Ti-Al intermetallic compound micro-laminated composite armor and preparation method thereof
Technical Field
The invention belongs to the technical field of armor protection, and particularly relates to a Ti-Al intermetallic compound micro-laminated composite armor and a preparation method thereof.
Background
With the rapid development of science and technology, the threat of personnel and equipment on the battlefield is larger and larger, the requirement on the performance of armor protection materials is higher and higher, and the armor materials are developing towards the directions of high hardness, high strength, high toughness and low density at present. Ti-Al3The Ti laminated composite material integrates the ductile metal Ti and the brittle intermetallic compound Al3The Ti has the advantages of excellent performances of low density, high modulus and high fracture toughness, and has great application prospect in the field of armor protection. It is worth noting that: due to Al3Greater difference in thermal expansion coefficient between Ti and Ti, Ti-Al3During the process of cooling the Ti laminated composite material from the preparation temperature to the room temperature, large thermal residual stress is inevitably generated. The residual stress can in turn lead to Ti-Al3A great number of tunnel cracks are generated inside the Ti laminated composite material, and the mechanical property of the Ti laminated composite material is further deteriorated. In addition, Ti-Al is affected by the Cokendall effect3Defects such as holes, peeling cracks and the like are easy to generate in the preparation process of the Ti laminated composite material. Preparation of Ti-Al by endothermic semi-solid reaction3The Ti-Al composite material can completely avoid Ti-Al3Tunnel crack, peeling crack, hole and other defects in the Ti laminated composite material. In addition, the Ti-AlTi laminated composite material is prepared by adopting high-temperature solid-liquid reactionAnd the defects of cracks, cavities and the like can be avoided by applying larger pressure in the later reaction stage.
Carrying out Ti-Al3In ballistic penetration experiments of Ti-Al laminated composite armor, it was found that when the initial velocity of the body was near or above that of Ti-Al3When the ballistic performance of the Ti-Al laminated composite material is limited, the damage form of the back surface of the target plate is petal-shaped cracking, which shows that the target plate absorbs huge energy in the process of resisting penetration of the shot, as shown in figure 1. However, the diameter of the target plate front surface crater is the same as that of the shot and plastic deformation occurs, which indicates that Ti-Al3The hardness of the Ti-Al laminated composite material is lower than that of the shot.
In ballistic penetration experiments of Ti-AlTi laminated composite armor, ceramic cones appeared on the back of the target plate when the initial velocity of the projectile was near or above the ballistic limit of the Ti-AlTi laminated composite, as shown in fig. 2. The composite material is a brittle failure mode, which shows that the Ti-AlTi laminated composite material has higher hardness and better fragment penetration resistance on the bullet-facing surface, and plays a larger role in buffering and inhibiting the fragment impact kinetic energy.
Ti-Al3The Ti-Al laminated composite armor has lower hardness and rigidity and poor fragment penetration resistance on the bullet-facing surface, but petal-type cracking on the back surface of the target plate shows that the armor has the characteristic of high energy absorption. The Ti-AlTi laminated composite armor has high hardness and rigidity, good fragment penetration resistance of the bullet-facing surface and large buffer inhibition effect on fragment impact kinetic energy.
Disclosure of Invention
The invention provides a Ti-Al intermetallic compound micro-laminated composite armor and a preparation method thereof, aiming at improving the penetration resistance of the titanium-aluminum intermetallic compound laminated composite armor.
The invention is realized by adopting the following technical scheme: the Ti-Al intermetallic compound micro-laminated composite armor is prepared from Ti-AlTi and Ti-Al3Ti-Al intermetallic compound micro-laminated composite armor consisting of Ti-Al laminated composite material, wherein: Ti-AlTi laminated composite material as front plate of armour, Ti-Al3The Ti-Al laminated composite material is used as an armor rear plate, and the armor front plate and the armor rear plate are connected in a diffusion welding mode; armored front plate and armored rear plateThe thickness ratio of (A) to (B) is 3:1 to 4: 1.
