CN103018160A - Flexure testing method and flexure testing device for quantitatively characterizing interface binding property of thin-film material - Google Patents

Abstract

The invention relates to a flexure testing method and a flexure testing device for quantitatively characterizing the interface binding property of thin-film material and belongs to the technical field of property characterization of experimental mechanics and material mechanics. The method is characterized in that uniaxial compression is performed to a sample in the axial direction through a universal material testing machine, and the stress strain values of the sample are recorded; meanwhile, the cross section of the sample is observed synchronously in real time through a CCD camera during the loading process, and stripping characteristics such as critical stress, deflexion and crack length can be recorded in real time during the flexure process; and a relation between the coating and plating-substrate stress strain history and the stripping characteristics is established to characterizing the interface binding property of the coating and plating-substrate. According to the device, the CCD camera, a monitor, an image processing card, a computer, a data processing card, a load sensor and the universal material testing machine are connected in sequence. The invention has the advantages of simple principle, simplicity in sample preparation, clear model, easiness in operation, and the like.

Description

Flexing method of testing and the device of quantitatively characterizing membraneous material interfacial combined function

Technical field

The present invention relates to a kind of flexing method of testing and device of quantitatively characterizing membraneous material interfacial combined function, belong to Experimental Mechanics and material mechanical performance characterization technique field.

Background technology

Develop rapidly along with science and technology, film/substrate system widespread use in surface modification and material science, membraneous material is in the process of using, owing to exist difference with base material at aspects such as micromechanisms, thereby under the various complex environments such as mechanical load, thermal force, can show the mismatch of stress, strain, finally can cause the inefficacy of Coating Materials.During engineering was used, film/typical failure mode of substrate system is: film or coating were peeled off from substrate.The service life that whether is well determining to a great extent this material of film/substrate interface combination, so the sign of interfacial combined function has very important significance to the practical application of material.

The sign of the interfacial combined function of film/base material is the basis of Study of Thin membrane interface inefficacy mechanism and its inefficacy of prevention, it relates to the cross disciplines such as material, mechanics, physics, the complicacy of film Problem of Failure, the diversity of failure phenomenon and be difficult to predictability is so that the sign of film interface bonding properties becomes generally acknowledged knotty problem.Internationally famous scholar Evans, Hutchinson, Nix etc. have made outstanding contribution in this field, at home, country has also subsidized a plurality of project of national nature science fund project and has carried out the research work relevant with film interface, but up to the present, the sign of the bonding properties of film still is in theoretical and experimental exploring stage.The quantitatively characterizing of film substrate interface bonding properties is the target of the consistent pursuit with the user of numerous researchers, but because the diversity of film kind and thin film technique, and the effort of pursuing single characterization parameter and characterizing method is manque sign still so far.In some national standards, even have to recommend to judge the firm degree that film is combined with substrate with simple number of bends.This not only allows engineers at a loss as to what to do, also makes researchers feel blushing with shame.

The method that characterizes at present film/base material interfacial combined function nearly more than 200 is planted, and such as pulling method, scarification, stripping method, indentation method, bulge method etc., but does not also have a kind of characterizing method of standard to be suitable for various films/base material system.Pulling method be applicable to weak interface crisp/tough, crisp/crisp system, only just meaningful during less than cohesive strength at interface bond strength.Indentation method is applicable to brittle diaphragm/stiff base, brittle diaphragm/fragility base material system, the sign of more theoretic mechanism, interface bond strength and various factors are on impact of critical load etc., if these problems can not finely solve, the application of indentation method will be restricted.Stripping method is applicable to brittle diaphragm and toughness film, although easily row directly perceived is difficult to extract Interface Crack expansion energy.Although the interfacial combined function of the measurement film that the bulge method can be quantitative, its sample preparation be difficulty relatively, strengthened the difficulty of experiment.Demand the interfacial combined function that a kind of characterizing method comes quantitatively characterizing film-substrate system urgently.

Summary of the invention

For the prior art deficiency, the invention provides a kind of flexing method of testing and device of quantitatively characterizing membraneous material interfacial combined function.

