Summary of the invention
The object of the present invention is to provide thickness controlled, a kind of Mg alloy surface with good corrosion energy is prepared the method for yttrium/silicon nitride composite coating material.
The present invention includes following steps:
1) substrate pretreatment;
2) target pre-sputtering;
3) d.c. sputtering deposition transition metal Y film;
4) RF-reactively sputtered titanium deposits outer amorphous Si
3n
4film.
In step 1), described substrate pretreatment, can carry out mechanical mill polished finish, ultrasonic cleaning processing, the processing of ion source Bombardment and cleaning successively.Described mechanical mill polished finish can first be ground to surfacing by magnesium alloy on 1000 order SiC silicon carbide papers, is placed in dehydrated alcohol ultrasonic cleaning 5min; Then on 2000 order SiC silicon carbide papers, be ground to cut in the same direction, be placed in ethanol ultrasonic cleaning 5min; Then on 5000 order SiC silicon carbide papers, along vertical 2000 order cut directions, grind 90 ~ 120s, be placed in ethanol ultrasonic cleaning 10min; With the diamond polishing cream that particle diameter is 1 μ m and 0.5 μ m, carry out polished finish on polishing disk successively again, polishing disk rotating speed is 600r/min, is polished to surface and is the nearly mirror status of light; Distilled water flushing is placed on ultrasonic cleaning 15min in acetone, is then placed in dehydrated alcohol ultrasonic cleaning 15min, moves to afterwards sample table, puts into cavity, vacuumizes and protects.Described ion source Bombardment and cleaning is processed, and can adopt Hall ion source to clean matrix, and substrate temperature is 250 ℃, regulates Ar flow to 10sccm, and environmental stress is 2.3 * 10
-2pa, regulating bias voltage is-80 ~-100V, and cathodic current is 28.5 ~ 29.5A, and cathode voltage is 16 ~ 18V, and anodic current is 6.8 ~ 7.2A, anode voltage is 56 ~ 58V, cleans 5 ~ 8min.
In step 2) in, described target pre-sputtering, cavity environment temperature can be heated to 120 ~ 150 ℃, magnesium alloy substrate temperature is heated to 250 ℃, pass into Ar gas (purity 99.999%), flow set, at 40sccm, regulates the interior operating pressure of cavity to 1.0Pa, by Y metal targets (purity 99.9%) power regulation to 180 ~ 200W, pre-sputtering 10min; Then direct supply is connected to pure Si target (purity 99.99%), power regulation to 180 ~ 200W, pre-sputtering 10min; To remove the contaminating impurities such as target material surface oxide compound, activation target material surface atom, carries the highly purified while and also improves the sputter rate of target.
In step 3), described d.c. sputtering deposition transition metal Y film, can confirm that cavity environment temperature is 120 ~ 150 ℃, and magnesium alloy substrate temperature is to proceed as follows after 250 ℃: regulate Ar flow to 60sccm, now chamber pressure is 1.50Pa, regulates chamber pressure to 0.30Pa; Rotate sample table, make sample table over against Y metal targets, both distances are 10cm; Target d.c. sputtering power is risen to 250W, opens target plate washer, start timing, sputtering sedimentation certain hour, to thickness be H
1(50 ~ 100nm), closes rapidly target plate washer afterwards, regulates direct supply power to 0W.
In step 4), described RF-reactively sputtered titanium deposits outer amorphous Si
3n
4film, can, after transition metal Y film deposition, proceed as follows: regulate Ar flow to 0sccm, keep 120 ~ 150 ℃ of cavity envrionment temperatures, magnesium alloy substrate temperature is 250 ℃, vacuumizes half an hour; Pass into afterwards high-purity N
2gas (purity 99.999%) and Ar gas, regulating nitrogen flow is 20 ~ 25%, total flux is 60sccm, regulates chamber pressure to 0.30Pa; Rotate sample table, make sample table over against pure Si target, both distances are 8cm; Access radio-frequency power supply, opens target plate washer, and target radio-frequency sputtering power is risen to 500W, starts timing, sputtering sedimentation for some time, to thickness be H
2, total film thickness meets H
1+ H
2=3.00 ± 0.05 μ m, closes rapidly target plate washer afterwards, regulates direct supply power to 0W.
