Development of braze repair technology for Ni-Al-Bronze (NAB) propellers

大量的大型船舶螺旋桨采用镍铝青铜（NAB）材料。在使用过程中，由于腐蚀，异物撞击和侵蚀/磨损而发生损坏。这些螺旋桨的更换成本在几到数万美元之间。因此，有修理/恢复这些昂贵部件的需求。多米尼斯工程公司目前正在使用熔焊工艺来修复NAB螺旋桨。这个过程是劳动密集型的，并且有很长的交货时间，因为每个缺陷都必须手工焊接。此外，焊接过程经常导致开裂和变形，这将需要反复焊接，矫直，重新俯仰和热处理。为了向客户提供大规模，快速周转的螺旋桨维修服务，多米尼斯工程公司正在寻求一种更有效的流程，使他们能够在批量过程中修复多个部件的所有缺陷。

A large number of propellers for large ships are made of Ni-Al-Bronze (NAB). During service, damages occur due to corrosion, foreign object impact and erosion/wear. Replacement cost of these propellers is in the range of several to tens of thousands of dollars. As such there is a demand to repair/restore these costly parts. Dominis Engineering is currently using a fusion welding process to repair NAB propellers. This process is labour intensive and has a long lead time as every defect has to be welded manually. Furthermore, the welding process often results in cracking and distortion which will require repeated welding, straightening, re-pitching and heat treatment. In order to provide a large scale, fast turnaround propeller repair service to its customers, Dominis Engineering is seeking a more efficient process which allows them to repair all defects on multiple parts in a batch process.