CN106544537A - A kind of preparation method of carbon nanotube enhanced aluminium-based composite material - Google Patents
A kind of preparation method of carbon nanotube enhanced aluminium-based composite material Download PDFInfo
- Publication number
- CN106544537A CN106544537A CN201610928860.0A CN201610928860A CN106544537A CN 106544537 A CN106544537 A CN 106544537A CN 201610928860 A CN201610928860 A CN 201610928860A CN 106544537 A CN106544537 A CN 106544537A
- Authority
- CN
- China
- Prior art keywords
- ball
- powder
- composite
- carbon nanotube
- 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.)
- Granted
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
- C22C1/04—Making non-ferrous alloys by powder metallurgy
- C22C1/05—Mixtures of metal powder with non-metallic powder
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C21/00—Alloys based on aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C26/00—Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C26/00—Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
- C22C2026/002—Carbon nanotubes
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacture Of Alloys Or Alloy Compounds (AREA)
Abstract
The invention provides a kind of preparation method of carbon nanotube enhanced aluminium-based composite material, the method obtains the homodisperse composite powder of carbon pipe initially with low temperature ball milling, then powder consolidation is obtained into composite blank through dress jacket, degasification and high temperature insostatic pressing (HIP), the conventional hot-working method such as Jing extruding, forging and stamping forms bar, section bar or forging products again, finally carries out heat treatment.The method CNT can be made to obtain in alloy matrix aluminum good dispersibility, its reinforcement degree of injury are little, the composite microstructure of formation is uniform, interface cohesion is good.The material simultaneously has high intensity and plasticity, is expected to be applied to Aero-Space, automobile etc. have the field of tight demand to high-strength light structural material.
Description
Technical field
The invention provides a kind of preparation method of carbon nanotube enhanced aluminium-based composite material, belongs to metal-base composites
Technical field.
Background technology
Aluminum matrix composite has high specific strength, specific modulus, good conductive and heat-conductive and high-temperature behavior, in aviation
Applied and caused increasing concern in the fields such as space flight, automobile and microelectronics.CNT have unique structure and
Excellent physics, chemical property (its Young's modulus up to 1-1.8TPa, tensile strength up to 150GPa, density up to 1.2～
1.8g/cm3, thermal coefficient of expansion is almost nil, while also having good toughness and plastic deformation ability), its combination property is remote
Better than the granule or fiber that presently, there are, it is a kind of preferable reinforcement of composite.However, carbon pipe specific surface area is big, surface
Can be high, being often attached together with Van der Waals force between them, (Van der Waals between the CNT for contacting with each other combine energy
About 500eV/ μm) form aggregate；Additionally, carbon pipe surface inertia is big, lack active group, the dissolubility in various solvents
It is all very low, this just to its dispersion in the base and they bring very big difficulty with intermetallic interface cohesion.
In order that carbon pipe is uniformly distributed and obtains high performance aluminum matrix composite in the base, various countries' researcher is in mistake
Organic solvent and ultrasonic disperse, high-energy ball milling, fabricated in situ, molecular scale mixing, melt infiltration are employed in the more than ten years gone
Etc. method, these technologies of preparing are all achieved successfully to a certain extent.The but performance of CNTs/Al composites and theoretical phase
Than, still there are greatest differences, its potentiality is brought into play far away.The CNT for being presently used for aluminum matrix composite preparation is big
More using CVD preparation, compare with graphite acr method with laser evaporization method, the method has that yield is big, the low advantage of cost, but by
The carbon pipe of this production often mutually crimps, is intertwined, and this obviously brings bigger obstacle to dispersive process.By carbon nanometer
Pipe in the base it is dispersed can be related to mostly carbon length of tube shorten (either will add matrix after carbon pipe shortization in advance,
Or prescind during mixing with matrix), high-energy ball milling so which is simple to operate, can batch processing become at present extensively
One of method for using.Obviously, shortization can cause carbon pipe end-blown to increase, and structural intergrity is reduced, additionally, in mechanical milling process
Strong collision also can to structural pipe wall cause damage.Theoretically, CNT be considered as by graphite-based roll it is bent and
Into its reactivity is very low, and (surface free energy is only 0.15J/m2), but due to the generation of various defects, itself and alloy matrix aluminum
Chemical reaction will occur at high temperature and generate carbide (Al4C3).Carbon be difficult to spontaneous profit including the most metals including Al
It is wet, although research shows that interfacial reaction to a certain extent can improve wettability, increase interface bond strength, but in a large number
The generation of reactant undoubtedly weakens the degree of injury of reinforcement in the invigoration effect of reinforcement, therefore reduction composite, essence
Really regulation and control interface structure is equally a very important problem.