A kind of flexing method of testing of quantitatively characterizing membraneous material interfacial combined function, its concrete steps are as follows:

A. prepare plating coated layer sample to be measured, with sample not the face of plating with sand papering to mirror-smooth;

B. with the sample holder of the plating coated layer to be measured for preparing on universal testing machine, and the CCD camera aimed at the xsect of sample to be tested, regulate position and the focal length of CCD camera, make sample to be tested become clearly image in the centre of CCD viewing field of camera;

C. sample is carried out axial uniaxial compression, the ess-strain numerical value of universal testing machine real time record sample, by the CCD camera xsect of sample in the loading procedure is carried out synchronous real-time monitored, the release characteristics of limit stress, amount of deflection and crack length in the real time record flexing process simultaneously;

D. the relation between coated layer-base stress strain history and the release characteristics set up characterizes the interfacial combined function of coated layer-substrate; The energy release rate G at interface can be calculated by following formula during the coated layer flexing:

$\frac{\mathrm{<figure-callout\; id="0"\; label="G\; G"\; filenames="HDA00002558354700011.png,HDA00002558354700021.png"\; state="\{\{state\}\}">G</figure-callout>}}{G_{}}=(1+3\frac{{\mathrm{\&sigma;}}_{\mathrm{cr}}}{{\mathrm{\&sigma;}}_0})(1-\frac{{\mathrm{\&sigma;}}_{\mathrm{cr}}}{{\mathrm{\&sigma;}}_0}),$ ${\mathrm{<figure-callout\; id="0"\; label="G"\; filenames="HDA00002558354700011.png,HDA00002558354700021.png"\; state="\{\{state\}\}">G</figure-callout>}}_0=\frac{(1-{\mathrm{\&upsi;}}_f^2){\mathrm{h\&sigma;}}_0^2}{{2E}_f};$

E wherein _fBe the elastic modulus of coated layer, unit is Pa, υ _fBe Poisson ratio, h is the thickness of coated layer, and unit is m, G ₀Be the strain energy rate in the plane strain situation, unit is J/m ², σ ₀For being applied to the stress in the coated layer in the loading procedure, unit is Pa, σ _CrBe applied to limit stress in the coated layer when just having begun flexing occurs for coated layer, unit is Pa;

Corresponding phase angle ψ is:

$\tan \mathrm{\&psi;}=\frac{4\cos \mathrm{\&omega;}+\sqrt{3}\mathrm{\&xi;}\sin \mathrm{\&omega;}}{-4\sin \mathrm{\&omega;}+\sqrt{3}\mathrm{\&xi;}\cos \mathrm{\&omega;}}$

Wherein ω is the material phase-displacement angle, and unit is ° that ξ is a nondimensionalization function of flexing amount of deflection.The mismatch parameter α of ω and coated layer and base material, β is relevant, and according to α, the β value is different, and the value of ω is respective change also, and concrete value condition details see the following form:

Table 1 ω and α, the β relation table

α, β, ξ, σ _CrCalculate with following formula:

$\mathrm{\&alpha;}=\frac{{\stackrel{\&OverBar;}{E}}_f-{\stackrel{\&OverBar;}{E}}_s}{{\stackrel{\&OverBar;}{E}}_f+{\stackrel{\&OverBar;}{E}}_s},\mathrm{\&beta;}=\frac{1}{2}\frac{{\mathrm{\&mu;}}_f(1-{2\mathrm{\&upsi;}}_s)-{\mathrm{\&mu;}}_s(1-{2\mathrm{\&upsi;}}_f)}{{\mathrm{\&mu;}}_f(1-{\mathrm{\&upsi;}}_s)+{\mathrm{\&mu;}}_s(1-{\mathrm{\&upsi;}}_f)}$

${\stackrel{\&OverBar;}{E}}_f=\frac{E_f}{1-{\mathrm{\&upsi;}}_{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002558354700021.png"\; state="\{\{state\}\}">f</figure-callout>}}^2},{\stackrel{\&OverBar;}{E}}_s=\frac{E_s}{1-{\mathrm{\&upsi;}}_{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA00002558354700021.png"\; state="\{\{state\}\}">s</figure-callout>}}^2}$

$\mathrm{\&xi;}=\frac{{\mathrm{\&omega;}}_{\max }}{h}=\sqrt{\frac{4}{3}(\frac{{\mathrm{\&sigma;}}_0}{{\mathrm{\&sigma;}}_{\mathrm{cr}}}-1)}$

${\mathrm{\&sigma;}}_{\mathrm{cr}}=\frac{{\mathrm{\&pi;}}^2}{12}\frac{E_f}{1-{\mathrm{\&upsi;}}_f^2}{\left(\frac{h}{b}\right)}^2$

Wherein

Be respectively the elastic modulus of coated layer and substrate in the plane strain situation, unit is Pa, υ _f, υ _sBe respectively the Poisson ratio of coated layer and substrate, μ _f, μ _sBe respectively the modulus of shearing of coated layer and substrate, unit is Pa, E _f, E _sBe respectively the elastic modulus of coated layer and substrate, unit is Pa, and ξ is a nondimensionalization function of flexing amount of deflection, ω _MaxBe the amount of deflection of sample coated layer flexing central point, unit is m, and h is the thickness of coated layer, and unit is m, σ ₀Be the stress in the coated layer in the loading procedure, unit is Pa, σ _CrLimit stress when just having begun flexing occurs for coated layer, unit is Pa, and the crackle when b is flexing half is long, and unit is m.