The present invention creatively uses metal Y as transition layer, then RF-reactively sputtered titanium deposited amorphous state Si on the basis of transition layer
3n
4embrane method.Under the conditions such as certain deposition pressure, temperature, gas flow, by changing sputtering time, prepare the thick controlled Y/Si with superpower corrosion resistance of each tunic
3n
4composite coating material.By the electro-chemical test of electrokinetic potential polarization curve and alternating-current impedance and the actual use test of liberation of hydrogen test and salt-fog test, result shows surface coverage Y/Si
3n
4the magnesium alloy of compound coating has good corrosion resistance.
Embodiment
Embodiment 1
1, substrate pretreatment
(1) mechanical mill polished finish is first ground to surfacing by magnesium alloy on 1000 order SiC silicon carbide papers, is placed in dehydrated alcohol ultrasonic cleaning 5min; Then on 2000 order SiC silicon carbide papers, be ground to cut in the same direction, be placed in ethanol ultrasonic cleaning 5min; Then on 5000 order SiC silicon carbide papers, along vertical 2000 order cut directions, grind 90s, be placed in ethanol ultrasonic cleaning 10min; With the diamond polishing cream that particle diameter is 1 μ m and 0.5 μ m, carry out polished finish on polishing disk successively again, polishing disk rotating speed is 600r/min, is polished to surface and is the nearly mirror status of light, distilled water flushing.
(2) ultrasonic cleaning is processed, and is placed in acetone ultrasonic cleaning 15min, is then placed in dehydrated alcohol ultrasonic cleaning 15min, moves to afterwards sample table, puts into cavity, vacuumizes and protects.
(3) ion source Bombardment and cleaning is processed, and adopts Hall ion source to clean matrix, and substrate temperature is 250 ℃, regulates Ar flow to 10sccm, and environmental stress is 2.3 * 10
-2pa, regulates bias voltage to be-80V, and cathodic current is 29.5A, and cathode voltage is 18V, and anodic current is 7.2A, and anode voltage is 58V, cleans 5min.
2, metal Y, pure Si target pre-sputtering
Cavity environment temperature is heated to 120 ℃, and magnesium alloy substrate temperature is heated to 250 ℃, passes into Ar gas (purity 99.999%), flow set is at 40sccm, regulate in cavity operating pressure to 1.0Pa, by Y metal targets (purity 99.9%) power regulation to 180W, pre-sputtering 10min; Then direct supply is connected to pure Si target (purity 99.99%), power regulation is to 180W, pre-sputtering 10min; To remove the contaminating impurities such as target material surface oxide compound, activation target material surface atom, carries the highly purified while and also improves the sputter rate of target.
3, d.c. sputtering deposition transition metal Y film
Confirm that cavity environment temperature is 120 ℃, magnesium alloy substrate temperature is 250 ℃.Regulate Ar flow to 60sccm, now chamber pressure is 1.50Pa, regulates chamber pressure to 0.30Pa; Rotate sample table, make sample table over against Y metal targets, both distances are 10cm; Target d.c. sputtering power is risen to 250W, open target plate washer, start timing, sputtering sedimentation 15s, closes rapidly target plate washer afterwards, regulates direct supply power to 0W.
4, RF-reactively sputtered titanium deposits outer amorphous Si
3n
4film
After transition metal Y film deposition, regulate Ar flow to 0sccm, keep 120 ℃ of cavity envrionment temperatures, magnesium alloy substrate temperature is 250 ℃, normally vacuumizes half an hour; Pass into afterwards high-purity N
2gas (purity 99.999%) and Ar gas, regulating nitrogen flow is 20%, total flux is 60sccm, regulates chamber pressure to 0.30Pa; Rotate sample table, make sample table over against pure Si target, both distances are 8cm; Access radio-frequency power supply, opens target plate washer, and target radio-frequency sputtering power is risen to 500W, starts timing, and sputtering sedimentation 96min, closes rapidly target plate washer afterwards, regulates direct supply power to 0W.
