Wyniki wyszukiwania - BazTech

1

Multiscale assessment of additively manufactured free-form surfaces

Gogolewski Damian

Metrology and Measurement Systems

|

2023

|

Vol. 30, nr 1

157--168

EN

The article reviews the results of experimental tests assessing the impact of process parameters of additive manufacturing technologies on the geometric structure of free-form surfaces. The tests covered surfaces manufactured with the Selective Laser Melting additive technology, using titanium-powder-based material (Ti6Al4V) and Selective Laser Sintering from polyamide PA2200. The evaluation of the resulting surfaces was conducted employing modern multiscale analysis, i.e., wavelet transformation. Comparative studies using selected forms of the mother wavelet enabled determining the character of irregularities, size of morphological features and the indications of manufacturing process errors. The tests provide guidelines and allow to better understand the potential in manufacturing elements with complex, irregular shapes.

2

Assessment of surface waviness of casting patterns made using 3D printing technologies

Zmarzły Paweł, Gogolewski Damian, Kozior Tomasz

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2023

|

Vol. 71, nr 1

art. no. e144585

EN

The application of 3D printers significantly improves the process of producing foundry patterns in comparison to traditional methods of their production. It should be noted that the quality of the surface texture of the foundry pattern is crucial because it affects the quality of the casting mold and eventually the finished casting. In most studies, the surface texture is examined by analyzing the 2D or 3D roughness parameters. This is a certain limitation because, in the case of 3D printing, the influence of technological parameters is more visible for irregularities of a longer range, such as surface waviness. In the paper, the influence of the 3D printing layer thickness on the formation of waviness of the surface of casting patterns was analyzed. Three 3D printers, differing in terms of printing technology and printing material, were tested: PJM (PolyJet Matrix), FDM (fused deposition modeling) and SLS (selective laser sintering). In addition, the surface waviness of patterns manufactured with traditional methods was analyzed. Surface waviness has been measured using the Form Talysurf PGI 1200 measuring system. Preliminary results of the research showed that the layer thickness significantly influences the values of waviness parameters of the surface in the casting patterns made with FDM, PJM and SLS additive technologies. The research results indicated that the smallest surface waviness as defined by parameters Wa, Wq and Wt was obtained for patterns printed using the PJM technology, while the highest was noted when using the FDM technology.

3

An assessment of applicability of the two-dimensional wavelet transform to assess the minimum chip thickness determination accuracy

Gogolewski Damian, Makieła Włodzimierz, Nowakowski Łukasz

Metrology and Measurement Systems

|

2020

|

Vol. 27, nr 4

659--672

EN

The objective of the study was to assess the potential use of optical measuring instruments to determine the minimum chip thickness in face milling. Images of scanned surfaces were analyzed using mother wavelets. Filtration of optical signals helped identify the characteristic zones observed on the workpiece surface at the beginning of the cutting process. The measurement data were analyzed statistically. The results were then used to estimate how accurate each measuring system was to determine the minimum uncut chip thickness. Also, experimental verification was carried out for each mother wavelet to assess their suitability for analyzing surface images.

4

Ocena wpływu gęstości próbkowania poziomego na proces dekompozycji falkowej

Makieła Włodzimierz, Gogolewski Damian

Mechanik

|

2019

|

R. 92, nr 1

32--34

PL

Oceniono znaczenie gęstości próbkowania poziomego oraz poziomu dekompozycji falkowej w aspekcie zastosowania poszczególnych funkcji falkowych do podziału badanego profilu pierwotnego na składowe nierówności powierzchni. Pomiary profili powierzchni wykonano za pomocą profilometru stykowego, z określoną gęstością próbkowania. Analizie poddano dwa typy powierzchni: wytworzoną techniką przyrostową oraz po obróbce szlifowaniem.

EN

The paper assesses the impact of horizontal sampling density and level of wavelet decomposition in the aspect of applying mother wavelet to divide components of surface texture. Measurements of surface profiles were made using a contact profilometer applying a specific sample density. Two types of surfaces were prepared: using additive technology and grinding.

5

Methods of comparison of surface texture based on fractal dimension and Hotelling’s T2 test

Gogolewski Damian

Journal of Machine Engineering

|

2019

|

Vol. 19, No. 4

82--90

EN

Comparative analysis of the surface texture of machine parts can be successfully carried out using statistical tests. The paper presents a methodology of method used to compare the surface texture by applying Hotelling’s T2 test as well as a method used to evaluate surface topography by applying fractal dimension. The tests were carried out on samples produced with the use of face milling process for four types of materials. The following types of steel were used: 40HM, C45, NC6 and WCL. For each type of material, four areas were machined with the same machining parameters. Based on these results a decision was made whether the surfaces, despite the same machining conditions, were significantly different from each other. Furthermore, the analysis indicated that the fractal dimension enabled to characterise signal irregularities in quantitative and qualitative way.