The base length of described plating coated layer sample to be measured is 10mm, and width is 5mm, and thickness is 5mm.

The frequency of taking pictures of described CCD camera is 1 ~ 2 second/.

The loading mode of described universal testing machine is that load loads, and loading speed is 3000N/min, and the maximum displacement of compression is 1 ~ 2mm.

A kind of flexing proving installation of quantitatively characterizing membraneous material interfacial combined function, its CCD camera, monitor, video processing board-card, computing machine, data processing card, load transducer link to each other in turn with universal testing machine.

The frequency of taking pictures of described CCD camera is 1 ~ 2 second/.

The loading mode of described universal testing machine is that load loads, and loading speed is 3000N/min, and the maximum displacement of compression is 1 ~ 2mm.

Beneficial effect of the present invention is:

The present invention utilizes universal testing machine that sample is carried out axial uniaxial compression, thereby so that coated layer at the interface in conjunction with weakness generation flexing, by the CCD camera xsect of sample in the loading procedure is carried out synchronous real-time monitored simultaneously, the relation between coated layer-base stress strain history and the release characteristics set up characterizes the interfacial combined function of coated layer-substrate, has that principle is simple, simple, the advantages such as model is clear, easy operating of sample preparation.

Description of drawings

Fig. 1 is apparatus of the present invention structural representation;

Fig. 2 is CCD camera observation area synoptic diagram;

Fig. 3 is the stress-strain diagram of sample pressurized among the embodiment;

Fig. 4 is the picture of sample real time record in Failure under Uniaxial Compression among the embodiment; Wherein Fig. 4 a is the picture when in the sample pressurized process flexing not occuring, and Fig. 4 b is the picture of sample when just flexing having occured, and Fig. 4 c is the picture of sample flexing expansion; Fig. 4 a, 4b, the A in the 4c difference corresponding diagram 3, B, the state that D is 3.

Number in the figure: 1-universal testing machine; The 2-cold light lamp source; The 3-CCD camera; The 4-monitor; The 5-video processing board-card; The 6-computing machine; The 7-data processing card; The 8-load transducer; 9-universal testing machine pressure head; 10-universal testing machine bearing; The coated layer part of 11-sample; The base part of 12-sample.

Embodiment

The invention provides a kind of flexing method of testing and device of quantitatively characterizing membraneous material interfacial combined function, the present invention will be further described below in conjunction with the drawings and specific embodiments.

A kind of flexing method of testing of quantitatively characterizing membraneous material interfacial combined function, its concrete steps are as follows:

A. prepare plating coated layer sample to be measured, with sample not the face of plating with sand papering to mirror-smooth;

B. with the sample holder of the plating coated layer to be measured for preparing on universal testing machine, and the CCD camera aimed at the xsect of sample to be tested, regulate position and the focal length of CCD camera, make sample to be tested become clearly image in the centre of CCD viewing field of camera;

C. sample is carried out axial uniaxial compression, the ess-strain numerical value of universal testing machine real time record sample, by the CCD camera xsect of sample in the loading procedure is carried out synchronous real-time monitored, the release characteristics of limit stress, amount of deflection and crack length in the real time record flexing process simultaneously;

D. the relation between coated layer-base stress strain history and the release characteristics set up characterizes the interfacial combined function of coated layer-substrate; The energy release rate G at interface can be calculated by following formula during the coated layer flexing:

$\frac{\mathrm{<figure-callout\; id="0"\; label="G\; G"\; filenames="HDA00002558354700011.png,HDA00002558354700021.png"\; state="\{\{state\}\}">G</figure-callout>}}{G_{}}=(1+3\frac{{\mathrm{\&sigma;}}_{\mathrm{cr}}}{{\mathrm{\&sigma;}}_0})(1-\frac{{\mathrm{\&sigma;}}_{\mathrm{cr}}}{{\mathrm{\&sigma;}}_0}),$ ${\mathrm{<figure-callout\; id="0"\; label="G"\; filenames="HDA00002558354700011.png,HDA00002558354700021.png"\; state="\{\{state\}\}">G</figure-callout>}}_0=\frac{(1-{\mathrm{\&upsi;}}_f^2){\mathrm{h\&sigma;}}_0^2}{{2E}_f};$

