CN109593985A - A kind of graphene enhancing magnesium-based composite material preparation method - Google Patents
A kind of graphene enhancing magnesium-based composite material preparation method Download PDFInfo
- Publication number
- CN109593985A CN109593985A CN201910031951.8A CN201910031951A CN109593985A CN 109593985 A CN109593985 A CN 109593985A CN 201910031951 A CN201910031951 A CN 201910031951A CN 109593985 A CN109593985 A CN 109593985A
- Authority
- CN
- China
- Prior art keywords
- magnesium
- composite material
- based composite
- graphene
- material preparation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/10—Alloys containing non-metals
- C22C1/1005—Pretreatment of the non-metallic additives
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D18/00—Pressure casting; Vacuum casting
- B22D18/06—Vacuum casting, i.e. making use of vacuum to fill the mould
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/10—Alloys containing non-metals
- C22C1/1036—Alloys containing non-metals starting from a melt
- C22C1/1047—Alloys containing non-metals starting from a melt by mixing and casting liquid metal matrix composites
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C23/00—Alloys based on magnesium
- C22C23/02—Alloys based on magnesium with aluminium as the next major constituent
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Composite Materials (AREA)
- Manufacture Of Alloys Or Alloy Compounds (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
The invention discloses a kind of graphenes to enhance magnesium-based composite material preparation method, this method is using redox graphene, lanthanum nitrate, nickel acetate and magnesium alloy as raw material, it is prepared especially by (1) compound, (2) control of vacuum melting and three steps of (3) suction pouring obtains graphene enhancing magnesium-based composite material.The method of the present invention significantly improves the defect of graphene Yu magnesium alloy compound tense, and the magnesium-based composite material made has excellent mechanical property, while preparation process is simple, and technique is controllable, and the cost of material is low, is suitable for industrialized production.
Description
Technical field
The invention belongs to field of composite material preparation, in particular to a kind of graphene enhancing magnesium-based composite material
Preparation method.
Background technique
It is constantly promoted along with graphene research boom, based on the excellent physical and chemical performance of graphene, people also attempt
Graphene is introduced into metal-base composites, it is expected that being carried out using performance of its a certain or certain characteristic to metallic matrix strong
Change, currently, many documents, which have been mentioned with graphene, strengthens the metallic matrixes such as Al, Cu, and graphene to the above metallic matrix all
Good invigoration effect can be played.
And in recent years, with the quick hair in the fields such as aerospace, automobile, electronics, lightweight structure material is proposed
Higher requirement, the graphene as most promising lightweight structure material enhances magnesium-based composite material, because having
The characteristics such as high specific strength and specific stiffness, excellent wear-resisting, damping, are widely paid close attention to and are paid attention to, therefore graphene is used
Also just become research emphasis to strengthen magnesium-based composite material.However, there are interface cohesion matter with magnesium matrix for research discovery graphene
The problem of amount difference and difficult dispersion, therefore how improving dispersibility and improving interface bond strength is to prepare High-performance graphene increasing
Strong magnesium-based composite material, which needs most, to be solved the problems, such as.
Summary of the invention
The purpose of the present invention is in view of the foregoing drawbacks, provide a kind of interface that can be improved graphene and magnesium-based composite material
Binding ability, while improving the magnesium-based enhancing composite material and preparation method thereof of the dispersibility of graphene.
In order to achieve the object of the present invention, by a large number of experiments research and unremitting effort, following technical solution is finally obtained:
A kind of preparation method of graphene enhancing magnesium-based composite material, includes the following steps:
(1) prepared by compound: redox graphene is put into the ethanol solution of lanthanum nitrate and nickel acetate, it is anti-through hydro-thermal
Intermediate product should be obtained, it is dry after product filtering, it is heat-treated under an ar atmosphere later, obtains compound；
(2) vacuum melting: furnace temperature is first increased to 150-200 DEG C and is preheated, then magnesium alloy is added in crucible, together
When be passed through inert gas, make air pressure >=1 × 10 in furnace4Pa increases temperature to 680-750 DEG C, after magnesium alloy is completely melt, removes
After standing 10-15min, after change temperature is 580-620 DEG C, the compound of quality of magnesium alloy 3-10% is added in surface slag, it
Mechanical stirring dispersion is carried out afterwards, obtains evenly dispersed Composite Melt；
(3) suction pouring: the Composite Melt that step 2 is obtained stands 5-10min, surface slag is removed, using true
Suction casting obtains graphene enhancing magnesium-based composite material.
