Nd:YAG脉冲激光作用溶胶与纳米粉复合层制备复合纳米氧化锆涂层

利用Nd：YAG脉冲激光技术对在不锈钢上涂敷的氧化锆凝胶涂层进行加工处理，使凝胶涂层受热结晶并与不锈钢基体牢固结合制得纳米氧化锆涂层；同时利用自制的氧化锆纳米粉与氧化锆溶胶复合，激光作用后，激光辐照熔化粉末材料，同时溶胶结晶与粉末复合在不锈钢表面形成复合纳米氧化锆涂层。研究了激光对氧化锆凝胶及其与氧化锆纳米粉复合物的热作用，并描述了氧化锆涂层的结晶过程。     

新型溶胶-凝胶法制备Al2O3-ZrO2陶瓷涂层及其组织结构

采用新型溶胶-凝胶法,即在氧化铝溶胶中引入氧化锆陶瓷粉末制成复合浆料,在不锈钢表面制备了Al2O3-ZrO2陶瓷涂层,对涂层的显微组织、成分分布、相组成以及化学结构进行了研究.研究结果表明:该方法制备的涂层,厚度大大高于普通溶胶-凝胶法制备的涂层,涂层中形成了一种复杂的氧化铝网络结构,氧化锆颗粒被包覆在其中.最后,分析...     

等离子喷涂氧化锆涂层及激光重熔涂层的摩擦磨损性能

采用等离子喷涂制备了常规氧化锆涂层和纳米氧化锆涂层,并对制备的纳米氧化锆涂层进行了激光重熔处理,系统地研究了3种氧化锆涂层(常规、纳米和激光重熔涂层)在常温和高温下的摩擦磨损性能.结果表明,纳米氧化锆涂层耐磨性能明显优于常规氧化锆涂层,而激光重熔处理后的纳米氧化锆涂层在常温和高温下,都表现出最低的摩擦系数和最好的耐磨性能.这3种涂层的表面粗糙程度、涂层孔隙率和裂纹状况明显不同,从而表现出不同的摩擦磨损特性;说明纳米粉末等离子喷涂结合激光重熔技术是提高氧化锆涂层性能的有效方法.     

化学沉积法合成WC/Co粉体及其激光熔覆涂层的制备

采用化学沉积法合成了WC/Co复合粉体．通过激光熔覆的方法在2Cr13不锈钢基体上制备WC／Co复合涂层．并对复合粉体的成分、激光熔覆涂层的形貌、结构和性能进行研究、结果表明：复合粉体中Co的含量为17．23wt％，经过激光熔覆的复合涂层与基体之间达到了冶金结合．激光熔疆涂层可以分为三个区域：熔化区（合金层），结合区及基村热影响区．复合涂层的显微硬度达到1200HV0.1。     

氧化锆空心球粉体制备及其涂层性能研究进展

粉体是决定等离子喷涂热障涂层性能的基本因素,本文主要介绍了高性能等离子喷涂热障涂层用氧化锆空心球粉体的制备方法及其涂层性能的相关研究。等离子球化和喷雾干燥造粒是制备氧化锆空心球粉体的两种不同方法;氧化锆空心粉体在等离子喷涂过程中更易熔化,并且在熔化后形成空心液滴;空心液滴与基体碰撞铺展过程中存在的"反溅"使其铺展凝固时间更长,形成的扁平粒子直径小,厚度均匀,缺陷少;相对于其它类型粉体,采用氧化锆空心球粉体制备的热障涂层具有适中的孔隙率,低热导率和低模量,抗高温烧结,符合高性能热障涂层的性能要求。     

各种钢铁的焊接

低焊接裂纹敏感性高能量焊接用钢的应变时效行为;TCS不锈钢的焊接性能;Nd：YAG脉冲激光作用溶胶与纳米粉复合层制备复合纳米氧化错涂层;低功率YAG激光-MAG电弧复合焊接不锈钢;医疗器械用高氮不锈钢薄板激光焊接接头的组织与性能;     

