Choi Dong-ik:, Park Byong-joon, Oh Jeang Ook.
ILJIN Diamond Co., Ltd., Eumsung-Kun, Chucheongbuk-Do, 369-824, Korea
Abstract A study is performed on a newly developed Polycrystalline Diamond Cutter(PDC)with improved impact resistance. Impact resistance of PDC is dependent on diamond grain size, binder content and property of the substrate. A crack might initiate in the substrate by the impact transferred from the diamond layer if substrate is not tough enough to absorb it. This failure is caused by the residual stress at the interface resulting from the difference of thermal expansion coefficient between diamond and substrate.
This kind of failure could be reduced to some extent by optimizing the grain size of WC and content of Co in the substrate. PDC with much improved impact resistance is produced by also optimizing the diamond size and the content of binder phase in the layer.
Drop-test with different conditions of energy and speed are carried out on the newly developed PDC and wear resistance test is done and the result is compared with that of previous PDC.
It is found that the newly developed PDC shows 40% better impact resistance than previous PDC.