| Popis: |
The ability of a precision seed drill coulter to retain its cutting edge is an important factor determining drill performance. Abrasive soil particles cause wear and when using conventional metal coulters, frequent interruptions are necessary to check and adjust depth settings and to replace worn coulters. The effectiveness of alumina ceramic in reducing wear on other soil engaging components led to the investigation of its use as the cutting edge on precision seed drill coulters. Two designs of ceramic tipped coulter were used alongside conventional coulters to drill more than 1900 ha of sugar beet seed in a range of soil types and conditions. Profiles of the coulters were taken before and after use and the change in effective depth of their cutting edges was used as a measure of wear. Qualitative assessments of the change in cutting edge profile were also made. Mean wear ratios for each drill (wear of all conventional coulters/wear of all ceramic coulters) ranged from 1·5:1 to 6·4:1, with a mean of around 3:1. Reasons for the variability in relative performance are discussed. The reliability of both designs of coulter was very good. No failures of the adhesive bond joining the ceramic to the coulter body occurred, and only a limited amount of impact damage was noted. |