The content of the invention
The problem that the present invention is present for above-mentioned prior art, there is provided a kind of carbon nanotube enhanced aluminium-based composite material
Preparation method, its objective is to realize dispersed, reduction reinforcement degree of injury of the CNT in alloy matrix aluminum, is formed
Microstructure is uniform, the high-performance aluminum-base composite material that interface cohesion is good.
The purpose of the present invention is achieved through the following technical solutions：
The preparation process of this kind of carbon nanotube enhanced aluminium-based composite material is：The aluminum that mean diameter is 10～120 μm is closed
Bronze end is loaded in stirring ball mill with CNT, and being passed through liquid nitrogen (or liquid argon) carries out low temperature ball milling.In mechanical milling process, carbon
Nanotube, metal dust and abrading-ball are fully immersed in liquid nitrogen；After ball milling terminates, powder slurries are collected in rustless steel container
And stand.After liquid nitrogen volatilization, dry powder is loaded into aluminum jacket, deaerated, high temperature insostatic pressing (HIP) makes aluminum matrix composite base
Blank is carried out hot extrusion, hot rolling or forging and makes bar, section bar, sheet material or forging, finally carries out heat treatment by material.Wherein：
A diameter of 10～80nm of the CNT, length are 2～50 μm, account for the 0.1～5% of composite powder quality；
The technological parameter of ball milling is：Rotational speed of ball-mill be 80～500r/min, Ball-milling Time be 0.5～10h, ball material mass ratio
For 1:5～50, Material quality of grinding balls is steel or ceramics, a diameter of 3～15mm；
The technological parameter of degasification is：Using resistance furnace and vacuum pump set the aluminum jacket for loading composite powder is carried out heating and
Evacuation, is first evacuated to vacuum at room temperature less than 1 × 10-1Pa, then begins to warm up, and keeps evacuation, when temperature is reached
When 300 DEG C, 2～5h is incubated, it is finally heated to 440～500 DEG C, and vacuum is evacuated to less than 2 × 10-3Pa, then will be except QI KOU
Soldering and sealing；
The technological parameter of high temperature insostatic pressing (HIP) is：To the hip temperature that the mixed-powder in jacket carries out consolidating molding it is
400～500 DEG C, pressure is 100～130MPa, and the time is 2～5h.
Aluminum jacket is obtained by pure aluminum or aluminum alloy, with except QI KOU.Aluminum matrix composite blank is removed by machining car
Obtain after aluminium alloy jacket.
Technical solution of the present invention has compared with existing high-energy ball milling method prepares carbon nanotube enhanced aluminium-based composite material
Advantages below：
(1) Ball-milling Time is short, and the dispersion of carbon pipe is more uniform
The present invention carries out ball milling in liquid nitrogen, and under low temperature, the flexible reduction of carbon pipe, is more easy to generation disconnected under shear action
Split, so as to quick shortization of carbon pipe, winding body is disengaged；On the other hand, strong mechanical agitation and liquid-nitrogen boiling make carbon pipe and
Al alloy powder mixes repeatedly, therefore reinforcement being uniformly distributed in the base is able to quickly realize (about several hours), and passes
System ball milling is typically in 15-48h.Additionally, under low temperature, metal dust cold welding weakens, it is easy to develops towards flaking direction, increases
With the contact area of CNT, also so that dispersibility is further improved.
(2) powder high purity, process contamination are little
Ball milling in the present invention is carried out in inertia cryogenic media, substantially not with air contact, therefore Powder Oxidation can
Can property very little.Compared with traditional ball milling, it is not required that addition suppresses the process control agent (such as stearic acid etc.) of coldwelding, further
Reduce the pollution of external additive.
(3) in composite, carbon tubular construction is complete, is well combined with basal body interface
As the process time of low temperature ball milling is short, while belonging to wet ball grinding, mixed process is relatively soft, so as to reduce
The wall defects that collision causes.When carrying out being consolidated into type using high temperature insostatic pressing (HIP) and extruding, no large-sized brittle carbides
Produce, carbon pipe is maintained as the invigoration effect of reinforcement；But meanwhile, the nanoscale generated at former carbon defective tube
Al4C3Wettability is improve, interface bond strength is increased.
