为了确定最佳的金刚石薄膜涂层刀具，对不同合成条件下生产的实验刀具和基体刀具材料进行了一系列评估试验。通过这些测试，氮化硅陶瓷刀具被认为是金刚石涂层刀具的最佳基材之一。在加工低硅铝合金和玻璃钢时，金刚石涂层氮化硅刀具的磨损与烧结金刚石刀具几乎相同。特别是对于低硅含量的铝合金，它能够以高于1500 M/MIN的切割速度进行切割。

TO DETERMINE THE OPTIMUM TOOL COATED WITH DIAMOND FILM, A SERIES OF EVALUATION TESTS WERE PERFORMED ON EXPERIMENTAL TOOLS PRODUCED BY VARIOUS SYNTHESIZING CONDITIONS AND SUBSTRATE TOOL MATERIALS. FROM THESE TESTS, SILICON NITRIDE CERAMIC TOOL WAS FOUND TO BE ONE OF THE BEST SUBSTRATE MATERIALS FOR DIAMOND COATED TOOL. IN MACHINING OF LOW SI CONTENT ALUMINUM ALLOY AND FRP, THE DIAMOND COATED SILICON NITRIDE TOOL SHOWED ALMOST THE SAME TOOL WEAR AS THAT OF SINTERED DIAMOND TOOL. IN PARTICULAR, FOR LOW SI CONTENT ALUMINUM ALLOY, IT WAS ABLE TO CUT AT A CUTTING SPEED ABOVE 1500 M/MIN.