Preferably, magnesium-based as described above enhances composite material and preparation method thereof, in step (1) by graphene investment lanthanum nitrate with
In the ethanol solution of nickel acetate, the temperature constant magnetic stirring at 50-75 DEG C, adjusting pH value of solution is 6-7, has put it into polytetrafluoroethyl-ne
In the reaction kettle of alkene liner, hydro-thermal reaction is carried out, intermediate product is obtained.
Preferably, magnesium-based as described above enhances composite material and preparation method thereof, when adjusting ethanol solution pH, into ethanol solution
The ammonium hydroxide that concentration is 25% is added dropwise with 1-2 drop/s speed.
Preferably, magnesium-based as described above enhances composite material and preparation method thereof, and hydrothermal temperature is 110-130 DEG C, heat preservation
Time 4-8h.
Preferably, magnesium-based as described above enhances composite material and preparation method thereof, carries out heat treatment tool under Ar atmosphere in step (1)
Body parameter is that 450-600 DEG C is warming up to the rate of 4-10 DEG C/min, keeps the temperature 1.5-2h.
Preferably, magnesium-based as described above enhances composite material and preparation method thereof, and step (1) redox graphene and ethyl alcohol are molten
The ratio of liquid is 1g:(80-120) ml, and the molar ratio of lanthanum nitrate and lanthanum element in nickel acetate and nickel element is in ethanol solution
(0.05-0.12): 1, the molar concentration of lanthanum nitrate is 0.05-0.1mol/L.
Preferably, magnesium-based as described above enhances composite material and preparation method thereof, and mechanical stirring rate is 150- in step (2)
300 turns/min, mixing time 5-20min.
Preferably, magnesium-based as described above enhances composite material and preparation method thereof, and inert gas is argon gas or helium in step (2)
Gas.
Preferably, magnesium-based as described above enhances composite material and preparation method thereof, and magnesium alloy is AZ91D magnesium alloy in step (2).
Preferably, magnesium-based as described above enhances composite material and preparation method thereof, suction pouring condition in step (3) are as follows: vacuum
Pressure is less than 0.1 × 10-3Pa, dwell time 5-10min.
Redox graphene is to prepare oxygen using improved Hummers method using crystalline flake graphite as raw material in the present invention
Graphite alkene (GO), then redox graphene (RGO) is prepared by ultrasound/ultraviolet light reducing process, naturally it is also possible to it is
Other redox graphene materials that can be obtained according to existing method.
The present invention compared with the existing technology, has the following technical effect that
(1) graphene that the method for the present invention obtains enhances magnesium-based composite material excellent in mechanical performance, tensile strength 292-
At least 16.8%, 75.7% and has been respectively increased in 337MPa, elongation percentage 12.3-17.4%, surface hardness 94-112HV
13.2%；
(2) the present invention provides a kind of new method for enhancing magnesium alloy using graphene, this method is significantly improved
Defect existing for graphene and magnesium alloy compound tense, has wide practical use；
(3) the method for the present invention preparation process is simple, and technique is controllable, and the cost of material is low, is suitable for industrialized production.
Specific embodiment
Technical solution of the present invention is clearly and completely described below with reference to embodiment, the following example is only used for
Illustrate the present invention, and is not construed as limiting the scope of protection of the present invention.In addition, particular technique operating procedure is not specified in embodiment
Or condition person, described technology or conditions or carried out according to the literature in the art according to product description.Examination used
Production firm person is not specified in agent or instrument, and being can be with conventional products that are commercially available.