Description of the drawings
Fig. 1 is the schematic diagram of stirring ball mill in embodiment
The transmission electron microscope photo of Fig. 2 (a) and (b) for composite in embodiment
Fig. 3 is the Raman scattering collection of illustrative plates of composite in embodiment
Specific embodiment
Technical solution of the present invention is described in further detail below in conjunction with drawings and Examples：
Embodiment
Using 2009 Al alloy powders, its composition is 3.0wt.%Cu, 1.5wt.%Mg, Al surplus, and mean diameter is 30 μ
m；The nominal diameter of multi-walled carbon nano-tubes is 40～60nm, and length is 5～15 μm.The Al alloy powder of 1kg and many wall carbon are received
The mixed-powder of mitron and 40Kg abrading-balls load in stirring ball mill, and Material quality of grinding balls is ZrO2, multi-walled carbon nano-tubes accounts for mixing
The 1.0% of powder quality, ball radius are respectively 3mm, 5mm, 8mm, and corresponding mass ratio is 2:1:1, accompanying drawing 1 is stirring-type ball
Grinding machine schematic diagram.
Liquid nitrogen is passed through in ball grinder, after abrading-ball and mixed-powder are totally immersed in liquid nitrogen, starts ball milling, its rotating speed is
180r/min, Ball-milling Time are 2h.Observation amount of liquid nitrogen is noted in mechanical milling process so as to abrading-ball and mixed powder can be flooded all the time
End, otherwise, first suspends ball milling and supplements liquid nitrogen.After ball milling terminates, powder slurries are collected in rustless steel container, stand 3h,
After liquid nitrogen volatilization, dry composite powder is obtained.
Dry composite powder is loaded in the aluminum jacket of 80 × 180mm of Ф, jacket vacuum is evacuated at room temperature little
In 1 × 10-1Pa, then begins to warm up, and keeps evacuation, when temperature reaches 300 DEG C, is incubated 2h, is then heated to 480
DEG C, degasification to vacuum is less than 2 × 10-3Pa, finally sealed.
Jacket is carried out into high temperature insostatic pressing (HIP), temperature is 465 DEG C, and pressure is 120MPa, time 3h.
Aluminum jacket is removed by machining, carbon nanotube enhanced aluminium-based composite material blank is obtained.Extrude in 1000t bedrooms
Blank is hot extruded into into bar on machine, extrusion temperature is 460 DEG C, and extruding rate 2mm/s, extrusion ratio are 18：1, extruded barses are straight
Footpath is Ф 15mm.
By extruded barses at 498 DEG C solution treatment 4h, then quench in room temperature water, finally carry out natrual ageing.
Table 1 gives the room temperature tensile properties of the high-performance carbon nanotube reinforced aluminum matrix composites of present invention preparation, with
Aluminum matrix alloy is compared, and tension and yield strength are significantly improved (be respectively increased 25% and 24%), and still has good plasticity
(elongation percentage is 10.2%), compared with having been reported, (Liu etc., 2012), in the present invention, either tensile strength, yield strength be also
It is that elongation percentage is all significantly higher than the latter.Microstructure photos of the Fig. 2 for composite, it is seen that its crystal grain is tiny, while tubulose knot
The CNT of structure is uniformly distributed in the base.Fig. 3 gives the Raman spectrum of composite and original state CNT, with reference to
Microscopic appearance, further demonstrate that the structure of carbon pipe in material preparation process keeps preferable, and ID/IGValue increase mainly due to
The change of carbon length of tube causes.
The mechanical property of 1 CNT/2009 aluminum matrix composites of table
[1]Z.Y.Liu,B.L.Xiao,W.G.Wang,et al.Carbon 50(5)(2012)1843-1852.
Claims (2)
1. a kind of preparation method of carbon nanotube enhanced aluminium-based composite material, it is characterised in that：It it is 10～120 μm by mean diameter
Al alloy powder and CNT load in stirring ball mill, being passed through liquid nitrogen or liquid argon carries out low temperature ball milling, after ball milling
Powder slurries load aluminum jacket after drying, and deaerated, high temperature insostatic pressing (HIP) makes aluminum matrix composite blank, and blank is carried out hot extrusion
Bar, section bar, sheet material or forging are made in pressure, hot rolling or forging, finally carry out heat treatment, in：
A diameter of 10～80nm of the CNT, length are 2～50 μm, account for the 0.1～5% of composite powder quality；
The technological parameter of ball milling is：Rotational speed of ball-mill is 80～500r/min, and Ball-milling Time is 0.5～10h, and ball material mass ratio is 1:
5～50, Material quality of grinding balls is steel or ceramics, a diameter of 3～15mm；
The technological parameter of degasification is：The aluminum jacket for loading composite powder is heated using resistance furnace and vacuum pump set and taken out and be true
Sky, is first evacuated to vacuum at room temperature less than 1 × 10-1Pa, then begins to warm up, and keeps evacuation, when temperature reaches 300 DEG C
When, 2～5h is incubated, it is finally heated to 440～500 DEG C, and vacuum is evacuated to less than 2 × 10-3Pa；
The technological parameter of high temperature insostatic pressing (HIP) is：To the mixed-powder in jacket carry out consolidate molding hip temperature be 400～
