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Number of results: 4
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Abstract

Basing on experimental data, the possibility of consolidating side products of turning, milling and drilling of aluminum alloys into the form and properties of solids metals using low-temperature KoBo extrusion method has been assessed. Research regarding mechanical and structural properties of the final products revealed their total consolidation and proved their compatibility with requirements for products made of bulk billets. Importantly, the chips consolidation process does not require high or even raised temperature, which significantly reduces the unfavorable phenomenon of chips oxidation and its negative influence on the structure and mechanical properties of products. A very good effect of chips compaction has been proved by KoBo method, which has been confirmed by relatively slightly different mechanical properties of the material after recycling compared with the bulk one. Among currently applied techniques of consolidation of dispersed fractions in a solid state (leaving the melting stage out), the KoBo method seems an innovative way of utilizing metallic chips, as it enables a cold deformation process.

The paper presents investigations using 2024 and 7075 aluminum alloys chips from manufacturing process, formed into briquettes and deformed under conditions of KoBo extrusion process, which enables to obtain long product by cold forming. The final product characterized by good microstructures, mechanical features and low cost of production.

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Authors and Affiliations

B. Pawłowska
R.E. Śliwa
ORCID: ORCID
M. Zwolak
ORCID: ORCID
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Abstract

The paper presents selected results of KOBO extrusion process of circular profile ϕ10 mm from aluminum alloy 2099. The main aim of the performed research was to determine the influence of the oscillation frequency of a die on the magnitude of extrusion force. During the process such parameters, as extrusion force, rate of stem and frequency of die oscillation were recorded; oscillating angle of a die was constant and equal ±8°. The die oscillation frequency was changeable in performed tests in the range of 2 ÷ 7 Hz. The obtained results allowed to determine the relation between the maximum extrusion force and the die oscillation frequency during extrusion of aluminum 2099 alloy.

The paper focuses on the experimental analysis of mechanical characteristics of the KOBO process. Basing on the recorded force versus stem position, three stages of KOBO extrusion process were determined, i.e. initialization, stabilization and uniform extrusion. Points separating these stages are two inflection points of recorded diagram. The analysis of each stage was made basing on the results of force diagrams and literature data.

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Authors and Affiliations

T. Balawender
ORCID: ORCID
M. Zwolak
ORCID: ORCID
Ł. Bąk
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Abstract

This study aims to determine optimal forming parameters for Incremental Sheet Forming process Commercially Pure titanium Grade 2 sheets in terms of formability improvement, force reduction, and efficiency of forming. Based on the central composite design, data were collected during 20 runs and then variation analysis was performed. The experiments were performed on a 3 axis CNC milling machine equipped with a Kistler dynamometer plate. Subsequently, regression models have been developed to describe process responses by input factors. As crucial parameters, the relative velocity and step size of the tool that affect the forming force and the height of the fracture have been determined. Finally, the application of optimization algorithm has emerged optimal input factors in terms of selected multi-criteria goal. The results of this study suggest that there is a process window that allows the formation of 45° wall angle drawpieces of commercially pure titanium Grade 2.
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Authors and Affiliations

M. Szpunar
1
ORCID: ORCID
T. Trzepieciński
1 2
ORCID: ORCID
R. Ostrowski
3
ORCID: ORCID
M. Zwolak
3
ORCID: ORCID

  1. Rzeszow University of Technology, Doctoral School of Engineering and Technical Sciences, 8 Powst. Warszawy Av., 35-959, Rzeszów, Poland
  2. Rzeszow University of Technology, Department of Manufacturing and Production Engineering, 12 Powst. Warszawy Av., 35-959, Rzeszów, Poland
  3. Rzeszow University of Technology, Department of Materials Forming and Processing, 12 Powst. Warszawy Av., 35-959, Rzeszów, Poland
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Abstract

The paper presents the possibility of using FSW technology for joining elements of a landing gear beam of the M28 aircraft. The FSW process was performed on a 4-axis numerical machine under industrial conditions. However, before welding was carried out under industrial conditions, preliminary experimental tests were carried out under laboratory conditions. Preliminary research was carried out for AA2024-T3 aluminum sheets of 1 mm and 3 mm in thickness, joined in a lap configuration. The influence of technological and geometric parameters of the process on the quality and strength of the weld was examined. Sheet metal arrangement was analyzed. Tests were carried out for two configurations. The first of which with 1 mm sheet on the top and 3 mm sheet on the bottom and in reverse order. It has been shown that setting a thicker plate on the top gives a 40% better strength. The microhardness and microstructure of the weld were tested. During the laboratory tests, low-cycle fatigue tests of the FSW lap joint were performed. It has been shown that the FSW method can be an alternative to the riveting process in the production of aviation structure elements.

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Authors and Affiliations

P. Myśliwiec
R.E. Śliwa
ORCID: ORCID
R. Ostrowski
ORCID: ORCID
M. Bujny
M. Zwolak
ORCID: ORCID

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