The method for preparing the Ti-Al intermetallic compound micro-laminated composite armor comprises the steps of preparing Ti-AlTi and Ti-Al by a vacuum hot-pressing sintering method3Ti-Al two laminated composite materials, and then adding Ti-AlTi and Ti-Al3And welding the Ti-Al laminated composite materials together in a diffusion welding mode to obtain the Ti-Al intermetallic compound micro-laminated composite armor.
The specific preparation method of the Ti-AlTi laminated composite material comprises the following steps:
(1) acid-base cleaning TC4Al foil: mixing TC4Cutting the foil and the Al foil into the same size; cutting TC4Placing the foil into an acid solution prepared from HF and water at a volume ratio of 1:20 for treatment, and placing the cut Al foil into a 5% NaOH solution for treatment, wherein the reaction time of the two is 2min, so as to remove surface oxides of the Al foil; washing the two reacted foils with clear water; ultrasonically cleaning the two foils for 5min by using alcohol, and finally drying the two foils for later use;
(2) laminating and sheathing: TC to be prepared4Foil, Al foil according to TC4-Al-TC4The lamination thickness is 7-10mm, and the outermost layer is TC4Layer, using TC of 20 μm thickness for the laminated sample4Packaging the foil to obtain a packaging body;
(3) vacuum hot-pressing sintering: placing the obtained packaging body in a graphite mold, and carrying out vacuum hot-pressing sintering according to the following process to obtain the Ti-AlTi laminated composite material;
A. applying 3-5MPa pressure to the obtained packaging body, raising the sintering temperature to 580-610 ℃ at the speed of 20 ℃/min, and then preserving heat for 200 min, wherein the pressure during the heat preservation is 3-5 MPa;
B. unloading the loaded pressure, raising the sintering temperature to 1300 ℃ at the speed of 20 ℃/min, preserving the heat for 150min at the temperature of 1100-;
C. reducing the sintering temperature to 610 ℃ at the rate of 10 ℃/min, and preserving the heat for 150min at the temperature of 580-;
D. cooling along with the furnace, wherein the pressure is 2-3MPa during cooling, and demolding to prepare the Ti-AlTi laminated composite material.
The Ti-Al3The specific preparation method of the Ti-Al laminated composite material comprises the following steps:
(1) acid-base cleaning TC4Al foil: mixing TC4Cutting the foil and the Al foil into the same size; cutting TC4Placing the foil into an acid solution prepared from HF and water at a volume ratio of 1:20 for treatment, and placing the cut Al foil into a 5% NaOH solution for treatment, wherein the reaction time of the two is 2min, so as to remove surface oxides of the Al foil; washing the two reacted foils with clear water; ultrasonically cleaning the two foils for 5min by using alcohol, and finally drying the two foils for later use;
(2) laminating and sheathing: TC to be prepared4Foil, Al foil according to TC4-Al-TC4The lamination thickness is 5-7 mm, and the outermost layer is ensured to be TC4Layer, using TC of 20 μm thickness for the laminated sample4Packaging the foil to obtain a package body;
(3) vacuum hot-pressing sintering: placing the obtained packaging body in a graphite mold, and carrying out vacuum hot-pressing sintering according to the following process to obtain the Ti-Al3Ti-Al laminated composite material:
a. applying 3-5MPa pressure to the obtained packaging body, raising the sintering temperature to 610 ℃ at the speed of 20 ℃/min, and preserving the temperature for 60-100min, wherein the pressure during the heat preservation is 3-5 MPa;
b. raising the sintering temperature to 640 ℃ at the speed of 5 ℃/min, and preserving the heat for 400min, wherein the pressure during the heat preservation is 2-3 Mpa;
c. reducing the sintering temperature to 570 ℃ at the speed of 5 ℃/min, and preserving the heat for 180min, wherein the pressure during the temperature reduction and preservation is 2-3 MPa;
d. cooling along with the furnace, the pressure is 2-3MPa during cooling, and demoulding to prepare the Ti-Al3Ti-Al laminated composite material.