5, Y/Si
3n
4the total film thickness of composite coating material characterizes and adopts Dektak3 Series film thickness measuring instrument, and total film thickness is 2.96 μ m.Fig. 1 is Y/Si
3n
4the GIXRD spectrogram of composite coating material, shows that the coating of preparation is the Y coating with close-packed hexagonal structure, does not occur the diffraction peak of silicon nitride, illustrates that silicon nitride is that non-crystalline state exists.Fig. 2 is the XPS figure of embodiment 1 depth profiling, and surface nitrogen SiClx is compound S i
3n
4.Fig. 3 is the section SEM figure of embodiment 1: (a) show that coating is fine and close, solid matter growth, non-columnar crystal structure; (b) thickness that roughly can find out Y transition layer is 50 ± 5nm.Fig. 4 is embodiment 1 coating binding force test cross-reference figure: (a) embodiment 1 sample before test; (b) sample after test.Experimental standard is with reference to ASTM D3359-02, and result shows, there is a small amount of disbonding at place, point of crossing, but area of infection is less than 5%, illustrates that coating binding force is good.Fig. 5 and Fig. 6 are that the Electrochemical results of embodiment 1: Fig. 5 is electrokinetic potential polarization curve; Fig. 6 is alternating-current impedance, and result shows, with respect to plated film magnesium alloy not, and surface coverage Y/Si
3n
4the magnesium alloy of compound coating has good corrosion resistance.Fig. 7 is the liberation of hydrogen tests in 7 days of embodiment 1, and result shows at duration of test, surface coverage Y/Si
3n
4the magnesium alloy of compound coating shows good corrosion resisting property (hydrogen-separating quantity levels off to zero).Fig. 8 is 15 days salt-fog test cross-reference figure of embodiment 1, and experimental standard is with reference to GBT6461-2002, and defect area is less than 0.5%, protection grading R
p>=8, consistent with test result before, surface coverage Y/Si is described
3n
4the magnesium alloy of compound coating has good corrosion resistance really.
Embodiment 2
1, substrate pretreatment
(1) mechanical mill polished finish is first ground to surfacing by magnesium alloy on 1000 order SiC silicon carbide papers, is placed in dehydrated alcohol ultrasonic cleaning 5min; Then on 2000 order SiC silicon carbide papers, be ground to cut in the same direction, be placed in ethanol ultrasonic cleaning 5min; Then on 5000 order SiC silicon carbide papers, along vertical 2000 order cut directions, grind 100s, be placed in ethanol ultrasonic cleaning 10min; With the diamond polishing cream that particle diameter is 1 μ m and 0.5 μ m, carry out polished finish on polishing disk successively again, polishing disk rotating speed is 600r/min, is polished to surface and is the nearly mirror status of light, distilled water flushing.
(2) ultrasonic cleaning is processed, with embodiment 1.
(3) ion source Bombardment and cleaning is processed, and adopts Hall ion source to clean matrix, and substrate temperature is 250 ℃, regulates Ar flow to 10sccm, and environmental stress is 2.3 * 10
-2pa, regulates bias voltage to be-90V, and cathodic current is 28.5A, and cathode voltage is 16V, and anodic current is 6.5A, and anode voltage is 56V, cleans 8min.
2, metal Y, pure Si target pre-sputtering
Cavity environment temperature is heated to 130 ℃, and magnesium alloy substrate temperature is heated to 250 ℃, passes into Ar gas (purity 99.999%), flow set is at 40sccm, regulate in cavity operating pressure to 1.0Pa, by Y metal targets (purity 99.9%) power regulation to 190W, pre-sputtering 10min; Then direct supply is connected to pure Si target (purity 99.99%), power regulation is to 190W, pre-sputtering 10min; To remove the contaminating impurities such as target material surface oxide compound, activation target material surface atom, carries the highly purified while and also improves the sputter rate of target.
3, d.c. sputtering deposition transition metal Y film
Confirm that cavity environment temperature is 130 ℃, magnesium alloy substrate temperature is 250 ℃.Regulate Ar flow to 60sccm, now chamber pressure is 1.50Pa, regulates chamber pressure to 0.30Pa; Rotate sample table, make sample table over against Y metal targets, both distances are 10cm; Target d.c. sputtering power is risen to 250W, open target plate washer, start timing, sputtering sedimentation 18s, closes rapidly target plate washer afterwards, regulates direct supply power to 0W.