各种钢铁的焊接

低焊接裂纹敏感性高能量焊接用钢的应变时效行为;TCS不锈钢的焊接性能;Nd：YAG脉冲激光作用溶胶与纳米粉复合层制备复合纳米氧化错涂层;低功率YAG激光-MAG电弧复合焊接不锈钢;医疗器械用高氮不锈钢薄板激光焊接接头的组织与性能;     

激光重熔纳米氧化锆热障涂层的抗热冲击性能

采用纳米氧化锆团聚粉末和等离子喷涂技术制备了纳米氧化锆涂层,试验研究了激光重熔工艺参数(激光比能量)对纳米氧化锆涂层抗热冲击性能的影响.结果表明,激光重熔工艺参数对重熔涂层的抗热冲击性能影响显著,采用合适的工艺参数(激光比能量),可以使重熔涂层获得最佳的抗热冲击性能.不同激光重熔工艺参数处理的涂层形成的组织结构不同,使得涂层的抗热冲击性能不同.合适的激光重熔工艺参数下涂层表现出高的抗热冲击性能,主要是因为重熔后的涂层组织结构有利于热应力的释放以及其相结构在高温冲击下具有良好的稳定性.     

等离子喷涂纳米氧化锆涂层摩擦性能研究

利用大气等离子喷涂技术,在不锈钢基体上用不同颗粒尺寸的纳米粉末制备了两种纳米氧化锆涂层S1(平均粒度较小颗粒的喷雾造粒粉末所得)和B1(平均粒度较大颗粒的喷雾造粒粉末所得).运用XRD、SEM、TEM、拉曼光谱和金相技术等分析手段对喷涂用的粉末原料和涂层的显微结构、物相组成进行了观察与确定;利用环-块摩擦试验在干摩擦条件下对涂层的摩擦磨损性能进行了测试.结果表明,两种氧化锆涂层的摩擦系数均随载荷增大而减小.在较低载荷(100 N)条件下,S1涂层与不锈钢的摩擦系数低于B1涂层与不锈钢的摩擦系数;而在较高(400 N)载荷下,两种氧化锆涂层的摩擦系数开始趋于一致.其原因在于:较低的载荷下两种涂层与不锈钢摩擦副的摩擦磨损机制不同,S1涂层的磨损属于粘着磨损,B1涂层的磨损属于磨粒磨损;而在较高载荷下,两种涂层的磨损机制趋于一致,均为粘着磨损.     

氧化锆粉体的制备及其在热障涂层中的应用

分别描述了纳米氧化锆粉体与空心球氧化锆粉体的制备工艺，分析了不同工艺影响氧化锆产物形态、结构、粒度等方面的因素，并将2种粉末制备的涂层分别与传统微结构涂层进行性能对比。在分析由不同氧化锆粉末制备而成的涂层性能时，除了工艺参数外，更多的是考虑初始氧化锆粉末对涂层性能所带来的影响。期待在未来的研究中，能够优化现有或者探索出更优异的制粉工艺，研究出性能更加优良的新型粉末，以期能够提高热障涂层的性能，满足高精尖领域在未来的使用需求。最后，针对不同制粉工艺及不同粉末制备涂层的发展方向进行了展望。     

Friction and wear properties of ultra-high molecular mass polyethylene reinforced with Al2O3 nano-particle

The ultra-high molecular mass polyethylene (UHMMPE) as an artificial joint acetabular material was filled with nano-powder of Al2O3 of various mass fractions. The effect of Al2O3 mass fraction on the hardness, wetting property and tribological properties of the Al2O3-UHMMPE composites under dry friction sliding against both stainless steel and Ti-6Al-4V alloy was investigated. The morphologies of the worn surfaces of composites were observed with optical microscope. The results show that, wetting property and wear resistance of the composites are improved by filling Al2O3, while the friction coefficient is decreased largely under dry friction as compared with that of the unfilled UHMMPE. This is attributed to the reinforcing function of the nano-powder of Al2O3 in the composites. The wear of UHMMPE is dominated by plowing, plastic deformation and fatigue wear; while the Al2O3-UHMMPE composites are characterized by the mild fatigue wear.     