The specific preparation method of the Ti-Al intermetallic compound micro-laminated composite armor comprises the following steps:
(1) mixing the prepared Ti-AlTi and Ti-Al3Polishing the surface layer of the Ti-Al laminated composite material by using sand paper until fresh TC is exposed4Surface, standby;
(2) cutting the aluminum foil into the same size, and putting the cut Al foil into a 5% NaOH solution for treatment, wherein the reaction time is 2min, so as to remove the surface oxide of the aluminum foil; washing the reacted Al foil with clear water; ultrasonically cleaning the Al foil for 5min by using alcohol, and finally drying the Al foil for later use;
(3) placing the treated Al foil on the prepared Ti-AlTi and Ti-Al3The Ti-Al laminated composite material is internally provided with TC with the thickness of 20 mu m4The foil encapsulates the whole;
(4) placing the packaging body in a graphite mold, and performing diffusion welding connection in a vacuum hot-pressing sintering furnace according to the following process:
applying 4-6 MPa pressure to the obtained packaging body, raising the sintering temperature to 660 ℃ at the speed of 20 ℃/min, and then preserving heat for 20min, wherein the pressure during the heat preservation is 4-6 MPa;
cooling along with the furnace, wherein the pressure is 1-2 MPa during cooling, and demolding to prepare the Ti-Al intermetallic compound micro-laminated composite armor.
The thickness of the Al foil is 0.1-0.2 mm; the thickness ratio of the Al foil to the TC4 foil is 1:3-2: 3. The TC4The foil, Al foil and aluminum foil 0.2mm thick were cut out to 100X 100 mm.
The invention adopts a new structure mode and consists of a front plate and a rear plate, wherein the front plate is made of Ti-AlTi laminated composite material with high hardness, and the rear plate is made of Ti-Al laminated composite material with high toughness3The front plate and the rear plate of the Ti-Al laminated composite material are connected by adopting a diffusion welding method. The composite armor has the advantages of fully utilizing the performance advantages of different materials and greatly improving the penetration resistance of the composite armor. The front plate of the composite armor is made of a low-density high-hardness Ti-AlTi laminated composite material, the anti-fragment penetration capability of the bullet-facing surface of the front plate is good, and the front plate plays a large role in buffering and inhibiting fragment impact kinetic energy; from low-density high-toughness Ti-Al3The Ti-Al laminated composite material is used as a back plate of the composite armor, so that the impact kinetic energy of fragments is fully absorbed, and the penetration resistance of the composite armor is improved. In addition, materials of all layers are metallurgically bonded, the interface bonding strength is high, and the integrity of the composite armor structure can be ensured when the composite armor is impacted by a projectile.
The front plate of the composite armor is a Ti-AlTi laminated composite material, and the rear plate is Ti-Al3The Ti-Al laminated composite material can effectively disperse the impact force of the projectile when the composite armor front plate is impacted by the projectile, resist the penetration of the projectile, effectively absorb the impact force transmitted by the front plate in the penetration process of the projectile by the rear plate, maintain the integrity of the composite armor structure and effectively improve the penetration resistance of the laminated composite armor.
Drawings
FIG. 1 shows Ti-Al3The ballistic penetration of the Ti-Al laminated composite material target plate and the failure of the back surface of the target plate are shown schematically;
FIG. 2 is a schematic diagram of ballistic penetration of a Ti-AlTi laminated composite target plate and target plate backside failure.
Detailed Description
In order to further clarify the technical solutions and effects of the present invention, the present invention is further described with reference to the following specific examples.