4, RF-reactively sputtered titanium deposits outer amorphous Si
3n
4film
After transition metal Y film deposition, regulate Ar flow to 0sccm, keep 130 ℃ of cavity envrionment temperatures, magnesium alloy substrate temperature is 250 ℃, normally vacuumizes half an hour; Pass into afterwards high-purity N
2gas (purity 99.999%) and Ar gas, regulating nitrogen flow is 22%, total flux is 60sccm, regulates chamber pressure to 0.30Pa; Rotate sample table, make sample table over against pure Si target, both distances are 8cm; Access radio-frequency power supply, opens target plate washer, and target radio-frequency sputtering power is risen to 500W, starts timing, and sputtering sedimentation 95.5min, closes rapidly target plate washer afterwards, regulates direct supply power to 0W.
5, Y/Si
3n
4the total film thickness of composite coating material characterizes and adopts Dektak3 Series film thickness measuring instrument, and total film thickness is 3.01 μ m.The GIXRD spectrogram of embodiment 2 is with embodiment 1, and coating has the Y coating of close-packed hexagonal structure, does not occur the diffraction peak of silicon nitride, illustrates that silicon nitride is that non-crystalline state exists.The XPS figure of embodiment 2 depth profilings is with embodiment 1, and surface nitrogen SiClx is compound S i
3n
4.The section SEM figure similar embodiment 1 of embodiment 2, coating is fine and close, and the thickness of Y transition layer is 60 ± 5nm.The coating binding force test of embodiment 2 is with embodiment 1, and coating binding force is good.The Electrochemical results of embodiment 2 is with embodiment 1, with respect to plated film magnesium alloy not, and surface coverage Y/Si
3n
4the magnesium alloy of compound coating has good corrosion resistance.7 days liberations of hydrogen test of embodiment 2 is with embodiment 1, and result shows, at duration of test, and surface coverage Y/Si
3n
4the magnesium alloy of compound coating shows good corrosion resisting property (hydrogen-separating quantity levels off to zero).15 days salt-fog tests of embodiment 2 are with embodiment 1, and experimental standard is with reference to GBT6461-2002, and defect area is less than 0.5%, protection grading R
p>=8, consistent with test result before, surface coverage Y/Si is described
3n
4the magnesium alloy of compound coating has excellent corrosion resistance really.
Embodiment 3
1, substrate pretreatment
(1) mechanical mill polished finish is first ground to surfacing by magnesium alloy on 1000 order SiC silicon carbide papers, is placed in dehydrated alcohol ultrasonic cleaning 5min; Then on 2000 order SiC silicon carbide papers, be ground to cut in the same direction, be placed in ethanol ultrasonic cleaning 5min; Then on 5000 order SiC silicon carbide papers, along vertical 2000 order cut directions, grind 110s, be placed in ethanol ultrasonic cleaning 10min; With the diamond polishing cream that particle diameter is 1 μ m and 0.5 μ m, carry out polished finish on polishing disk successively again, polishing disk rotating speed is 600r/min, is polished to surface and is the nearly mirror status of light, distilled water flushing.
(2) ultrasonic cleaning is processed, with embodiment 1.
(3) ion source Bombardment and cleaning is processed, and adopts Hall ion source to clean matrix, and substrate temperature is 250 ℃, regulates Ar flow to 10sccm, and environmental stress is 2.3 * 10
-2pa, regulates bias voltage to be-100V, and cathodic current is 29A, and cathode voltage is 17V, and anodic current is 6.8A, and anode voltage is 57V, cleans 7min.
2, metal Y, pure Si target pre-sputtering
Cavity environment temperature is heated to 140 ℃, and magnesium alloy substrate temperature is heated to 250 ℃, passes into Ar gas (purity 99.999%), flow set is at 40sccm, regulate in cavity operating pressure to 1.0Pa, by Y metal targets (purity 99.9%) power regulation to 200W, pre-sputtering 10min; Then direct supply is connected to pure Si target (purity 99.99%), power regulation is to 200W, pre-sputtering 10min; To remove the contaminating impurities such as target material surface oxide compound, activation target material surface atom, carries the highly purified while and also improves the sputter rate of target.