太钢1Cr19Ni11Nb不锈钢无缝管的研制

针对1Cr19Ni11Nb电站锅炉用钢的使用环境特点,研究了1Cr19Ni11Nb作为耐热不锈钢使用的强化机理,分析了主要合金成分对材料组织和性能的影响,从而确定了合理的化学成分控制目标。通过采用现代先进自自“三步法”不锈钢冶炼工艺和“轧拔结合”的不锈钢制管工艺等技术,完成了该品种不锈钢管的试制。试制结果表明,太钢生产的1Cr19Ni11Nb不锈钢管坯和钢管能满足相关技术要求。目前该产品已进入批量生产阶段。     

2Cr19Ni9Mo不锈钢的强化

用光学显微镜、扫描电镜、透射电镜对２Ｃｒ１９Ｎｉ９Ｍｏ不锈钢强化机理进行了分析。结果表明，时效强化及形变强化的综合作用可使２Ｃｒ１９Ｎｉ９Ｍｏ不锈钢得到较高的强度。     

基于PSO-ELM的316L不锈钢细长管磁粒研磨内表面粗糙度预测模型

针对316L不锈钢细长管磁粒研磨加工过程中,最佳工艺参数难以选择,以及加工后对工件内表面粗糙度（Ra）的预测问题,将影响磁粒研磨316L不锈钢细长管内表面粗糙度的四个工艺参数作为输入值,内表面粗糙度作为输出值,构建粒子群（PSO）优化极限学习机（ELM）模型来预测316L不锈钢细长管内表面粗糙度,利用PSO对工艺参数进行全局寻优,获得最佳工艺参数组合,最后通过试验与预测结果进行对比。构建的PSO-ELM表面粗糙度预测模型拟合优度R2为0.984 8,绝对误差（MAE）为0.013 4,均方根误差（RMSE）为0.021 4。得到的最佳工艺参数组合为：主轴转速2 389.011r/min,进给速度3.167 mm/s,磨料粒径216.185μm,加工时间35.856 min,预测Ra为0.178μm。对工艺参数进行调整,试验得到的Ra为0.182μm,与预测值相比误差为2.24%。基于PSO-ELM方法构建316L不锈钢细长管内表面粗糙度预测模型,实现对工件内表面粗糙度的精确预测,应用粒子群方法得到最佳工艺参数组合,提高了磁粒研磨316L不锈钢细长管的加工效率。     

铁素体/奥氏体双相钢在旋转单相流体中腐蚀的数值模拟

引入现代流体力学方法，建立流体力学、传质过程、腐蚀电化学反应的综合数学模型，对双相钢在流动3．5％NaCl水溶液的腐蚀过程进行了数值模拟．探讨了近壁处流体力学参数对双相钢腐蚀过程的作用，模拟结果表明：双相钢的腐蚀主要受阳极过程控制，其中钝化膜中的传质过程是腐蚀的主要控制步骤．计算的腐蚀速度与实测值基本一致,验证双相钢的流体腐蚀机构．     

Al-SiC powder preparation for electronic packaging aluminum composites by plasma spray processing

Powders of pure aluminum (Al) with 55 and 75 vol.% SiC particles were ball milled in a conventional rotating ball mill with stainless steel and ZrO₂ balls for 1–10 h. The morphology and microstructure of the milled powders have been observed and analyzed by scanning electron microscopy (SEM) and energy dispersive x-ray (EDX). The milled powders were plasma sprayed onto a graphite substrate to obtain Al matrix composites with high SiC volume fraction. SiC particles in the milled powders existed in two forms; i.e., the combination of Al into composite powder and individual. Plastic Al particles were broken during ball milling, and fine Al particles can be coated onto the surface of SiC particles. Iron contamination in the milled powders occurred when stainless steel balls were used. The iron level can be effectively controlled by using ZrO₂ ball media. The milling efficiency by ZrO₂ balls is inferior to that by stainless steel balls. Longer milling time was required with ZrO₂ balls to achieve the same effect as obtained with stainless steel balls. SiC particles in the sprayed composites from the milled powders exhibited a reasonably uniform distribution and high volume fraction.     

