The Research Of Multi-layer Diamond Brazing Thin-wall Drills Of Small Diameter With The Effect Of Efficient Chip Removal And Heat Dissipation

Basic and experimental research about diamond thin-walled drills is carried out on the basic ofsummarizing the advantage and defect of brazing diamond tools, including substrate structureoptimization of multi-layer brazed effect, fabrication process and the technology of efficient chipremoval and heat dissipation. The multi-layer diamond brazed result is realized and the problem ofchip removal and heat dissipation is solved. The drills’ working life is improved observably during thedrilling test.The main contents completed in this paper are as follows:(1) These6mm-outside-diameter diamond core drills are made by using the creative fabricationprocess through the technology of high-temperature vacuum brazing. The effect of multi-layer isobserved with scanning electron microscope (SEM) in all three kinds of diamond drills with differentsteel substrate structures, and these drills have more wear stages and longer working life than thenormal drills.(2) Establish the orthogonal experiment with working life as the test index and investigate theinfluence on the test index of every experimental factor. Draw a conclusion that the key factor is thewidth of the slots to realize the multi-layer diamond brazed effect, and the dimensions of steelsubstrate structure are optimized further.(3) Optimize substrates’ ektexine structure in order to remove chip efficiently, and select theproper organic heat transfer material (paraffin wax). Efficient chip removal and heat dissipation isrealized during drilling the super-hard engineering ceramics without cooling fluid. Meanwhiletheoretical analysis is carried on to clarify the cause of the phenomenon.(4) Excellent drilling performance is proved during the compare test with normal brazeddiamond drills, sintered diamond bits and electroplated diamond bits. In addition, some key points forusage are summarized during the practical application.