3, d.c. sputtering deposition transition metal Y film
Confirm that cavity environment temperature is 140 ℃, magnesium alloy substrate temperature is 250 ℃.Regulate Ar flow to 60sccm, now chamber pressure is 1.50Pa, regulates chamber pressure to 0.30Pa; Rotate sample table, make sample table over against Y metal targets, both distances are 10cm; Target d.c. sputtering power is risen to 250W, open target plate washer, start timing, sputtering sedimentation 24s, closes rapidly target plate washer afterwards, regulates direct supply power to 0W.
4, RF-reactively sputtered titanium deposits outer amorphous Si
3n
4film
After transition metal Y film deposition, regulate Ar flow to 0sccm, keep 140 ℃ of cavity envrionment temperatures, magnesium alloy substrate temperature is 250 ℃, normally vacuumizes half an hour; Pass into afterwards high-purity N
2gas (purity 99.999%) and Ar gas, regulating nitrogen flow is 25%, total flux is 60sccm, regulates chamber pressure to 0.30Pa; Rotate sample table, make sample table over against pure Si target, both distances are 8cm; Access radio-frequency power supply, opens target plate washer, and target radio-frequency sputtering power is risen to 500W, starts timing, and sputtering sedimentation 95min, closes rapidly target plate washer afterwards, regulates direct supply power to 0W.
5, Y/Si
3n
4the total film thickness of composite coating material characterizes and adopts Dektak3 Series film thickness measuring instrument, and total film thickness is 2.97 μ m.The GIXRD spectrogram of embodiment 3 is with embodiment 1, and coating has the Y coating of close-packed hexagonal structure, does not occur the diffraction peak of silicon nitride, illustrates that silicon nitride is that non-crystalline state exists.The XPS figure of embodiment 3 depth profilings is with embodiment 1, and surface nitrogen SiClx is compound S i
3n
4.The section SEM figure similar embodiment 1 of embodiment 3, coating is fine and close, and the thickness of Y transition layer is 80 ± 5nm.The coating binding force test of embodiment 3 is with embodiment 1, and coating binding force is good.The Electrochemical results of embodiment 3 is with embodiment 1, with respect to plated film magnesium alloy not, and surface coverage Y/Si
3n
4the magnesium alloy of compound coating has good corrosion resistance.The liberation of hydrogen tests in 7 days of embodiment 3 are with embodiment 1, surface coverage Y/Si
3n
4the magnesium alloy of compound coating shows good corrosion resisting property (hydrogen-separating quantity convergence zero), and along with the prolongation of soak time, hydrogen-separating quantity increases to some extent, but still shows good corrosion resistance.7 days salt-fog tests of embodiment 3 are with embodiment 1, and experimental standard is with reference to GBT6461-2002, and defect area is less than 1%, protection grading R
p>=7, consistent with test result before, surface coverage Y/Si is described
3n
4the magnesium alloy of compound coating has good corrosion resistance really.
Embodiment 4
1, substrate pretreatment
(1) mechanical mill polished finish is first ground to surfacing by magnesium alloy on 1000 order SiC silicon carbide papers, is placed in dehydrated alcohol ultrasonic cleaning 5min; Then on 2000 order SiC silicon carbide papers, be ground to cut in the same direction, be placed in ethanol ultrasonic cleaning 5min; Then on 5000 order SiC silicon carbide papers, along vertical 2000 order cut directions, grind 120s, be placed in ethanol ultrasonic cleaning 10min; With the diamond polishing cream that particle diameter is 1 μ m and 0.5 μ m, carry out polished finish on polishing disk successively again, polishing disk rotating speed is 600r/min, is polished to surface and is the nearly mirror status of light, distilled water flushing.
(2) ultrasonic cleaning is processed, with embodiment 1.
