磁控溅射制备火炮身管材料表面氮化物膜层技术研究

发布时间：2018-01-14 06:17

本文关键词：磁控溅射制备火炮身管材料表面氮化物膜层技术研究　出处：《沈阳工业大学》2017年博士论文　论文类型：学位论文

【摘要】：火炮在发射过程中,身管内膛为高温高压的火药气体工况,同时弹带与内膛表面存在剧烈的摩擦磨损,另外在海洋等气候条件下,身管受到剧烈的盐气腐蚀作用,因此火炮身管内膛表面抗高温氧化性能、耐磨损性能和耐盐气腐蚀性能是衡量其性能的重要指标。随着对火炮射击远程化的要求,更高能量的发射药应用于火炮系统中,传统的电镀铬已经越来越不能满足炮管内膛的工况要求。为了提高火炮身管内膛的性能,需要开发新的膜层制备技术和膜层材料。本文在综合分析国内外火炮身管延寿技术的基础上,从膜层制备来提高火炮身管材料表面性能的角度出发,首次采用磁控溅射技术在火炮身管材料PCrNi_3Mo钢表面施镀CrAlN膜层,并在此基础上添加稀有金属V元素来进一步改善膜层的综合性能,通过对所制备膜层硬度与弹性模量、摩擦磨损、抗高温氧化、耐腐蚀性能的测试与分析,综合确定了合理的膜层制备工艺,以此为火炮身管延寿技术提供理论参考。本研究取得了如下的研究成果:(1)工艺参数对磁控溅射膜层性能的影响:溅射膜层过程中,未施加基体负偏压情况下,膜层结构疏松并出现明显的斑点缺陷,当施加50-100V偏压时,由于溅射粒子能量提高,膜层表面平整致密,继续增加负偏压至150V时,溅射粒子对膜层表面轰击作用增强而导致膜层表面损伤,随着负偏压增至200V、300V,表面损伤越发严重而造成膜层表面质量下降,其中施加100V偏压的膜层具有最佳的表面质量;溅射电流在0.1-0.2A范围内变化时,随着溅射电流的增大,溅射速率增大,同时由于溅射粒子能量的增加,导致膜层平整致密,力学性能提高,溅射电流在0.2-0.4A范围内变化时,由于过高的粒子能量轰击表面使得表面损伤,同时,过高的溅射电流使得Cr粒子能量与数量增加,未被氮化的Cr以单质Cr的形式存在于膜层中,导致膜层力学性能下降,其中溅射电流为0.2A时膜层具有最佳的表面质量和力学性能;当N_2/Ar3/4时,由于部分Cr原子未被氮化,随着N_2流量的增加,膜层硬度和弹性模量增大,当N_2/Ar流量比达到1的时候,Cr原子完全被氮化,膜层硬度和弹性模量达到最高,当继续增大N_2/Ar流量比的时候,膜层的硬度和弹性模量开始略微降低。在负偏压100V,溅射电流0.2A,N_2/Ar流量比为1时溅射的CrN膜层质量最佳,其硬度和弹性模量分别为21.38GPa和272.71GPa。(2)CrAlN与CrAlVN膜层的制备与力学性能:通过控制Al靶功率(50-200W),制备出不同Al含量的CrAlN膜层,所制备膜层表面均为“菜花状”结构,断口显示出典型的柱状晶结构。Al的引入细化了晶粒,在一定范围内起到了固溶强化的作用,其中Cr0.34Al0.66N膜层具有最佳的硬度与弹性模量,分别为23.91GPa和316.2GPa,其摩擦系数为0.293;通过控制V靶电流(0.03-0.09A),制备出不同V含量的CrAlVN膜层,稀有金属V元素的引入使得晶粒细化越发明显,V固溶在CrAlN膜层中导致晶格发生变化进而引起固溶强化,致使膜层表面更加平整而致密,柱状晶间距减小,结构更加致密。其中Cr0.31Al0.62V0.07N膜层具有最佳的硬度与弹性模量,分别为24.98GPa和336.02GPa,摩擦系数降低至0.186。(3)炮钢基体、CrAlN与CrAlVN膜层抗氧化性能:炮钢在空气中500℃氧化10小时后表面形成Fe_3O_4和Fe_2O_3两种氧化物,600℃、700℃氧化10小时后表面形成FeO、Fe_3O_4和Fe_2O_3三种氧化物,其中700℃时表面氧化膜出现大量分层和剥落。CrAlN膜层在750℃、850℃下空气中氧化20小时后,表面形成了以Al_2O_3为主的氧化膜,750℃氧化后膜层内部除了主要含有fcc结构的CrN外,还有少量的纤维锌矿结构的w-AlN;850℃氧化后膜层中相结构由CrN、Cr_2N和Cr组成。在950℃下恒温氧化20小时后,表面主要形成了以Fe_3O_4和Fe_2O_3为主的氧化物;CrAlVN膜层在750℃、850℃和950℃下空气中氧化20小时后,表面形成了以Al_2O_3为主的氧化膜,随着温度的提高,其表面V的氧化物按AlVO4→V3O7→VO2转变,膜层中的相一直保持fcc-CrN结构。V的加入抑制了膜层中柱状晶的长大,使膜层中的晶粒细化尺寸约为7nm,提高了膜层的抗高温氧化性能,延缓了基体元素Fe向膜层中的扩散,稳定了膜层中的相结构。随着氧化温度的提高,CrAlN膜层的硬度和弹性模量下降很快;而CrAlVN膜层仅有小幅下降,经950℃下恒温氧化20小时后,CrAlVN膜层的硬度和弹性模量分别为20.82GPa和314.6GPa,较沉积态分别仅下降了16.7%和6.4%。(4)炮钢基体、CrAlN与CrAlVN膜层耐腐蚀性能:PCrNi_3Mo钢在3.5%NaCl溶液中发生活性溶解,表面腐蚀产物不具有保护作用;CrAlN与CrAlVN膜层均提高了PCrNi_3Mo钢的耐腐蚀性能,并存在钝化现象。CrAlN和CrAlVN膜层均使PCrNi_3Mo钢的阴极反应得到抑制。CrAlVN膜层表现出更为优异的防护效果,源于其均匀而致密的微观结构。
[Abstract]:The gun during the firing process, bore propellant gas for high temperature and high pressure conditions, and projectile severe friction and wear with the inner surface, also in the ocean climate conditions, tube corrosion by salt gas dramatically, so the gun barrel bore surface oxidation resistance, abrasion resistance the performance of corrosion resistance and salt gas is an important indicator to measure the performance of firing distance. With the requirements of higher energy propellant used in gun system, traditional chromium plating has been increasingly unable to meet the requirements of artillery bore condition. In order to improve the performance of the gun bore. Need to develop a new film preparation technology and coating materials. Based on