Embodiment 1
Graphene enhances magnesium-based composite material preparation:
Step 1: 20g redox graphene is put into the ethanol solution of 2000ml lanthanum nitrate and nickel acetate, wherein
The molar concentration of lanthanum nitrate is 0.05mol/L, and the molar ratio of lanthanum element and nickel element is 0.05:1 in lanthanum nitrate and nickel acetate,
Temperature constant magnetic stirring 1h at 55 DEG C, with 1-2 drop/s speed be added dropwise concentration be 25% ammonium hydroxide, adjust pH value of solution be 6, then by its
It is put into the reaction kettle of polytetrafluoroethyllining lining, carries out hydro-thermal reaction, hydrothermal temperature is 110 DEG C, and soaking time 8h is obtained
It is dry after product filtering to intermediate product, it is heat-treated under an ar atmosphere later, heat treatment design parameter is with 5 DEG C/min
Rate be warming up to 500 DEG C, keep the temperature 2h, obtain compound；
Step 2: furnace temperature being first increased to 150 DEG C and is preheated, then AZ91D magnesium alloy is added in crucible, is led to simultaneously
Enter helium, makes air pressure >=1 × 10 in furnace4Pa increases temperature to 700 DEG C, after AZ91D magnesium alloy is completely melt, removes surface
After standing 10min, after change furnace temperature is 580 DEG C, the compound of AZ91D quality of magnesium alloy 4% is added, later with 150 in slag
Turn/min progress mechanical stirring, mixing time 20min obtains evenly dispersed Composite Melt；
Step 3: the Composite Melt that step 2 is obtained stands 5min, removes surface slag, is obtained using vacuum suction casting technique
Enhance magnesium-based composite material to graphene, wherein suction pouring condition are as follows: vacuum pressure is less than 0.1 × 10-3Pa, dwell time 5-
10min。
Embodiment 2
Graphene enhances magnesium-based composite material preparation:
Step 1: 10g redox graphene being put into the ethanol solution of 800ml lanthanum nitrate and nickel acetate, wherein nitric acid
The molar concentration of lanthanum is 0.08mol/L, and the molar ratio of lanthanum element and nickel element is 0.08:1 in lanthanum nitrate and nickel acetate, at 75 DEG C
The ammonium hydroxide that concentration is 25% is added dropwise with 1-2 drop/s speed in lower temperature constant magnetic stirring 1h, and adjusting pH value of solution is 7, has put it into
In the reaction kettle of polytetrafluoroethyllining lining, hydro-thermal reaction is carried out, hydrothermal temperature is 130 DEG C, and soaking time 4h obtains centre
Product, it is dry after product filtering, it is heat-treated under an ar atmosphere later, heat treatment design parameter is with the rate of 10 DEG C/min
600 DEG C are warming up to, 1.5h is kept the temperature, obtains compound；
Step 2: furnace temperature being first increased to 200 DEG C of preheated one-section times, then AZ91D magnesium alloy is added in crucible, together
When be passed through helium, make air pressure >=1 × 10 in furnace4Pa increases temperature to 750 DEG C, after AZ91D magnesium alloy is completely melt, removes
Surface slag, stand 15min after, change temperature be 600 DEG C after, be added AZ91D quality of magnesium alloy 8% compound, it is laggard
The dispersion of row mechanical stirring, mechanical stirring rate are 250 turns/min, mixing time 10min, and it is molten to obtain evenly dispersed composite material
Body；
Step 3: the Composite Melt that step 2 is obtained stands 10min, surface slag is removed, using vacuum suction casting technique
Graphene enhancing magnesium-based composite material is obtained, wherein suction pouring condition are as follows: vacuum pressure is less than 0.1 × 10-3Pa, dwell time
5-10min。
Embodiment 3
Graphene enhances magnesium-based composite material preparation:
Step 1: 10g redox graphene being put into the ethanol solution of 1200ml lanthanum nitrate and nickel acetate, wherein nitre
The molar concentration of sour lanthanum is 0.1mol/L, and the molar ratio of lanthanum element and nickel element is 0.12:1 in lanthanum nitrate and nickel acetate, 60
The ammonium hydroxide that concentration is 25% is added dropwise with 1-2 drop/s speed in temperature constant magnetic stirring 1h at DEG C, and adjusting pH value of solution is 6.5, is put
Enter to have in the reaction kettle of polytetrafluoroethyllining lining, carry out hydro-thermal reaction, hydrothermal temperature is 120 DEG C, and soaking time 6h is obtained
Intermediate product, it is dry after product filtering, it is heat-treated under an ar atmosphere later, heat treatment design parameter is with 7 DEG C/min's
Rate is warming up to 450 DEG C, keeps the temperature 2h, obtains compound；
Step 2: furnace temperature being first increased to 180 DEG C of preheated one-section times, then AZ91D magnesium alloy is added in crucible, together
When be passed through helium, make air pressure >=1 × 10 in furnace4Pa increases temperature to 680 DEG C, after AZ91D magnesium alloy is completely melt, removes
Surface slag, stand 10min after, change temperature be 620 DEG C after, be added AZ91D quality of magnesium alloy 10% compound, it is laggard
The dispersion of row mechanical stirring, mechanical stirring rate are 300 turns/min, mixing time 5min, and it is molten to obtain evenly dispersed composite material
Body；
Step 3: the Composite Melt that step 2 is obtained stands 8min, removes surface slag, is obtained using vacuum suction casting technique
Enhance magnesium-based composite material to graphene, wherein suction pouring condition are as follows: vacuum pressure is less than 0.1 × 10-3Pa, dwell time 5-
10min。
Embodiment 4
Magnesium-based composite material is enhanced according to metal material room-temperature mechanical property phase to the graphene that embodiment 1-3 is prepared
It closes detection method to be detected, as a result as shown in the table.
| Project | Embodiment 1 | Embodiment 2 | Embodiment 3 | AZ91D |
| Tensile strength (MPa) | 292 | 314 | 337 | 250 |
| Elongation percentage (%) | 12.3 | 15.8 | 17.4 | 7% |
| Surface hardness (HV) | 94 | 104 | 112 | 83 |
Comparative example 1
On the basis of embodiment 3, changing the step the compound being added in 3 is quality of magnesium alloy 12%, is answered what is obtained
Condensation material carries out detection and finds that its tensile strength is 301MPa, elongation percentage 13.2%, surface hardness 97HV.
