Wpływ chropowatości powierzchni i twardości podłoża na pomiar twardości cienkich warstw.

• Autorzy: Kot M. , Rakowski W.

Warianty tytułu

EN

The effect of surface roughness and substrate hardness on thin coating hardness measurements.

• Języki publikacji: PL

Abstrakty

PL

Twardość powierzchni jest jednym z fundamentalnych parametrów zarówno w mechanice kontaktu, jak i w teorii tarcia, a także podstawowym parametrem w prognozowaniu trwałości eksploatacyjnej elementów węzłów kinematycznych maszyn. Pomimo coraz powszechniejszego stosowania powłok na powierzchniach roboczych elementów par tribologicznych wiarygodność znanych metod wyznaczania ich twardości jest nadal dyskusyjna. W artykule przedstawiono metodę określania twardości cienkich warstw polegającą na wykonaniu serii pomiarów twardości powierzchni przy wzrastających głębokościach penetracji, a następnie analitycznym wyznaczeniu twardości samej warstwy powierzchniowej. Eksperymentalną weryfikację zaproponowanej metody przeprowadzono na próbkach: TiN na stali narzędziowej oraz warstwy diamentopodobnej (DLC-diamond like carbon) na krzemie. Pomiary mikrotwardości wykonano przy użyciu Micro-Combi-Testera firmy CSEM.

EN

Thin coatings are increasingly being applied in many advanced products. Examples of application are protective overcoats of recording films in optical storage disks, thin layers in multilayer capacitors. In mechanical engineering the coatings are used in several different applications, e.g. in cutting tools, dies and other tribological application, as protective films and corrosion resistant coatings. The estimation of the mechanical properties of thin films on substrates is still an area of considerable discussion. The hardness is one of the key mechanical properties of a number of coated systems. It has been measured using a variety of experimental techniques ranging from traditional macro-Vickers indentation to ultra-low-load depth-sensing nanoindentation. However, since the contact response of coated system will vary with contact severity and scale, it is important to develop methods of hardness measurement, which allow performance over a suitably wide range of scales to be successfully predicted. The analysis of indentation results is very ambiguous because of complex indentation stress field beneath the indenter, particularly in the case of multilayer coating systems and gradient materials. There is general agreement, that at contact scales of dimensions less than the coating thickness (t) the coating dominates the system response, what it means that to obtain intrinsic hardness value for thin-film, the indentation depth (h) should be ten times smaller than the film thickness. At contact scales which are very large compared with t, the substrate dominates and with a mixed response occuring at intermediate scales. However, besides of the essential upper bound of indentation depth it exists a lower bound, which arises from surface roughness. The micro- and nanoindentation techniques are very sensitive to the surface roughness. In general, it is recommended the indentation depth larger than fifth times of RMS. The surface roughness of a number of coated systems is high in relation to the thickness of coating, what is critical in selection of the appropriate indentation depth. The purpose of this paper is a method for evaluation of intrinsic coating hardness in the cases, when is not possible to fulfil a condition, that the indentation depth should be ten times smaller than the film thickness, as it is for thin coatings with relative roughness. In the case of hard, thin and rough coating on softer substrate the method consists of analysis of the force-displacement data, obtained from series of tests, with wide range of the different relative indentation depth (0,05

Słowa kluczowe

PL

tribologia; cienka warstwa; twardość warstwy; twardość podłoża

EN

tribology; thin film; film hardness; substrate hardness

• Wydawca: Komitet Budowy Maszyn PAN
• Czasopismo: Zagadnienia Eksploatacji Maszyn
• Rocznik: 2005
• Tom: Vol. 40, nr 2
• Strony: 17--30
• Opis fizyczny: Bibliogr. 17 poz.

Twórcy

autor

Kot M.

• Akademia Górniczo-Hutnicza, Wydział Inżynierii Mechanicznej i Robotyki, 30-065 Kraków, al. Mickiewicza 30

autor

Rakowski W.

• Akademia Górniczo-Hutnicza, Wydział Inżynierii Mechanicznej i Robotyki, 30-065 Kraków, al. Mickiewicza 30

Bibliografia

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