the comprehensive analysis of domestic and foreign gun barrel life extension technology, from the angle of film preparation to improve the surface properties of gun barrel of the magnetron sputtering technology In the gun tube material PCrNi_3Mo steel surface plating CrAlN coating, comprehensive performance and on the basis of adding rare metal elements V to further improve the film, the film hardness and elastic modulus, friction and wear, high temperature oxidation resistance, corrosion resistance test and comprehensive analysis, to determine a reasonable coating system the preparation process, so as to provide theoretical reference for gun tube life extension technology. The research results are obtained as follows: (1) the influence of technological parameters on the film properties of magnetron sputtering: sputtering coating process, without substrate bias conditions applied, film structure and loose spots appeared obvious defects, when applying the 50-100V bias when the particle energy is increased due to sputtering, coating surface smooth and dense, continue to increase the negative bias to 150V, sputtering particles on the film surface bombardment increased film surface damage, with a negative bias to 200V, 300V, surface damage caused by more serious decline in the quality of coating surface, the coating surface quality by applying the 100V bias is the best; the sputtering current varies in the range of 0.1-0.2A, with the increase of sputtering current, the sputtering rate increases due to the increase of sputtering energy of particles, resulting in film is compact and smooth, improve mechanical properties, sputtering the current changes in the range of 0.2-0.4A, because of the high energy particle bombardment surface makes the damage, at the same time, the increase of Cr sputtering current high energy and particle number has not been nitrided Cr exists in the form of elemental Cr in the film, resulting in a decline in mechanical properties of film, wherein the sputtering current of 0.2A film with surface quality and the best mechanical properties; when N_2/Ar3/4, the Cr atoms are not nitride, with the increase of N_2 flow rate, increasing the hardness and elastic modulus, when the flow of N_2/Ar The amount is more than 1 when the Cr atom is completely nitride, film hardness and elastic modulus reached the highest when continues to increase when N_2/Ar flow ratio, hardness and elastic modulus of the film began to decreased slightly. In the negative bias voltage of 100V, sputtering current of 0.2A, the flux ratio of N_2/Ar is 1 when the sputtering CrN film quality is best, its hardness and the elastic modulus were 21.38GPa and 272.71GPa. (2) preparation and mechanical properties of CrAlN and CrAlVN film: by controlling the power of the Al target (50-200W), were prepared with different Al content CrAlN films, prepared by coating on the surface are the "cauliflower" structure, the fracture showed a columnar structure of typical.Al the introduction of the grain refinement in a certain range