Example 1: the Ti-Al intermetallic compound micro-laminated composite armor is prepared from Ti-AlTi and Ti-Al3Ti-Al intermetallic compound micro-laminated composite armor consisting of Ti-Al laminated composite material, wherein: Ti-AlTi laminated composite material as front plate of armour, Ti-Al3The Ti-Al laminated composite material is used as an armor rear plate, and the armor front plate and the armor rear plate are connected in a diffusion welding mode; the thickness ratio of the front plate to the rear plate is 3: 1.
The specific preparation method of the Ti-AlTi laminated composite material comprises the following steps:
(1) acid-base cleaning TC4Al foil: mixing 0.15mm thick TC4Cutting foil and 0.1mm thick Al foil according to 100 × 100mm size; cutting TC4The foil is put into an acid solution prepared by HF and water according to the volume ratio of 1:20 for treatment, and the cut Al foil is put into a 5 percent NaOH solutionTreating in liquid for 2min to remove surface oxide; washing the two reacted foils with clear water; ultrasonically cleaning the two foils with alcohol for 5min, and drying the two foils for use
(2) Laminating and sheathing: TC to be prepared4Foil, Al foil according to TC4-Al-TC4The laminated layer number is 65, and the outermost layer is ensured to be TC4Layer, using TC of 20 μm thickness for the laminated sample4And (7) packaging the foil.
(3) Vacuum hot-pressing sintering: placing the obtained packaging body in a graphite mold, and carrying out vacuum hot-pressing sintering according to the following process to obtain the Ti-AlTi laminated composite material:
A. applying 3.8 MPa pressure to the obtained packaging body, raising the sintering temperature to 600 ℃ at the speed of 20 ℃/min, and then preserving heat for 180min, wherein the pressure during the heat preservation is 3.8 MPa;
B. unloading the loaded pressure, increasing the sintering temperature to 1100 ℃ at the speed of 20 ℃/min, preserving the temperature for 120min, not applying the pressure in the early stage of heat preservation, and applying the pressure of 2Mpa in the later 30 min;
C. reducing the sintering temperature to 600 ℃ at the speed of 10 ℃/min, and preserving the temperature for 120min, wherein the pressure during the temperature reduction and preservation is 2 MPa;
D. cooling along with the furnace, wherein the pressure is 2MPa during cooling, and demolding to prepare the Ti-AlTi laminated composite material.
Ti-Al3The specific preparation method of the Ti-Al laminated composite material comprises the following steps:
(1) acid-base cleaning TC4Al foil: mixing 0.15mm thick TC4Cutting foil and 0.1mm thick Al foil according to 100 × 100mm size; cutting TC4Placing the foil into an acid solution prepared from HF and water at a volume ratio of 1:20 for treatment, and placing the cut Al foil into a 5% NaOH solution for treatment, wherein the reaction time of the two is 2min, so as to remove surface oxides of the Al foil; washing the two reacted foils with clear water; and ultrasonically cleaning the two foils for 5min by using alcohol, and finally drying the two foils for later use.
(2) Laminating and sheathing: TC to be prepared4Foil, Al foil according to TC4-Al-TC4The laminated layer number is 45, and the outermost layer is ensured to be TC4Layer, using TC of 20 μm thickness for the laminated sample4And (7) packaging the foil.
(3) Vacuum hot-pressing sintering: placing the obtained packaging body in a graphite mold, and carrying out vacuum hot-pressing sintering according to the following process to obtain the Ti-Al3Ti-Al laminated composite material:
A. applying 3.8 MPa pressure to the obtained packaging body, raising the sintering temperature to 600 ℃ at the speed of 20 ℃/min, and then preserving heat for 60 min, wherein the pressure during the heat preservation is 3.8 MPa;
B. raising the sintering temperature to 640 ℃ at the speed of 5 ℃/min, and preserving the heat for 400min, wherein the pressure is 3Mpa during the heat preservation period; reducing the sintering temperature to 570 ℃ at the speed of 5 ℃/min, and preserving the temperature for 120min, wherein the pressure during the temperature reduction and preservation is 2 MPa;
C. cooling along with the furnace, the pressure during cooling is 2MPa, and demoulding to prepare the Ti-Al3Ti-Al laminated composite material.
