STUDY ON THE CHARACTERISTICS OF TILLER BLADE SHAPES BY SPRAY-WELDING HARDENING

摘要

These studies were aimed at the validation test which analyzes the mathematical models for the plowing force and trajectory curves of both tiller blades and cultivation blades of a rotary. These two blades are widely used in Taiwan. The results showed that the blades need uniform resistance to soil without intertwisting to obtain good plow efficacy. The theoretical and calculated cutting angles are 85.88° and 84.28°, and the edge-curve angles are 59.70° and 58.31° for the blades. The present data confirmed that the tiller blades developed by local companies are suitable for the plowing environment in Taiwan. In order to reduce the cost from frequent change of the blade due to wear and tear, the Nickel-Base alloy powder welding technique was applied to increase the surface hardening of tiller blades. In the Schwingung Reibung Verschleiss (SRV) testing mechanism experiment, the duration of attrition for the coating and the abrasive parameters has shown that SUP-HT specimens performed better than the SUP-H specimens. The SUP-HT also has a better anti-oxidized function with a hardness parameter (HRc) of 58-60. The adherence after compression has graded as A-class under Scanning Electronic Microscopy (SEM). It can be proved that the coating surface of the tiller blades treated with alloy powder welding would increase uniformity, precision and stability when using the alloy powder spray-welding mechanism developed in this study. As it is applied to the real situation, the natural soil can free from the contamination of iron particle coming off the blades up to 618,000kg. Meanwhile, a labor cost of 7.5 hr and equipment cost 4,620 NT can be saved per set of tractor, minimizing the cost of production.