Comparative example 2
On the basis of embodiment 1, the ethanol solution of lanthanum nitrate and nickel acetate is molten with the ethyl alcohol of same concentrations nickel acetate
Liquid replacement carries out detection to obtained composite material and finds that its tensile strength is 282MPa, elongation percentage 10.3%, surface hardness
89HV。
Comparative example 3
On the basis of embodiment 1, the ethanol solution of lanthanum nitrate and nickel acetate is molten with the ethyl alcohol of same concentrations lanthanum nitrate
Liquid replacement carries out detection to obtained composite material and finds that its tensile strength is 267MPa, elongation percentage 9.4%, surface hardness
87HV。
Comparative example 4
On the basis of embodiment 1, the ethanol solution of lanthanum nitrate and the ethanol solution cobalt nitrate of nickel acetate is replaced,
The concentration of middle cobalt nitrate is 1mol/L, carries out detection to obtained composite material and finds that its tensile strength is 274MPa, elongation percentage
11.4%, surface hardness 91HV.
Comparative example 5
On the basis of embodiment 2, without Overheating Treatment, directly progress step 2 place after product filtration drying in step 1
Reason carries out detection to obtained composite material and finds that its tensile strength is 294MPa, elongation percentage 12.8%, surface hardness 95HV.
Claims (10)
1. a kind of graphene enhances magnesium-based composite material preparation method, it is characterised in that include the following steps:
(1) prepared by compound: redox graphene being put into the ethanol solution of lanthanum nitrate and nickel acetate, is obtained through hydro-thermal reaction
It is dry after product filtering to intermediate product, it is heat-treated under an ar atmosphere later, obtains compound；
(2) vacuum melting: being first increased to 150-200 DEG C for furnace temperature and preheat, then magnesium alloy is added in crucible, leads to simultaneously
Enter inert gas, makes air pressure >=1 × 10 in furnace4Pa increases temperature to 680-750 DEG C, after magnesium alloy is completely melt, removes surface
Slag, stand 10-15min after, change temperature be 580-620 DEG C after, be added quality of magnesium alloy 3-10% compound, it is laggard
The dispersion of row mechanical stirring, obtains evenly dispersed Composite Melt；
(3) suction pouring: the Composite Melt that step 2 is obtained stands 5-10min, removes surface slag, is inhaled using vacuum
Casting obtains magnesium-based composite material.
2. graphene enhances magnesium-based composite material preparation method according to claim 1, it is characterised in that: will in step (1)
Graphene is put into the ethanol solution of lanthanum nitrate and nickel acetate, the temperature constant magnetic stirring at 50-75 DEG C, and adjusting pH value of solution is 6-7,
It puts it into the reaction kettle of polytetrafluoroethyllining lining, carries out hydro-thermal reaction, obtain intermediate product.
3. graphene enhances magnesium-based composite material preparation method according to claim 2, it is characterised in that: adjust ethanol solution
When pH, the ammonium hydroxide that concentration is 25% is added dropwise with 1-2 drop/s speed into ethanol solution.
4. graphene enhances magnesium-based composite material preparation method according to claim 2, it is characterised in that: hydrothermal temperature
It is 110-130 DEG C, soaking time 4-8h.
5. graphene enhances magnesium-based composite material preparation method according to claim 1, it is characterised in that: Ar in step (1)
It is that 450-600 DEG C is warming up to the rate of 4-10 DEG C/min that heat treatment design parameter is carried out under atmosphere, keeps the temperature 1.5-2h.
6. graphene enhances magnesium-based composite material preparation method according to claim 1, it is characterised in that: step (1) reduction
The ratio of graphene oxide and ethanol solution is 1g:(80-120) ml, in ethanol solution in lanthanum nitrate and nickel acetate lanthanum element with
The molar ratio of nickel element is (0.05-0.12): 1, the molar concentration of lanthanum nitrate is 0.05-0.1mol/L.
7. graphene enhances magnesium-based composite material preparation method according to claim 1, it is characterised in that: machine in step (2)
Tool stirring rate is that 150-300 turns/min, mixing time 5-20min.