of the solution strengthening the role of the Cr0.34Al0.66N film has the best hardness and elastic modulus, respectively 23.91GPa and 316.2GPa, the friction coefficient is 0.293; through the control of V target current (0.03-0.09A ), were prepared with different V content CrAlVN film, introducing rare metal element V makes the grain refinement is more and more obvious, V solid solution crystal lattice changes caused by the solid solution strengthening in CrAlN film, the film surface more smooth and dense, columnar crystal spacing decreases, the structure is more compact. The film has a hardness of Cr0.31Al0.62V0.07N with the optimal elastic modulus, respectively 24.98GPa and 336.02GPa, the friction coefficient is reduced to 0.186. (3) gun steel matrix, the oxidation resistance of CrAlN and CrAlVN film: gun steel in the air oxidation of 500 DEG C after 10 hours of Fe_3O_4 and Fe_2O_3 formed on the surface of two kinds of oxides formed on the surface of FeO, 600 C, 700 C 10 hours after oxidation. Fe_3O_4 and Fe_2O_3 three kinds of oxides, the oxide film on the surface of 700 DEG C, the emergence of a large number of delamination and spalling of.CrAlN film at 750 C, 850 C in air oxidation after 20 hours, formed on the surface of oxide based on Al_2O_3 Film, 750 DEG C after oxidation film inside in addition to the main structure of CrN containing FCC, and a small amount of wurtzite w-AlN; 850 DEG C after oxidation film phase structure by CrN, Cr_2N and Cr. In 950 c oxidation after 20 hours, the surface mainly formed by Fe_3O_4 and Fe_2O_3 based oxides CrAlVN film; at 750 degrees, 850 degrees and 950 degrees in air oxidation after 20 hours, formed on the surface of Al_2O_3 film, with the increase of temperature, the surface oxide of V by AlVO4 - V3O7 - VO2 transformation in the coating phase has been kept restrained the growth of columnar crystal film fcc-CrN the structure of.V, the film grain refinement size is about 7Nm, improves the oxidation resistance of the coatings, delaying the diffusion matrix elements Fe to film in the stable phase structure in the films. With the increasing oxidation temperature, hardness and elastic film layer CrAlN Modulus decreased rapidly; while the CrAlVN film only slightly decreased, the isothermal oxidation under 950 DEG C for 20 hours, the hardness and elastic modulus of CrAlVN film were 20.82GPa and 314.6GPa, were deposited respectively decreased by only 16.7% and 6.4%. (4) gun steel substrate, the corrosion resistance of CrAlN and CrAlVN film: PCrNi_3Mo steel hair life is dissolved in 3.5%NaCl solution, the corrosion product has no protective effect; CrAlN and CrAlVN film improves the corrosion resistance of PCrNi_3Mo steel, and the presence of.CrAlN and CrAlVN film passivation of the cathode reaction of PCrNi_3Mo steel to inhibit.CrAlVN film exhibits more excellent protective effect, due to its uniform dense microstructure.

【学位授予单位】：沈阳工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TJ304;TG174.4

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