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Effects of plasma spraying process on microstructure and mechanical properties of Cr_(2)AlC/410 composite coatings

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High-Speed Railway 2024年第2期2卷 110-115页

作者： Yihu Ma Chaosheng Ma Guozheng Ma Wenbo Yu Center of Materials Science and engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China National Key Lab for Remanufacturing Army Academy of Armored ForcesBeijing 100072China

To investigate the influences of Cr_(2)AlC mass fraction and supersonic plasma spraying process on the microstructure and mechanical properties of Cr_(2)AlC reinforced 410 stainless steel composite coatings,the coatings containing different mass fractions of Cr_(2)AlC were prepared and *** composite coating exhibited low porosity and high adhesion *** addition of Cr_(2)AlC significantly enhanced the hardness of the composite coatings through particle ***,when the mass fraction of Cr_(2)AlC was 20%,the aggregation of Cr_(2)AlC resulted in a strong decrease in the coating preparation efficiency,as well as a decline in adhesion *** the supersonic plasma spraying process,the Ar flow rate mainly influenced the flight velocity of the particles,while the H_(2) flow rate and the current mainly affected the temperature of the plasma ***,all of them influenced the melting degree of particles and the quality of the *** lowest porosity and the highest hardness and adhesion strength could be obtained when the Ar flow rate is 125 L/min,the H_(2) flow rate is 25 L/min,and the current is 385 A.

关键词： MAX phase Plasma spray Parameter Coating

Ultra wear resistant TiC-Fe coating prepared by high efficient and economic plasma cladding method

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China Welding 2024年第1期33卷 20-26页

作者：黄大牛仝永刚华熳煜牟泓霖柳建蔡志海胡永乐 College of Automotive and Mechanical engineering Changsha University of Science and TechnologyChangsha 410114China National engineering Research Center for Mechanical Product Remanufacturing Army Academy of Armored ForcesBeijing 100072China

The key components of engineering machinery frequently failed due to working in the high load and high wear operating *** the performance of the Fe-based alloy coatings typically employed need to be improved for fulfilling the service ***,a TiC strengthened Fe-based alloy cladding layer,named TiC-Fe coating,was designed and prepared by plasma cladding *** frictional wear performance of coating under various loads was *** wear morphology of the coating was observed,and its wear mechanism was *** results indicated that the TiC-Fe coating was well formed and metallurgically bonded to the Q345C *** microstructure mainly consisted of Fe-Cr solid solution,α-Fe phase,(Fe,Cr)_(7)C_(3) phase and TiC *** coating exhibited an average microhardness of 980 HV0.2,which was about 5.4 times that of the Q345C *** wear mass loss of the TiC-Fe coatings was much smaller than that of the Q345C substrate,which indicated that the wear resistance of the Q345C coating was superior to the substrate,and the wear mechanism of the coating was mainly attributed to the abrasive wear.

关键词： plasma cladding TiC microstructure wear resistance

水下激光填丝直接能量沉积法制备贫双相不锈钢2101的组织和织构演变

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Journal of Central South University 2024年第1期31卷 72-83页

作者：蔡志海王凯朱加雷焦向东杜娴王海斗 National engineering Research Center for Remanufacturing Army Academy of Armored ForcesBeijing 100072China CISRI HIPEX Technology Co. Ltd.Beijing 100081China Beijing Institute of Petrochemical Technology Beijing 100029China

贫双相不锈钢2101(LDX 2101)是一种可以替代304奥氏体不锈钢的低镍不锈钢材料,以良好的经济性、力学性能和耐腐蚀性而被广泛研究,在核电工程中具有广泛的应用前景。针对核电工程水下维修技术背景,利用光学显微镜和电子背散射衍射等方法... 详细信息

贫双相不锈钢2101(LDX 2101)是一种可以替代304奥氏体不锈钢的低镍不锈钢材料,以良好的经济性、力学性能和耐腐蚀性而被广泛研究,在核电工程中具有广泛的应用前景。针对核电工程水下维修技术背景,利用光学显微镜和电子背散射衍射等方法,研究了水下环境激光填丝直接能量沉积工艺制备的贫双相不锈钢2101的微观组织和织构演变。结果表明,水下环境对熔池的快速冷却作用抑制了铁素体向奥氏体的转变进程。由于铁素体的表面能最低,大多数铁素体是沿着密排堆积的(111)α和(110)α平面沉积的,沉积结构呈现典型的立方结构和高斯结构。尽管奥氏体的织构不如穿过沉积层的铁素体的织构强,但结果表明,奥氏体相相对于铁素体相形成了更紧密的Kurdjumov-Sachs取向关系。激光填丝直接能量沉积工艺的循环再加热效应不仅改变了贫双相不锈钢2101的组织和织构,还影响了晶粒尺寸和特殊晶界的比例。提高沉积结构中∑3晶界的含量和分布均匀性,有利于增强沉积层的耐蚀性。