(3) ion source Bombardment and cleaning is processed, and adopts Hall ion source to clean matrix, and substrate temperature is 250 ℃, regulates Ar flow to 10sccm, and environmental stress is 2.3 * 10
-2pa, regulates bias voltage to be-100V, and cathodic current is 29.2A, and cathode voltage is 17V, and anodic current is 7.2A, and anode voltage is 58V, cleans 6min.
2, metal Y, pure Si target pre-sputtering
Cavity environment temperature is heated to 150 ℃, and magnesium alloy substrate temperature is heated to 250 ℃, passes into Ar gas (purity 99.999%), flow set is at 40sccm, regulate in cavity operating pressure to 1.0Pa, by Y metal targets (purity 99.9%) power regulation to 200W, pre-sputtering 10min; Then direct supply is connected to pure Si target (purity 99.99%), power regulation is to 200W, pre-sputtering 10min; To remove the contaminating impurities such as target material surface oxide compound, activation target material surface atom, carries the highly purified while and also improves the sputter rate of target.
3, d.c. sputtering deposition transition metal Y film
Confirm that cavity environment temperature is 150 ℃, magnesium alloy substrate temperature is 250 ℃.Regulate Ar flow to 60sccm, now chamber pressure is 1.50Pa, regulates chamber pressure to 0.30Pa; Rotate sample table, make sample table over against Y metal targets, both distances are 10cm; Target d.c. sputtering power is risen to 250W, open target plate washer, start timing, sputtering sedimentation 30s, closes rapidly target plate washer afterwards, regulates direct supply power to 0W.
4, RF-reactively sputtered titanium deposits outer amorphous Si
3n
4film
After transition metal Y film deposition, regulate Ar flow to 0sccm, keep 150 ℃ of cavity envrionment temperatures, magnesium alloy substrate temperature is 250 ℃, normally vacuumizes half an hour; Pass into afterwards high-purity N
2gas (purity 99.999%) and Ar gas, regulating nitrogen flow is 25%, total flux is 60sccm, regulates chamber pressure to 0.30Pa; Rotate sample table, make sample table over against pure Si target, both distances are 8cm; Access radio-frequency power supply, opens target plate washer, and target radio-frequency sputtering power is risen to 500W, starts timing, and sputtering sedimentation 94min, closes rapidly target plate washer afterwards, regulates direct supply power to 0W.
5, Y/Si
3n
4the total film thickness of composite coating material characterizes and adopts Dektak3 Series film thickness measuring instrument, and total film thickness is 3.05 μ m.Y/Si in embodiment 4
3n
4with embodiment 1, there is Y diffraction peak in the GIXRD spectrogram of composite coating material, does not occur silicon nitride diffraction peak, and surface nitrogen SiClx exists with non-crystalline state.The XPS spectrum figure of embodiment 4 depth profilings is with embodiment 1, and result shows, silicon nitride is with compound S i
3n
4form exists.Fig. 9 is the section SEM figure of embodiment 4, (a) shows that Y is by Si
3n
4closely be connected with magnesium alloy substrate, coating is fine and close, and it is further amplified, and the thickness that can calculate Y transition layer from (b) is 100 ± 5nm.The coating binding force test of embodiment 4 is with embodiment 1, and coating binding force is good.Figure 10 and 11 is for the Electrochemical results of embodiment 4: Figure 10 is electrokinetic potential polarization curve, and Figure 11 is alternating-current impedance, and result shows, with respect to plated film magnesium alloy not, and surface coverage Y/Si
3n
4the magnesium alloy of compound coating has good corrosion resistance.Figure 12 is the liberation of hydrogen tests in 7 days of embodiment 4, and result shows, surface coverage Y/Si
3n
4the magnesium alloy of compound coating shows good corrosion resisting property (hydrogen-separating quantity is few), and along with the prolongation of soak time, hydrogen-separating quantity increases to some extent, but still shows good corrosion resistance.Figure 13 is 15 days salt-fog test cross-reference figure of embodiment 4, and experimental standard is with reference to GBT6461-2002, and defect area is less than 2.5%, protection grading R
p>=6, consistent with test result before, surface coverage Y/Si is described
3n
4the magnesium alloy of compound coating has good corrosion resistance.