E wherein _fBe the elastic modulus of coated layer, unit is Pa, υ _fBe Poisson ratio, h is the thickness of coated layer, and unit is m, G ₀Be the strain energy rate in the plane strain situation, unit is J/m ², σ ₀For being applied to the stress in the coated layer in the loading procedure, unit is Pa, σ _CrBe applied to limit stress in the coated layer when just having begun flexing occurs for coated layer, unit is Pa;

Corresponding phase angle ψ is:

$\tan \mathrm{\&psi;}=\frac{4\cos \mathrm{\&omega;}+\sqrt{3}\mathrm{\&xi;}\sin \mathrm{\&omega;}}{-4\sin \mathrm{\&omega;}+\sqrt{3}\mathrm{\&xi;}\cos \mathrm{\&omega;}}$

Wherein ω is the material phase-displacement angle, and unit is ° that ξ is a nondimensionalization function of flexing amount of deflection.The mismatch parameter α of ω and coated layer and base material, β is relevant, and according to α, the β value is different, and the value of ω is respective change also, and concrete value condition details see the following form:

Table 1 ω and α, the β relation table

α, β, ξ, σ _CrCalculate with following formula:

$\mathrm{\&alpha;}=\frac{{\stackrel{\&OverBar;}{E}}_f-{\stackrel{\&OverBar;}{E}}_s}{{\stackrel{\&OverBar;}{E}}_f+{\stackrel{\&OverBar;}{E}}_s},\mathrm{\&beta;}=\frac{1}{2}\frac{{\mathrm{\&mu;}}_f(1-{2\mathrm{\&upsi;}}_s)-{\mathrm{\&mu;}}_s(1-{2\mathrm{\&upsi;}}_f)}{{\mathrm{\&mu;}}_f(1-{\mathrm{\&upsi;}}_s)+{\mathrm{\&mu;}}_s(1-{\mathrm{\&upsi;}}_f)}$

${\stackrel{\&OverBar;}{E}}_f=\frac{E_f}{1-{\mathrm{\&upsi;}}_{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002558354700021.png"\; state="\{\{state\}\}">f</figure-callout>}}^2},{\stackrel{\&OverBar;}{E}}_s=\frac{E_s}{1-{\mathrm{\&upsi;}}_{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA00002558354700021.png"\; state="\{\{state\}\}">s</figure-callout>}}^2}$

$\mathrm{\&xi;}=\frac{{\mathrm{\&omega;}}_{\max }}{h}=\sqrt{\frac{4}{3}(\frac{{\mathrm{\&sigma;}}_0}{{\mathrm{\&sigma;}}_{\mathrm{cr}}}-1)}$

${\mathrm{\&sigma;}}_{\mathrm{cr}}=\frac{{\mathrm{\&pi;}}^2}{12}\frac{E_f}{1-{\mathrm{\&upsi;}}_f^2}{\left(\frac{h}{b}\right)}^2$

Wherein

Be respectively the elastic modulus of coated layer and substrate in the plane strain situation, unit is Pa, υ _f, υ _sBe respectively the Poisson ratio of coated layer and substrate, μ _f, μ _sBe respectively the modulus of shearing of coated layer and substrate, unit is Pa, E _f, E _sBe respectively the elastic modulus of coated layer and substrate, unit is Pa, and ξ is a nondimensionalization function of flexing amount of deflection, ω _MaxBe the amount of deflection of sample coated layer flexing central point, unit is m, and h is the thickness of coated layer, and unit is m, σ ₀Be the stress in the coated layer in the loading procedure, unit is Pa, σ _CrLimit stress when just having begun flexing occurs for coated layer, unit is Pa, and the crackle when b is flexing half is long, and unit is m.

The base length of described plating coated layer sample to be measured is 10mm, and width is 5mm, and thickness is 5mm.

The frequency of taking pictures of described CCD camera is 1 ~ 2 second/.

The loading mode of described universal testing machine is that load loads, and loading speed is 3000N/min, and the maximum displacement of compression is 1 ~ 2mm.

A kind of flexing proving installation of quantitatively characterizing membraneous material interfacial combined function, its CCD camera 3, monitor 4, video processing board-card 5, computing machine 6, data processing card 7, load transducer 8 and universal testing machine 1 link to each other in turn.

The frequency of taking pictures of described CCD camera 3 is 1 ~ 2 second/.

