ABSTRACT

An innovative friction stir processing variant, named Upward Friction Stir Processing (UFSP), for producing customized materials with multifunctional particles is presented. In the UFSP, an upward flow is used to disperse these functional particles in a metallic matrix, in opposition to the widely used downward flow. As a proof of concept, SiC particles were introduced and dispersed into an aluminum alloy AA7075-T651 matrix to study different process parameters and to validate this novel material processing technology. Six different small-sized ingots were produced and compared to the conventional FSP technology. The microstructural evolution is studied by means of light microscopy, eddy current testing, microhardness mapping and advanced characterization techniques, such as high-energy synchrotron X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and electron backscatter diffraction. The number of passes was seen to greatly impact the particle distribution. Additionally, UFSP promotes a more uniform particle distribution over a larger processed area, when the lateral tool offset progress along the retreating side.

摘要

提出了一种创新的摩擦搅拌加工变体，称为向上摩擦搅拌加工 (UFSP)，用于生产具有多功能颗粒的定制材料。在 UFSP 中，与广泛使用的向下流动相反，向上流动用于将这些功能颗粒分散在金属基体中。作为概念验证，将 SiC 颗粒引入并分散到铝合金 AA7075-T651 基体中，以研究不同的工艺参数并验证这种新型材料加工技术。生产了六种不同的小型铸锭，并与传统的 FSP 技术进行了比较。通过光学显微镜、涡流测试、显微硬度映射和先进的表征技术（如高能同步辐射 X 射线衍射、扫描电子显微镜、能量色散 X 射线光谱和电子背散射衍射。可以看出通过次数对颗粒分布有很大影响。此外，当横向刀具偏移沿后退侧进行时，UFSP 促进了更大加工区域上更均匀的颗粒分布。