500 DEG C, pressure is 100～130MPa, and the time is 2～5h.
2. the preparation method of carbon nanotube enhanced aluminium-based composite material according to claim 1, it is characterised in that：Carbon nanometer
Pipe is used after pretreatment, and pretreatment is surface functionalization, graphitization or nickel plating, copper.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610928860.0A CN106544537B (en) | 2016-10-31 | 2016-10-31 | A kind of preparation method of carbon nanotube enhanced aluminium-based composite material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610928860.0A CN106544537B (en) | 2016-10-31 | 2016-10-31 | A kind of preparation method of carbon nanotube enhanced aluminium-based composite material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106544537A true CN106544537A (en) | 2017-03-29 |
| CN106544537B CN106544537B (en) | 2018-04-03 |
Family
ID=58392516
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610928860.0A Active CN106544537B (en) | 2016-10-31 | 2016-10-31 | A kind of preparation method of carbon nanotube enhanced aluminium-based composite material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106544537B (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107099687A (en) * | 2017-04-14 | 2017-08-29 | 武汉理工大学 | A kind of boron carbide particles strengthen the preparation method of nanometer/Ultra-fine Grained aluminum matrix composite |
| CN112024896A (en) * | 2020-10-16 | 2020-12-04 | 湘潭大学 | Preparation method of CNTs-ZA27 zinc-aluminum-based composite bar with high C content |
| CN112111700A (en) * | 2020-09-02 | 2020-12-22 | 上海交通大学 | Online quenching heat treatment method for nano-carbon reinforced aluminum alloy composite extruded section |
| CN113373341A (en) * | 2021-06-18 | 2021-09-10 | 苏州第一元素纳米技术有限公司 | Manufacturing process of carbon nano tube reinforced aluminum electric power fitting |
| CN113684391A (en) * | 2021-08-20 | 2021-11-23 | 中国兵器科学研究院宁波分院 | Preparation method of high-performance aluminum alloy and composite material thereof |
| CN114950649A (en) * | 2022-04-29 | 2022-08-30 | 中国人民解放军总医院第三医学中心 | Constant-low-temperature grinding device and method for preparing micron-sized biological hard tissue material |
| CN115261689A (en) * | 2022-07-29 | 2022-11-01 | 苏州第一元素纳米技术有限公司 | Light aluminum alloy composite material and preparation method and application thereof |
| CN116497250A (en) * | 2023-06-27 | 2023-07-28 | 有研工程技术研究院有限公司 | High-modulus aluminum-based composite foil and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102676860A (en) * | 2012-05-23 | 2012-09-19 | 天津大学 | Preparation method of carbon nanotube reinforced Al-matrix composite |
-
2016
- 2016-10-31 CN CN201610928860.0A patent/CN106544537B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102676860A (en) * | 2012-05-23 | 2012-09-19 | 天津大学 | Preparation method of carbon nanotube reinforced Al-matrix composite |
Non-Patent Citations (3)
| Title |
|---|
| 何天兵等: "碳纳米管增强金属基复合材料的研究进展", 《材料工程》 * |
| 张坤等: "低温球磨制备纳米晶铝/铝基复合材料的研究进展和应用前景", 《材料导报A》 * |
| 王洪磊等: "碳纳米管增强复合材料的研究进展", 《材料导报》 * |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107099687A (en) * | 2017-04-14 | 2017-08-29 | 武汉理工大学 | A kind of boron carbide particles strengthen the preparation method of nanometer/Ultra-fine Grained aluminum matrix composite |
| CN112111700A (en) * | 2020-09-02 | 2020-12-22 | 上海交通大学 | Online quenching heat treatment method for nano-carbon reinforced aluminum alloy composite extruded section |
| CN112024896A (en) * | 2020-10-16 | 2020-12-04 | 湘潭大学 | Preparation method of CNTs-ZA27 zinc-aluminum-based composite bar with high C content |
| CN112024896B (en) * | 2020-10-16 | 2023-03-28 | 湘潭大学 | Preparation method of CNTs-ZA27 zinc-aluminum-based composite bar with high C content |
| CN113373341A (en) * | 2021-06-18 | 2021-09-10 | 苏州第一元素纳米技术有限公司 | Manufacturing process of carbon nano tube reinforced aluminum electric power fitting |
| CN113684391A (en) * | 2021-08-20 | 2021-11-23 | 中国兵器科学研究院宁波分院 | Preparation method of high-performance aluminum alloy and composite material thereof |