关键词：贫双相不锈钢激光填丝直接能量沉积织构演化耐腐蚀性

High Velocity Electric Arc Sprayed Fe-Al-Nb-B Composite Coating and Its Wear Behavior

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Acta Metallurgica Sinica(English Letters) 2013年第3期26卷 313-320页

作者： Yongxiong CHEN Xiubing LIANG Jinyuan BAI Binshi XU National engineering Research Center for Mechanical Product Remanufacturing Academy of Armored Forces Engineering National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering

A type of Fe-Al-Nb-B cored wire was designed and the coating was prepared using a robot-based electric wire arc spraying process. The Fe-Al binary cored wire and coating were also prepared as comparison. The phase composition and structure of the coatings were investigated using X-ray diffraction （XRD）, scanning electron microscopy （SEM） coupled with energy dispersive X-ray spectroscopy （EDS） and transmission electron microscopy （TEM）. The coating tribological properties were evaluated with the micromotion wear tester under different conditions. The results show that, although typical lamellar structure was performed for both the arc sprayed Fe-Al-Nb-B coating and Fe-Al coating, the structure composition, mechanical and wear properties of the former are quite different from those of latter. The Fe-Al-Nb-B coating is a typical composite coating, which is distributed inhomogeneously with α-Fe crystalline, FeAl and Fe3Al intermetallics, amorphous and nanocrystallines as well as locally existed oxide phases. As a result, the mircrohardness and wear resistance of the Fe-Al-Nb-B composite coating increased significantly. Finally the mechanism of the coating wear resistant behavior was discussed based on the experimental results such as friction coefficient, two dimensional and three dimensional worn surface profiles.

关键词： Fe-Al-Nb-B coating Structure High velocity electric arc spraying Wear resistance

Structure and sliding wear behavior of 321 stainless steel/Al composite coating deposited by high velocity arc spraying technique

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中国有色金属学会会刊：英文版 2008年第3期18卷 603-609页

作者：陈永雄徐滨士刘燕梁秀兵许一 National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering

A typical 321 stainless steel/aluminum composite coating (321/Al coating) was prepared by high velocity arc spraying technique (HVAS) with 321 stainless steel wire as the anode and aluminum wire as the cathode. The traditional 321 stainless steel coating was also prepared for comparison. Tribological properties of the coatings were evaluated with the ring-block wear tester under different conditions. The structure and worn surface of the coatings were analyzed by scanning electron microscopy(SEM), X-ray diffractometry(XRD) and energy dispersion spectroscopy(EDS). The results show that, except for aluminum phase addition in the 321/Al coating, no other phases are created compared with the 321 coating. However, due to the addition of aluminum, the 321/Al coating forms a type of "ductile/hard phases inter-deposited" structure and performs quite different tribological behavior. Under the dry sliding condition, the anti-wear property of 321/Al coating is about 42% lower than that of 321 coating. But under the oil lubricated conditions with or without 32 h oil-dipping pretreatment, the anti-wear property of 321/Al coating is about 9% and 5% higher than that of 321 coating, respectively. The anti-wear mechanism of the composite coating is mainly relevant to the decrease of oxide impurities and the strengthening action resulted from the "ductile/hard phases inter-deposited" coating structure.

关键词： HVAS 合成材料奥氏体不锈钢滑动磨损

Heat transfer analysis of atomized droplets during high velocity arc spraying

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 103-105页

作者： ZHU Zi-xin LIU Yan CHEN Yong-xiong XU Bin-shi ZHANG Wei National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China National Key Laboratory for RemanufacturingAcademy of Armored Forces Engineering Beijing 100072 China National Key Laboratory for RemanufacturingAcademy of Armored Forces Engineering Beijing 100072 China National Key Laboratory for RemanufacturingAcademy of Armored Forces Engineering Beijing 100072 China National Key Laboratory for RemanufacturingAcademy of Armored Forces Engineering Beijing 100072 China

The heat transfer problem of the atomized droplets during high velocity arc spraying (HVAS) was modeled and solved by a numerical method using a Fe-Al alloy, and the influences of several important process parameters on the heat transfer behaviors of the atomized droplets were analyzed. The results show that the initial cooling rates of different size droplets range from 105 to 107 K/s, thus producing the coating microstructure with the features of rapid solidification. The droplet size, atomization gas pressure and droplet superheat have great influences on the heat transfer behavior of the droplet. The droplet temperature and cooling rate are much sensitive to the droplet sizes, but insensitive to the atomization gas pressure and droplet superheat. It can be predicted that the properties of HVAS coatings will be improved by decreasing droplet size as well as increasing atomization gas pressure and droplet superheat in certain extents.