Diffusion welding Ti-AlTi and Ti-Al3Ti-Al laminated composite material:
(1) mixing the prepared Ti-AlTi and Ti-Al3Polishing the surface layer of the Ti-Al laminated composite material by using sand paper until the surface of fresh TC4 is exposed for later use;
(2) cutting 0.2mm thick aluminum foil according to 100 × 100mm size, and treating the cut Al foil in 5% NaOH solution for 2min to remove surface oxide; washing the reacted Al foil with clear water; ultrasonically cleaning the Al foil for 5min by using alcohol, and finally drying the Al foil for later use;
(3) placing the treated Al foil on the prepared Ti-AlTi and Ti-Al3The Ti-Al laminated composite material is internally provided with TC with the thickness of 20 mu m4The foil encapsulates the whole;
(4) placing the packaging body in a graphite mold, and performing diffusion welding connection in a vacuum hot-pressing sintering furnace according to the following process:
a. applying 6 MPa pressure to the obtained packaging body, raising the sintering temperature to 660 ℃ at the speed of 20 ℃/min, and then preserving heat for 20min, wherein the pressure during the heat preservation is 6 MPa;
b. cooling along with the furnace, wherein the pressure is 2MPa during cooling, and demoulding to prepare the intermetallic compound composite armor with the new structure.
Example 2: the first difference between the present embodiment and the specific embodiment is: TC (tungsten carbide)4The thickness of the foil was 0.3mm, the thickness of the Al foil was 0.2mm, and the other steps and parameters were the same as in the first embodiment.
Example 3: the first difference between the present embodiment and the specific embodiment is: the maximum temperature for preparing the Ti-AlTi laminated composite material is 1300 ℃, and other steps and parameters are the same as those of the first embodiment.
The Ti-Al intermetallic compound micro-laminated composite armor prepared by the invention has excellent penetration resistance. The composite target plate prepared in example 1 was subjected to a ballistic penetration test, a 9.5mm tungsten alloy fragment shooting test was performed on the composite target plate using a 10mm bore smoothbore gun, and the fragment speed was controlled by the charge amount. The range is 6 m, normal incidence. The ballistic limit V50 of the Ti-Al intermetallic compound micro-laminated composite target plate is obtained by a plurality of tests.
TABLE 1 ballistic penetration test data for Ti-Al intermetallic compound micro-laminated composite target plate
In a penetration test, the initial impact speed of the tungsten alloy fragments is controlled by changing the loading amount. The validity tests are carried out for 5 times in total, and the initial impact speed ranges of the projectile bodies are obtained to be 501 m/s, 485 m/s, 529 m/s, 562m/s and 538 m/s. As can be seen from Table 1, the lowest initial velocity of the tungsten alloy fragments penetrating through the Ti-Al intermetallic compound micro-laminated target plate is 562m/s, and the highest initial velocity of the tungsten alloy fragments not penetrating through the Ti-Al intermetallic compound micro-laminated target plate is 538m/s, so that the ballistic limit of the tungsten alloy fragments penetrating through the Ti-Al intermetallic compound micro-laminated target plate is 538 m/s-562 m/s.
The average value of the data of the 4 th group and the 5 th group is about 550 m/s of the ballistic limit V50 of the Ti-Al intermetallic compound micro-laminated composite target plate. Under the same test conditions, the ballistic limit V50 of the Q235 steel sheet obtained was about 522 m/s. Therefore, the protective capability of the Ti-Al intermetallic compound micro-laminated composite armor is higher than that of Q235 steel, and the density of the Ti-Al intermetallic compound micro-laminated composite armor is far lower than that of the Q235 steel, so that the Ti-Al intermetallic compound micro-laminated composite armor has a huge application prospect.