城市输水用Q235B+304不锈钢复合管环焊焊接工艺

不锈钢复合管内侧为具有耐腐蚀性能的不锈钢,外侧为具有一定强度的碳钢,成为新一代环保型输水管。为了研究8 mm+2 mm厚城市输水用Q235B+304不锈钢复合钢管的环焊焊接工艺,试验选用合理的焊接材料及坡口形式等,获得了复合板与复合板、复合板与碳钢板的焊接接头。通过拉伸、冲击、弯曲试验评价两种焊接接头的力学性能;通过检测接头不锈钢焊道化学成分,评估复合管焊接接头内侧不锈钢焊道的耐晶间腐蚀性能。结果表明,所采用的焊接工艺获得的接头力学性能满足技术要求且富余量较大,复合管接头不锈钢焊缝获得了A+(5%~10%)δ组织,耐晶间腐蚀性能优异。     

不锈钢管力学性能的拉伸试验

通过单向拉伸试验获得7种规格的21-6-9不锈钢管及3种规格的321不锈钢管的基本力学性能参数,21-6-9不锈钢管强度高、塑性差,其力学性能特征不利于拉深、弯曲等塑性成形;与21-6-9不锈钢管相比,321不锈钢管强度低、塑性好。分别通过弧形试样拉伸试验和管段试样拉伸试验,获取了Φ1.25mm×0.02mm厚的规格21-6-9不锈钢管的力学性能参数,发现由管段试样获得的延伸率大于弧形试样获得的延伸率,其屈服强度及抗拉强度略小于弧形试样获得的屈服强度及抗拉强度。由于弧形试样拉伸过程中,试样受到的并不是单向应力状态,因此管段试样获得的结果更准确。     

Microstructure and antibacterial property of stainless steel implanted by Cu ions

Copper ions were implanted into AISI 304 austenitic stainless steel by metal vapor vacuum are (MEVVA) with 60 - 100 keV energy and a dose range (0.2 - 5.0) × 1017 cm-2. Then Cu-implanted stainless steel was treated by a special antibacterial treatment. Antibacterial rates of Cu-implanted stainless steel, Cu-implanted stainless steel with special antibacterial treatment and un-implanted stainless steel were obtained by agar plate method. Phase composition in the implanted layer was analyzed by glancing X-ray diffraction (GXRD). Microstructure of antibacterial stainless steel was observed with transmission electron microscopy (TEM), and changes of the bacterium appearance after 24 h antibacterial action on the surface of un-implanted and Cu-implanted stainless steel with antibacterial treatment were observed with bio-TEM respectively. The results show that stainless steel obtains antibacterial property against E. coli when the Cu ions dose approaches to the saturated one. A suitable amount of Cu-rich phase uniformly disperses on the surface of Cu-implanted stainless steel that is treated by the special antibacterial treatment. The Cu-rich phase naked on the surface has a function of damage to pericellular membrane and cell wall,the pericellular membrane is thickened and the karyon degraded, and finally, bacteria die. Cu-rich phase naked on the surface endows stainless steel with best antibacterial property.     

Wettability,microstructure and properties of 6061 aluminum alloy/304 stainless steel butt joint achieved by laser-metal inert-gas hybrid welding-brazing

Laser-metal inert-gas (MIG) hybrid welding-brazing was applied to the butt joint of 6061-T6 aluminum alloy and 304 stainless steel. The microstructure and mechanical properties of the joint were studied. An excellent joint-section shape was achieved from good wettability on both sides of the stainless steel. Scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffractometry indicated an intermetallic compound (IMC) layer at the 6061-T6/304 interface. The IMC thickness was controlled to be ～2 μm, which was attributed to the advantage of the laser-MIG hybrid method. Fe₃Al dominated in the IMC layer at the interface between the stainless steel and the back reinforcement. The IMC layer in the remaining regions consisted mainly of Fe₄Al₁₃. A thinner IMC layer and better wettability on both sides of the stainless steel were obtained, because of the optimized energy distribution from a combination of a laser beam with a MIG arc. The average tensile strength of the joint with reinforcement using laser-MIG hybrid process was improved to be 174 MPa (60% of the 6061-T6 tensile strength), which was significantly higher than that of the joint by traditional MIG process.