The present invention is disclosed a microchannel array structure embedded in a silicon substrate and a fabrication method thereof. A blade reel assembly is disposed within the cutting box, the blade reel assembly including at least one blade, and being configured to rotate about an axle. The conditioned surface of the stem or shaft is disposed within the bonnet and moves the lubricating material relative to and in contact with the graphite packing ring during operation of the fluid valve. 2; subjecting the slurry to leaching treatment of the rare-earth elements under a temperature condition of room temperature to 160\xb0 C.