关键词： high velocity arc spraying atomized droplet heat transfer numerical simulation

Configuration optimization of high velocity arc spraying gun

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 100-102页

作者： CHEN Yong-xiong ZHU Zi-xin LIU Yan XU Bin-shi National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China

In order to improve the in-flight characteristics of the atomizing droplets during high velocity wire arc spraying (HVAS), some changes have been operated on the original design of the HVAS gun configuration. A comparative study was carried out to investigate the microstructure and properties of the coatings produced by the original design spraying gun and the modified one, using 3Cr13 wires of 3 mm in diameter. The characteristics of their jets were examined during spraying. The results indicate that, the included angle between the two wires and the distance from the nozzle to the meeting point of the two vires may have a strong influence on the characteristics of the in-flight droplets and then the coatings. The jet divergence is found to be lower than that of the original one (about 12° against 25°). By modified gun, the adhesion strength, the microhardness and porosity of the coating deposited by modified gun are increased by 39% and 9% respectively. And the porosity of the coatings is decreased by 57%.

关键词： high velocity arc spraying gun configuration optimization coating

Investigation of Stress Corrosion Cracking Initiation of 7A52 Aluminum Alloy

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Journal of Wuhan University of Technology(Materials Science) 2012年第4期27卷 648-651页

作者：李奇 Department of Equipment Remanufacture engineering Academy of Armored Forces Engineering

The stress corrosion cracking（SCC） behaviour of 7A52 aluminum alloy in air and in 3.5% NaCl solution was researched by slow strain rate test（SSRT） and SEM-EDS. The SCC susceptibility was estimated with the loss of the reduction in area. The experimental results indicate that the SCC susceptibility of 7A52 aluminum alloy in 3.5% chloride solution is the highest at strain rate of 1×10-6 s-1. The lowest one is under the condition of 1×10-5 s-1. Stress concentration and anode dissolving around Al-Fe-Mn intermetallics initiate micropores which will result in microcracks. The existence of intermetallics in the microstructure may play an important role in understanding the SCC initiation mechanisms of 7A52 aluminum alloy.

关键词： 7A52 aluminum alloy stress corrosion cracking stress corrosion cracking susceptibility intermetallics

Fatigue damage evaluation by metal magnetic memory testing

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Journal of Central South University 2014年第1期21卷 65-70页

作者：王慧鹏董丽虹董世运徐滨士 National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering

Tension-compression fatigue test was performed on 0.45% C steel *** and tangential components of magnetic memory testing signals,Hp(y) and Hp(x) signals,with their characteristics,K of Hp(y) and Hp(x)M of Hp(x),throughout the fatigue process were presented and *** peaks of Hp(y) and peak of Hp(x) reversed after loading; Hp(y) curves rotated clockwise and Hp(x) curves elevated significantly with the increase of fatigue cycle number at the first a few fatigue cycles,both Hp(y) and Hp(x) curves were stable after that,the amplitude of abnormal peaks of Hp(y) and peak value of Hp(x) increased more quickly after fatigue crack *** peaks of Hp(y) and peak of Hp(x) at the notch reversed again after *** characteristics were found to exhibit consistent tendency in the whole fatigue life and behave differently in different stages of *** initial and crack developing stages,the characteristics increased significantly due to dislocations increase and crack propagation,*** stable stage,the characteristics remained constant as a result of dislocation blocking,K value ranged from 20 to 30 A/(m·mm)-1,and Hp(x)M ranged from 270 to 300 A/m under the test parameters in this *** failure,both abnormal peaks of Hp(y) and peak of Hp(x) reversed,K value was 133 A/(m·mm)-1 and Hp(x)M was-640 A/*** results indicate that the characteristics of Hp(y) and Hp(x) signals were related to the accumulation of fatigue,so it is feasible and applicable to monitor fatigue damage of ferromagnetic components using metal magnetic memory testing(MMMT).

关键词： metal magnetic memory testing MMMT signal tension-compression fatigue test feature extraction