Materials Synthesis and Processing: A Novel Technique of Net-Form Materials Synthesis

提出了一种新型的网状材料合成方法，并成功地完成了初步的验证实验。该方法使用高度均匀的熔融金属液滴流，这些液滴在受控环境中沉积到衬底上，例如真空或选定气体的更高压力。控制液滴沉积速度，以便快速凝固，从而获得具有小颗粒尺寸和高结构完整性的网状材料。通过使用新的液滴流生成技术，液滴以非常小的角度和速度分散定向到衬底上，从而使合成微小的详细部件成为可能。由于液滴的大小相同(通常直径为30-150微米)，并且以相同的速度移动，因此最终产品中没有预凝固液滴会产生比通常使用其他相关技术获得的更均匀、质量更高的部件。由于凝固速度决定了净成形部分的结构完整性，因此液滴沉积速度、速度和大小在研究中将有所不同。将用光学和电子显微镜检查网状成形零件的均匀性和颗粒结构，并通过对成形零件进行压缩和拉伸试验来研究其机械特性。将建议过程简化为实践可能允许直接从基于计算机的描述快速制造部件。由此产生的零件也可以生产出具有新颖的、高强度的结构。

A novel method of net-form materials synthesis has been conceived and initial verification experiments have been successfully completed. The method uses streams of highly uniform droplets of molten metal which are deposited onto a substrate in a controlled environment such as a vacuum or higher pressures of selected gases. The droplet deposition rate is controlled such that rapid solidification occurs leading to a net-formed material with small grain size and high structural integrity. By using novel droplet stream generation techniques the droplets are directed onto the substrate with very small angular and speed dispersions thereby making possible the synthesis of small detailed parts. Since the droplets are the same size (typically 30-150 microns in diameter) and travel at the same speed, the absence of pre-solidification droplets in the final product leads to a more homogeneous, and thus higher quality part than is normally achieved with other related techniques. Since the solidification rate determines the structural integrity of the net-formed part, the droplet deposition rate, speeds, and sizes are parameters which will be varied in the study. The homogeneity and grain structure of the net-formed parts will be examined both optically and with the use of an electron microscope, and their mechanical characteristics will be studied by subjecting formed parts to tests in both compression and tension. The reduction of the proposal process to practice may allow the rapid fabrication of parts directly from computer-based descriptions. The resulting parts may also be produced with novel, high strength structure.