| CN113684391B (en) * | 2021-08-20 | 2022-05-27 | 中国兵器科学研究院宁波分院 | Preparation method of high-performance aluminum alloy and composite material thereof |
| CN114950649A (en) * | 2022-04-29 | 2022-08-30 | 中国人民解放军总医院第三医学中心 | Constant-low-temperature grinding device and method for preparing micron-sized biological hard tissue material |
| CN114950649B (en) * | 2022-04-29 | 2024-04-09 | 中国人民解放军总医院第三医学中心 | Constant low-temperature grinding device and method for preparing micron-sized biological hard tissue material |
| CN115261689A (en) * | 2022-07-29 | 2022-11-01 | 苏州第一元素纳米技术有限公司 | Light aluminum alloy composite material and preparation method and application thereof |
| CN116497250A (en) * | 2023-06-27 | 2023-07-28 | 有研工程技术研究院有限公司 | High-modulus aluminum-based composite foil and preparation method thereof |
| CN116497250B (en) * | 2023-06-27 | 2023-10-27 | 有研工程技术研究院有限公司 | High-modulus aluminum-based composite foil and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106544537B (en) | 2018-04-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106544537B (en) | A kind of preparation method of carbon nanotube enhanced aluminium-based composite material | |
| CN106312057B (en) | Powder metallurgy preparation method of nano-particle reinforced superfine crystal metal matrix composite material | |
| Singla et al. | CNT reinforced aluminium matrix composite-a review | |
| Munir et al. | Improving the strengthening efficiency of carbon nanotubes in titanium metal matrix composites | |
| CN109554565B (en) | Interface optimization method of carbon nanotube reinforced aluminum matrix composite | |
| CN109338167B (en) | Preparation method of carbon nano tube composite material | |
| Hao et al. | Effect of mechanical alloying time and rotation speed on evolution of CNTs/Al-2024 composite powders | |
| CN102424919A (en) | Method for preparing carbon nanotube reinforced aluminum-based composite material | |
| CN108396168A (en) | A kind of preparation method of high-strength highly-conductive creep resistant graphene enhancing aluminum alloy materials | |
| CN103602843A (en) | Carbon-nanotube-reinforced aluminum-base composite material | |
| Zheng et al. | Graphene nano-platelets reinforced aluminum composites with anisotropic compressive properties | |
| CN110157931B (en) | Nano carbon reinforced metal matrix composite material with three-dimensional network structure and preparation method thereof | |
| CN106399880A (en) | Preparation method for whisker carbon nanotube-reinforced aluminum matrix composite coated with aluminum oxide | |
| Zheng et al. | Achieving homogeneous distribution of high-content graphene in aluminum alloys via high-temperature cumulative shear deformation | |
| CN105063405A (en) | Preparation method of copper matrix graphene alloy | |
| CN110125389A (en) | A kind of preparation method of copper-graphite alkene collaboration reinforced aluminum matrix composites | |
| CN109439964A (en) | Carbon nanotube-graphene collaboration reinforced aluminum matrix composites mechanical property preparation method | |
| Chen et al. | Effect of spark-plasma-sintering conditions on tensile properties of aluminum matrix composites reinforced with multiwalled carbon nanotubes (MWCNTs) | |
| CN105112710A (en) | Copper-based graphene alloy | |
| Babu et al. | Sintering behaviour of copper/carbon nanotube composites and their characterization | |
| Li et al. | Microstructure and mechanical properties of magnesium matrix composite reinforced with carbon nanotubes by ultrasonic vibration | |
| CN110669956A (en) | Preparation method of carbon nano tube reinforced aluminum-based composite material with surface coated with aluminum oxide | |
| CN111057923B (en) | GR/N-SiCPComposite reinforced magnesium-based composite material and preparation method thereof | |
| CN109652679B (en) | Carbon nanotube and endogenous nano TiC particle mixed reinforced aluminum-based composite material and preparation method thereof | |
| CN112030044B (en) | Carbon nano tube reinforced aluminum matrix composite material and preparation method thereof |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |