WUT超音速表面喷涂技术
超音速喷涂技术是热喷涂领域中以超高速（可达 1000m/s 以上）气流驱动熔融或半熔融粉末撞击基体表面形成高性能涂层的先进技术。其核心优势在于涂层致密度高、结合强度大、热影响区小，表面强化效果明显。
一、技术原理
超音速喷涂的本质是通过高能热源（燃烧或电弧）将粉末材料加热至塑性或熔融状态，再借助超音速气流（通过拉瓦尔喷嘴加速）将粉末颗粒高速喷射到待处理基体表面，颗粒撞击后发生塑性变形、堆叠并快速冷却凝固，最终形成与基体紧密结合的涂层。整个过程分为三个关键阶段：粉末加热与加速、颗粒撞击与变形、涂层固化与结合与基体形成高强度涂层。
二、技术核心与优势
超音速喷涂技术通过超高速粒子赋予涂层的高致密度、高强度和低缺陷特性，使其成为高端装备（航空航天、能源、精密机械）实现长寿命、高可靠性的关键技术，尤其在传统技术难以应对的极端工况（如高温、高磨损、强腐蚀）中，优势更为显著。
1.涂层性能卓越，性能指标优越：涂层致密度极高，接近锻件水平。极低的孔隙率大幅减少腐蚀介质、磨损颗粒的侵入通道，显著提升涂层的抗腐蚀、抗磨损能力。结合强度高，涂层不易剥落，高速粒子撞击时产生强烈的机械嵌合与扩散结合，涂层与基体的结合强度可达50-150MPa，涂层不易出现分层或剥落，可靠性显著提升。
2.对基体损伤小，适用范围更广：热影响区（HAZ）极小，超音速喷涂的粒子温度控制在 “塑性区间”（避免完全熔融），且高速气流对基体有冷却作用，基体受热温度通常低于 200℃，热影响区仅＜50μm，基体材料的相变、软化、变形等可忽略，尤其适合热处理强化钢、铝合金、钛合金等热敏感材料时。
3.涂层氧化与烧损少，材料性能保留更完整：氧化程度低，涂层成分更纯净，粒子在高温区停留时间极短（＜1ms），且超音速气流形成的 “气障” 可减少与空气的接触，显著降低材料氧化（如 NiCr 合金涂层的氧化量比等离子喷涂减少 60% 以上）。对于易氧化的金属（如铝、铜）或碳化物（如 WC），能有效避免生成脆性氧化相（如 WO₃），保证涂层韧性。
4.粉末材料利用率高，性能发挥充分：粒子加速充分，飞行方向更集中，粉末利用率可达50%-70%。同时，低温高速的特性可保留粉末的原始优良性能，如纳米结构粉末的细化晶粒效应。
5.适用极端工况，延长装备寿命：耐磨：高致密度和高强度使涂层能承受高载荷滑动或冲蚀（如石油钻井钻头喷涂 WC-Co 涂层，寿命比未处理件延长 5 倍以上；耐蚀：低孔隙率配合耐腐蚀合金（如 NiCrMo），可在酸碱、海水等环境中长期使用，如海洋平台管道涂层寿命达 10 年以上；耐高温：通过选择 NiCrAlY 等高温合金，涂层可在 1000℃以上环境中抗氧化、抗热震（如航空发动机涡轮叶片涂层）。
三、典型应用
超音速喷涂凭借高性能涂层，在多个工业领域解决 “磨损、腐蚀、冲蚀、高温氧化” 等核心问题：
1.航空航天
发动机部件：涡轮叶片、燃烧室表面喷涂 NiCrAlY 抗氧化涂层（耐受 1000℃以上高温）；压气机叶片喷涂 WC-Co 耐磨涂层（抗沙尘冲蚀）；
起落架：表面喷涂 Cr₃C₂-NiCr 涂层（提升抗疲劳磨损性能，延长寿命 2-3 倍）。
2.石油化工
钻井设备：钻头、抽油杆喷涂 WC-Co 合金涂层（耐岩石磨损，寿命提升 5 倍以上）；
管道内壁：输送含砂原油的管道喷涂 Ni 基合金涂层（抗冲刷腐蚀，替代传统不锈钢）。
3.电力能源
汽轮机附件：叶片喷涂 Al₂O₃-TiO₂陶瓷涂层（抗蒸汽冲蚀）；阀门密封面喷涂 CoCrW 合金（耐磨 + 耐腐蚀）；
设备轴体：主轴轴承座喷涂 Fe 基合金涂层（修复磨损，降低更换成本 60%）。
4.机械制造
模具表面：冷作模具喷涂 CrN 涂层（提高硬度至 80HRC，延长冲压次数）；
液压元件：油缸内壁喷涂镍基合金涂层（替代镀铬，环保且耐磨性能更优。
WUT Supersonic Surface Spraying Technology
Supersonic spraying technology is an advanced thermal spraying method that uses ultra-high-speed gas streams (exceeding 1000 m/s) to propel molten or semi-molten powder particles onto substrate surfaces, forming high-performance coatings. Its core advantages include exceptional coating density, strong bonding strength, minimal heat-affected zones, and superior surface reinforcement.
I.Technical Principle
The process utilizes a high-energy heat source (combustion or electric arc) to heat powder materials to a plastic or molten state. Particles are then accelerated via a supersonic gas stream (generated by a Laval nozzle) and impact the substrate at high velocity. Upon collision, particles deform plastically, stack, and rapidly solidify, forming a dense coating tightly bonded to the substrate. Key stages include: powder heating/acceleration, particle impact/deformation, and coating solidification/bonding.
II.Core Advantages
Supersonic spraying technology endows coatings with high density, high strength, and low defect characteristics through ultra high speed particles, making it a key technology for achieving long life and high reliability in high-end equipment (aerospace, energy, precision machinery), especially in extreme working conditions that traditional technology cannot cope with (such as high temperature, high wear, and strong corrosion), the advantages are more significant.
1.Excellent coating performance and superior performance indicators: The coating has a very high density, close to the level of forgings. The extremely low porosity significantly reduces the invasion channels of corrosive media and wear particles, significantly improving the corrosion and wear resistance of the coating. High bonding strength, the coating is not easily peeled off, and strong mechanical and diffusion bonding occurs when high-speed particles collide. The bonding strength between the coating and the substrate can reach 50-150MPa, and the coating is not prone to delamination or peeling, significantly improving reliability.
2.Less damage to the substrate and wider applicability: the heat affected zone (HAZ) is extremely small, and the particle temperature of supersonic spraying is controlled in the "plastic zone" (to avoid complete melting). In addition, high-speed airflow has a cooling effect on the substrate, and the heating temperature of the substrate is usually below 200 ℃. The heat affected zone is only<50 μ m, and the phase transformation, softening, deformation, etc. of the substrate material can be ignored, especially when strengthening heat sensitive materials such as steel, aluminum alloy, and titanium alloy through heat treatment.
3.The coating has less oxidation and burning loss, and the material properties are preserved more completely: the degree of oxidation is low, the coating composition is purer, the particle residence time in the high temperature zone is extremely short (<1ms), and the "air barrier" formed by supersonic airflow can reduce contact with air, significantly reducing material oxidation (such as NiCr alloy coating, which reduces the oxidation amount by more than 60% compared to plasma spraying). For easily oxidizable metals (such as aluminum, copper) or carbides (such as WC), it can effectively avoid the formation of brittle oxidation phases (such as WO3) and ensure the toughness of the coating.
4.The utilization rate of powder materials is high, and their performance is fully utilized: the particle acceleration is sufficient, the flight direction is more concentrated, and the powder utilization rate can reach 50% -70%. At the same time, the low-temperature and high-speed characteristics can preserve the original excellent properties of the powder, such as the grain refinement effect of nanostructured powder.
5.Suitable for extreme working conditions, extending equipment life: Wear resistance: High density and strength enable the coating to withstand high load sliding or erosion (such as spraying WC Co coating on oil drilling bits, extending the life of untreated parts by more than 5 times); Corrosion resistance: Low porosity combined with corrosion-resistant alloys (such as NiCrMo) can be used for a long time in acidic, alkaline, seawater and other environments, with a coating life of more than 10 years for offshore platform pipelines; High temperature resistance: By selecting high-temperature alloys such as NiCrAlY, the coating can resist oxidation and thermal shock in environments above 1000 ℃ (such as coatings on aircraft engine turbine blades).
III.Industrial Applications
Supersonic spraying, with high-performance coatings, solves core problems such as wear, corrosion, erosion, and high-temperature oxidation in multiple industrial fields:
1.Aerospace:
Engine components: turbine blades, combustion chamber surface coated with NiCrAlY anti-oxidation coating (capable of withstanding high temperatures above 1000 ℃); Spray WC-Co wear-resistant coating on compressor blades (resistant to sand and dust erosion);
Landing gear: Surface sprayed with Cr₃C₂-NiCr coating (improves fatigue wear resistance and extends lifespan by 2-3 times).
2.Petrochemicals:
Drilling equipment: Drill bits and sucker rods coated with WC-Co alloy (resistant to rock wear, with a lifespan increase of more than 5 times);
Pipeline inner wall: The pipeline transporting sand containing crude oil is sprayed with Ni based alloy coating (anti erosion and corrosion, replacing traditional stainless steel).
3.Electric energy:
Steam turbine accessories: blades coated with Al₂O₃-TiO₂ ceramic coating (resistant to steam erosion); Valve sealing surface sprayed with CoCrW alloy (wear-resistant+corrosion-resistant);
Equipment shaft body: The main shaft bearing seat is coated with Fe based alloy coating (repairing wear and reducing replacement costs by 60%).
4.Machinery manufacturing:
Mold surface: Cold work mold sprayed with CrN coating (increased hardness to 80HRC, extended stamping times);
Hydraulic components: The inner wall of the oil cylinder is coated with nickel based alloy coating (replacing chrome plating), which is environmentally friendly and has better wear resistance.