8. graphene enhances magnesium-based composite material preparation method according to claim 1, it is characterised in that: lazy in step (2)
Property gas be argon gas or helium.
9. graphene enhances magnesium-based composite material preparation method according to claim 1, it is characterised in that: magnesium in step (2)
Alloy is AZ91D magnesium alloy.
10. graphene enhances magnesium-based composite material preparation method according to claim 1, it is characterised in that: true in step (3)
Suction cast bar part are as follows: vacuum pressure is less than 0.1 × 10-3Pa, dwell time 5-10min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910031951.8A CN109593985A (en) | 2019-01-14 | 2019-01-14 | A kind of graphene enhancing magnesium-based composite material preparation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910031951.8A CN109593985A (en) | 2019-01-14 | 2019-01-14 | A kind of graphene enhancing magnesium-based composite material preparation method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109593985A true CN109593985A (en) | 2019-04-09 |
Family
ID=65965038
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910031951.8A Withdrawn CN109593985A (en) | 2019-01-14 | 2019-01-14 | A kind of graphene enhancing magnesium-based composite material preparation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109593985A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111549246A (en) * | 2020-04-24 | 2020-08-18 | 郑州大学 | Preparation method of high-toughness graphene/ZK 61 magnesium alloy composite material |
| CN114023959A (en) * | 2021-11-09 | 2022-02-08 | 西安亚弘泰新能源科技有限公司 | Preparation method of magnesium-containing novel graphene lithium ion battery cathode material |
-
2019
- 2019-01-14 CN CN201910031951.8A patent/CN109593985A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111549246A (en) * | 2020-04-24 | 2020-08-18 | 郑州大学 | Preparation method of high-toughness graphene/ZK 61 magnesium alloy composite material |
| CN114023959A (en) * | 2021-11-09 | 2022-02-08 | 西安亚弘泰新能源科技有限公司 | Preparation method of magnesium-containing novel graphene lithium ion battery cathode material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11634333B2 (en) | Boron-containing titanium-based composite powder for 3D printing and method of preparing same | |
| CN100575517C (en) | A kind of preparation method of granule intensified titanium-base compound material | |
| CN111515381A (en) | High-strength and high-toughness titanium alloy powder for laser additive manufacturing and preparation method thereof | |
| CN109593985A (en) | A kind of graphene enhancing magnesium-based composite material preparation method | |
| US20200246875A1 (en) | Method for preparing vanadium and vanadium alloy powder from vanadium-containing materials through shortened process | |
| CN110846547A (en) | High-entropy alloy combined tungsten carbide hard alloy and preparation method thereof | |
| CN105177390A (en) | Metal ceramics and preparation method thereof | |
| CN113427008B (en) | Tantalum-tungsten alloy powder and preparation method thereof | |
| CN101921930A (en) | Multicomponent microalloyed titanium alloy and preparation method thereof | |
| CN111235452A (en) | Ti (C, N) -based hard alloy material and preparation method thereof | |
| CN103276323A (en) | Preparation method of high-strength and corrosion-resistant composite heat exchanger tube | |
| CN108746656B (en) | Pre-alloyed powder for diamond products and preparation method thereof | |
| CN108585870A (en) | A kind of La2O3-Al2O3-(W,Mo2) C non-bond cemented carbide materials and preparation method thereof | |
| CN109865833B (en) | Powder metallurgy preparation method of titanium or titanium alloy product, and titanium or titanium alloy product | |
| CN103131859B (en) | Comprehensive recycling method for metals in superalloy scrap | |
| CN108998699A (en) | A kind of aluminium lithium based composites powder and its preparation method and application | |
| WO2012065455A1 (en) | Aluminum-zirconium-titanium-carbon crystal grain refiner for magnesium and magnesium alloys and preparation method thereof | |
| CN113249630A (en) | Forging and pressing process of high-entropy alloy | |
| CN109234602B (en) | Chromium vanadium carbonitride alloy and preparation method thereof | |
| CN109694969B (en) | Pre-alloyed powder, TiCN-based metal ceramic composite material added with pre-alloyed powder and preparation method of TiCN-based metal ceramic composite material | |
| CN104651643A (en) | Preparation method of dual-scale SiC particle reinforced aluminium-based composite material | |
| CN109468569B (en) | Wear-resistant corrosion-resistant alloy coating and method for preparing coating | |
| CN112209446A (en) | Method for recycling Cr-containing tungsten carbide waste and application thereof | |
| CN110629060B (en) | Grain refiner containing rare earth elements and preparation method and application thereof | |
| CN108274005B (en) | A method of low cobalt, ultra-fine cemented carbide bar are prepared with nanometer WC-Co composite powder |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20190409 |