings: It was proved that developed technology of manufacturing of composite materials based on the porous ceramic Al2O3 preforms infiltrated by liquid aluminium alloy ensures expected structure and strength Hardness increased about twice compared to the matrix and this process can be used in practice. Practical implications: The presented metal matrix composites fabrication technology allows to obtain locally reinforced elements and near net shape products. Originality/value: Results show the possibility of obtaining the new aluminium matrix composite materials being the cheaper alternative for other materials based on the ceramic fibers.
6
Content available remote Composite materials based on porous ceramic preform infiltrated by aluminium alloy
EN
Purpose: The goal of this project is the optimization of manufacturing technology of the ceramic preforms based on Al2O3 powder manufactured by the pressure infiltration method with liquid metal alloy. Design/methodology/approach: Ceramic preforms were manufactured by the method of sintering of ceramic powder. The preform material consists of powder Condea Al2O3 CL 2500, however, as the forming factor of the structure of canals and pores inside the ceramic agglomerated framework the carbon fibers Sigrafil C10 M250 UNS were used. Then ceramic preforms were infiltrated with liquid EN AC - AlSi12 aluminium alloy. Stereological and structure investigations of obtained composite materials were made on light microscope. Findings: It was proved that developed technology of manufacturing of composite materials with pore ceramic Al2O3 infiltration ensures expected structure and can be used in practice. Practical implications: The developed technology allows to obtain method's elements locally reinforced and composite materials with precise shape mapping. Originality/value: The received results show the possibility to obtaining the new composite materials being the cheaper alternative for other materials based on the ceramic fibers.
EN
Purpose: The purpose of this work is to elaborate the method of manufacturing of composite materials based on porous ceramic preforms infiltrated by eutectic aluminium alloy. Design/methodology/approach: The material for investigations was fabricated by pressure infiltration method of ceramic porous preforms. The eutectic aluminium alloy EN AC-AlSi12 was use as a matrix while as reinforcement were used ceramic preforms fabricated by sintering of Al2O3 Alcoa CL 2500 powder with addition of pore forming agents as carbon fibres Sigrafil C10 M250 UNS manufactured by SGL Carbon Group company. The observations of the structure were made on the light microscope and in the scanning electron microscope. EDS and XRD analysis of obtained composite materials have been also made. Findings: The developed technology of manufacturing of composite materials with the pore ceramic Al2O3 infiltration ensures expected structure and can be used in practice. Practical implications: The composite materials made by the developed method can find application as the alternative material for elements fabricated from light metal matrix composite material reinforced with ceramic fibrous preforms. Originality/value: The obtained results show the possibility of manufacturing the composite materials by the pressure infiltration method of porous sintered framework based on the ceramic particles with liquid aluminium alloy.
PL
W pracy przedstawiono metodę wytwarzania porowatych szkieletów ceramicznych polegającą na spiekaniu proszku Al2O3 z dodatkiem formującym wewnętrzną strukturę porów i kanalików. Otrzymane półfabrykaty stosuje się jako wzmocnienie w produkcji nowoczesnych materiałów kompozytowych metodą infiltracji ciśnieniowej.
EN
The paper presents method of manufacturing the porous preforms by sintering of Al2O3 powder with addition of pore forming agent. Obtained semi-finished products are used as reinforcement in MMC's manufacturing by infiltration method.
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