The loading mode of described universal testing machine 1 is that load loads, and loading speed is 3000N/min, and the maximum displacement of compression is 1 ~ 2mm.

Embodiment 1

Consider a concrete situation: nickel film-mild carbon steel system, the thickness h of nickel film=6 * 10 are selected in coated layer-substrate ^-5M, elastic modulus are E _f=2.2 * 10 ¹¹Pa, the elastic modulus E of mild carbon steel substrate _s=2 * 10 ¹¹Pa, Poisson ratio υ _f=υ _s=0.3.Critical Buckling stress σ _Cr=4.46 * 10 ⁸Pa, the stress σ during loading in the film ₀=6 * 10 ⁸Pa, for nickel film-mild carbon steel substrate system, α ≈ 0, β ≈ 0 can obtain ω=52.1 °, the amount of deflection ω of sample coated layer flexing central point by the data in the table _Max=6.7 * 10 ^-5The above-mentioned formula of m substitution obtains the interface bonding energy G=37.1J/m of nickel film-mild carbon steel substrate system ², phase angle Ψ=-637 °.

Claims (7)

1. the flexing method of testing of a quantitatively characterizing membraneous material interfacial combined function is characterized in that concrete steps are as follows:

A. prepare plating coated layer sample to be measured, with sample not the face of plating with sand papering to mirror-smooth;

B. with the sample holder of the plating coated layer to be measured for preparing on universal testing machine, and the CCD camera aimed at the xsect of sample to be tested, regulate position and the focal length of CCD camera, make sample to be tested become clearly image in the centre of CCD viewing field of camera;

C. sample is carried out axial uniaxial compression, the ess-strain numerical value of universal testing machine real time record sample, by the CCD camera xsect of sample in the loading procedure is carried out synchronous real-time monitored, the release characteristics of limit stress, amount of deflection and crack length in the real time record flexing process simultaneously;

D. the relation between coated layer-base stress strain history and the release characteristics set up characterizes the interfacial combined function of coated layer-substrate; The energy release rate G at interface can be calculated by following formula during the coated layer flexing:

$\frac{G}{G_0}=(1+3\frac{{\mathrm{\&sigma;}}_{\mathrm{cr}}}{{\mathrm{\&sigma;}}_0})(1-\frac{{\mathrm{\&sigma;}}_{\mathrm{cr}}}{{\mathrm{\&sigma;}}_0})$ ， $G_0=\frac{(1-{\mathrm{\&upsi;}}_f^2)h{\mathrm{\&sigma;}}_0^2}{2E_f}$ ；

E wherein _fBe the elastic modulus of coated layer, unit is Pa, υ _fBe Poisson ratio, h is the thickness of coated layer, and unit is m, G ₀Be the strain energy rate in the plane strain situation, unit is J/m ², σ ₀For being applied to the stress in the coated layer in the loading procedure, unit is Pa, σ _CrBe applied to limit stress in the coated layer when just having begun flexing occurs for coated layer, unit is Pa;

Corresponding phase angle ψ is:

$\tan \mathrm{\&psi;}=\frac{4\cos \mathrm{\&omega;}+\sqrt{3}\mathrm{\&xi;}\sin \mathrm{\&omega;}}{-4\sin \mathrm{\&omega;}+\sqrt{3}\mathrm{\&xi;}\cos \mathrm{\&omega;}}$

Wherein ω is the material phase-displacement angle, and unit is ^o, ξ is a nondimensionalization function of flexing amount of deflection.

2. method according to claim 1, it is characterized in that: the base length of described plating coated layer sample to be measured is 10 mm, and width is 5 mm, and thickness is 5 mm.

3. method according to claim 1 is characterized in that: the frequency of taking pictures of described CCD camera is 1 ~ 2 second/.

4. method according to claim 1 is characterized in that: the loading mode of described universal testing machine is that load loads, and loading speed is 3000 N/min, and the maximum displacement of compression is 1 ~ 2 mm.

5. the flexing proving installation of a quantitatively characterizing membraneous material interfacial combined function, it is characterized in that: CCD camera (3), monitor (4), video processing board-card (5), computing machine (6), data processing card (7), load transducer (8) and universal testing machine (1) link to each other in turn.

6. device according to claim 5 is characterized in that: the frequency of taking pictures of described CCD camera (3) is 1 ~ 2 second/.

7. device according to claim 5 is characterized in that: the loading mode of described universal testing machine (1) is that load loads, and loading speed is 3000 N/min, and the maximum displacement of compression is 1 ~ 2 mm.

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