Plasma Sprayed Hydroxyapatite Coatings with Nano-hydroxyapatite Prepared by Ultrasonic Precipitation Process

Nano-particle hydroxyapatite （ HA ） was prepared with a novel ultrasonic precipitation process and the as-prepared nanopowder was used to produce hydroxyapatite （ HA ） coatings on titanium substrate via plasma spraying. The phase and the microstructare of the coating were characterized by X- ray diffraction （XRD） and scanning electron microscopy （SEM）. Results showed that spherical particles could be prepared by ultrasonic precipitation process; and a corresponding dense HA coating with molten surface and low-porosity cross-section structure was acquired. During the plasma spraying process, new phases of Ca3 （ PO4 ）2 and Ca2 P2O7 were generated. After heat-treating at 800℃ for 1 h, the contents of Ca3 （ PO4 ）2 and Ca2 P2O7 decreased while HA content increased. Tensile adhesion tests showed that the plasma sprayed coating prepared with the spherical nanoparticles exhibited high tensile bond strength.     

等离子喷涂工艺在曲轴修复中的应用

曲轴是车辆的重要零件,在设计和制造上很难达到与其它零件等寿命。曲轴损坏后,往往因配件短缺而影响车辆的正常使用。多年来,人们力求找到一种合适的修复方法来修复曲轴。下面,介绍几年来我们在这方面的一些探索。 一、曲轴的几种损坏形式 曲轴的损坏形式各有不同,现以我们在修复过程中接触到的情况加以归纳。 1.润滑系统发生故障 在车辆使用中,如油压不足、油路堵塞,造成轴与轴瓦的干摩、发热,直至烧瓦研轴。在进口汽车中,还往往由于代用机油标号不对,而发生此类情况。     

Y-Ba-Cu-O超导涂层的研制

用等离子喷涂工艺制备了 Y-Ba-Cu-O 高临界温度超导涂层,涂层的初始转变温度为101K、零电阻温度为86K。电阻率与磁化率的测量结果表明这种超导涂层具有与烧结超导块体相类似的性能,X 光衍射谱显示出涂层主要由 YBa_2Cu_3O_(?)单相化合物组成。     

气焊及切割工艺与设备

基于DSP的数字化控制逆变式空气等离子切割电源研究;逆变式等离子切割电源主电路的设计与仿真;切割用等离子弧的数值分析;高速走丝电火花线切割机床多次切割的实现