论文部分内容阅读
利用激光烧结快速成型技术可以烧结覆膜陶瓷材料，形成铸造用型腔壳体并直接应用于铸造，制作金属零件。由于在快速原型制造领域所使用的激光器功率普遍较低，因此，无法实现真正意义上材料的直接烧结。目前所能实现的是覆膜陶瓷的间接烧结，即利用激光融凝陶瓷表面涂覆的有机物薄膜，使陶瓷粉末粘结成一个原型壳体。由此形成的壳体原型强度较低，不能直接用于铸造。因此，二次烧结作为一种后处理工艺用于提高壳体强度．与烧结工艺参数对原型壳体强度的影响变得同等重要。通过试验分析，在烧结工艺参数中，扫描间隔和扫描速度是影响原型壳体强度的主要因素，其直接影响烧结原型第一强度的变化。二次烧结后处理可以大幅度提高壳体的二次强度，满足铸造对壳体的强度要求。最后以整体叶轮的快速制造为例，验证了上述结论。
The use of laser sintering rapid prototyping technology can be sintered coated ceramic materials, forming a casting cavity shell and applied directly to casting, making metal parts. Due to the generally low laser power used in rapid prototyping, direct sintering of the material is not possible in the true sense of the word. At present, what can be achieved is the indirect sintering of the coated ceramic, that is, the organic thin film coated on the surface of the laser fused ceramic is used to bond the ceramic powder into a prototype shell. The resulting prototype shell has low strength and can not be used directly for casting. Therefore, the secondary sintering as a post-treatment process used to improve the shell strength. The effect of the sintering process parameters on the strength of the prototype shell becomes equally important. Through experimental analysis, in the sintering process parameters, scanning interval and scanning speed are the main factors affecting the strength of the prototype shell, which directly affects the change of the first intensity of the sintered prototype. Post-sintering treatment can greatly improve the secondary strength of the shell to meet the casting of the shell of the strength requirements. Finally, taking the rapid manufacture of the whole impeller as an example, the above conclusion is verified.