Laboratory studies of cutting elements wear-out resistance of drill bits, reinforced by polycrystalline diamond inserts

Author(s):  
A.A. Tretyak ◽  
◽  
Yu.F. Litkevich ◽  
А.N. Grossu ◽  
K.A. Borisov ◽  
...  
1985 ◽  
Vol 107 (4) ◽  
pp. 534-542 ◽  
Author(s):  
C. L. Hough ◽  
B. Das

The wear characteristics of polycrystalline diamond compact (PDC) drill bits were investigated in the context of drilling small holes in a hard abrasive medium. An efficient method for measuring wear of the PDC drill bits was developed. The wear test results were grouped or categorized in terms of rotary speed, feed and wear or failure characteristics. Contrary to the three classical wear phases (break-in, uniform wear and rapid breakdown) of the single material cutters, four distinctive wear phases were formed for the PDC cutters: I–break-in, II–diamond wear, III–carbide wear, and IV–rapid breakdown. The characteristics of the wear phases were identified and some suggestions were made to alleviate the wear problem.


2009 ◽  
Vol 404 ◽  
pp. 157-163
Author(s):  
Pei Lum Tso ◽  
Cheng Huan Chen

Sintered polycrystalline diamond (PCD) compacts are normally used for cutting tools, drill bits and wire dies. A novel application of PCD has been developed to use its entire surface carved to create different patterns which are triangle or square shape loaded with leveled millers that can shave brittle materials in ductile mode. Due to numerous cutting edges formed on the same level of PCD tools, which can be used to thin the wafer surface to achieve both flatness and smoothness of the industrial requirements. SEM has been used to observe the surface and subsurface of the thinned wafer surface. The critical depth of cut between ductile and brittle cutting mode is close to 2 µm in this thinning operation. The damaged layers of machined surface have been observed and studied in this paper.


Author(s):  
M. Salahshoor ◽  
Y. B. Guo

Metallic degradable biomaterials have attracted a huge attention lately for orthopedic fixation applications. Binary magnesium and calcium (Mg-Ca) alloys have emerged as a promising choice in terms of biocompatibility to avoid stress shielding and provide sufficient mechanical strength. In this paper, efficient and ecologic machining of a lab-made Mg-Ca alloy with 0.8 wt% calcium, cutting speeds of up to 47 m/s, and without coolant are investigated. Polycrystalline diamond inserts are applied and the possibilities of flank built-up formation, chip ignition, and tool wear are sought during the cutting experiments with the aid of a developed on-line, optical monitoring system. Chip morphology characteristics produced by different combinations of cutting parameters, i.e. cutting speed, feed, and depth of cut are studied.


2017 ◽  
Vol 47 (9) ◽  
pp. 594-598 ◽  
Author(s):  
R. Yu. Kuftyrev ◽  
N. I. Polushin ◽  
O. S. Kotel’nikova ◽  
A. I. Laptev ◽  
M. N. Sorokin

1986 ◽  
Vol 108 (4) ◽  
pp. 310-314
Author(s):  
C. L. Hough ◽  
B. Das ◽  
T. G. Rozgonyi

Mathematical models for bit life of polycrystalline diamond compact (PDC) drill bits were developed for drilling small holes in hard abrasive media. Based on the wear-out criterion of an average 0.060 in. (1.5 mm) flank wear land, bit life equations were formulated in three forms: bit life versus rotary speed and feed rate, bit life versus rotary speed and penetration rate, and wear rate versus cutting speed and cutter engagement area. The traditional linear-logarithmic model proved inadequate to describe bit life, whereas the quadratic-logarithmic model provided the best bit life prediction equation. Consequently, it would be possible to predict the optimum economical drilling conditions more accurately by employing a quadratic-logarithmic based bit life equation. The equation demonstrated the ability to predict the bit life precisely under different modes of wear.


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