Ni radical, Ni
- source:WEDEMEYER CNC Machining
49kgfm/cm2) ; Observation microscope is microscope of JGX-1 all-purpose tool and lens of report of scanning of ISM-6400 SCANNING MICROSCOPE (SEM) . Cutting condition is: Feed 0.
08mm/r, cutting speed 25m/min, cutting deepness 0.
5mm, ° of G0=4 of angle of cutting tool geometry, a0=8 ° , kr=45 ° ; B=78 ° . The chemical composition of bit coating material and heat treatment standard see a table 1. Ni of composition of chemistry of the chemical composition that expresses material of coating of 1 razor blade and coating of hardness of HV of temperature of heat treatment of ply of coating of type of coating of heat treatment standard base 1h+400 of 14µm200 ℃ × ℃ × 1h7255.
7%NiNi base 1h7306 of × of 1h+400 ℃ of 14µm200 ℃ × .
1%NiNi-W base 1h8628 of × of 1h+400 ℃ of 12µm200 ℃ × .
8%WNi-W base 1h9254 of × of 1h+400 ℃ of 11µm200 ℃ × .
1%WNi-W base 1h9757 of × of 1h+400 ℃ of 13µm200 ℃ × .
1%WNi-W base 1h10255 of × of 1h+400 ℃ of 15µm200 ℃ × .
4%W experiment content and methodological test content: Observation not coating, Ni radical is mixed razor blade of Ni-W radical coating wears away mediumly in turning treatment configuration and wear away the rule. Try proved recipe way: Use the circle outside test specimen of straight-cut law turning, maintain back penetration of a cutting tool to measure Ap=0.
5mm, feed F=0.
5mm, change respectively machine with different cutting tool, record cutting time with stopwatch, use microscope observation bit hind knife face wear extent VB. In wear away in comparative experiment, the VBmax of the biggest wear extent of area of B of face of the knife after measuring 3 kinds of razor blade after passing identical cutting time respectively, compare its to wear away rate. Cutting tool wears away after the experiment, be opposite respectively with scanning report lens of 3 kinds of razor blade before, hind knife face wears away form appearance has observation (key observation is right of the part of point of a knife with workpiece surface surface roughness and treatment precision the largest influence grind, ) of damaged form appearance, fight damaged characteristic with what this decides bit. 3 tests result and analytic graph are shown 1 times for not coating is mixed the comparative wear curve of razor blade of coating of Ni radical, Ni-W radical. By the graph 1 visible, when face of the knife after bit VBmax of the biggest wear extent achieves a regulation to grind blunt standard (VB=0.
When 30mm) , ni radical is mixed place of razor blade of Ni-W radical coating is compared with time not coating razor blade increases 60 seconds above, the cutting performance that indicates coating razor blade is compared not coating razor blade has definite improvement. In cutting process, use not of the workpiece when coating razor blade cut bits to present violet black, show cutting temperature is higher; And use Ni radical and Ni-W base bits is cut to all be shown when coating razor blade is machined brown, make clear cutting temperature under not coating razor blade. Analyse Ni radical and Ni-W base the mechanism that function of cutting of coating razor blade improves, can think coating matrix is medium in great quantities the existence of solid solution of Ni radical alloy is the main reason that makes obdurability of coating composite material rises greatly. The process is burned in frit of coating composite material in, a large number of alloying element (wait like Fe, Cr, W, Ti, Si) diffuse each other, major element dissolve enters Ni in, fashion solid solution of Ni radical alloy, make matrix of Ni radical razor blade obtains apparent solid dissolve aggrandizement thereby, obdurability rises significantly; Mutual diffused junction combines another part alloying element, form the horniness photograph with a variety of extremely tall hardness, the dissolve that adds WC horniness photograph is entered, they are dispersedly equably in matrix of Ni radical razor blade, make matrix obtains dispersion aggrandizement and fine brilliant aggrandizement, raised the obdurability of matrix further. In the meantime, what in be being organized as a result of coating, form basically is organization of W7Cx horniness appearance (the W3Cx) with meshy and rather than, it has tenacity the characteristic with good, not easy and outspread crackle, can restrict material happening fragile cracked trend, enhanced the tenacity of coating composite material further thereby. In this experiment, what add horniness photograph powder to include WC grain powder for Ni, it overcame common WC grain and Ni base the defect with the poor wellability between bit matrix, make the binding energy force between WC grain and base material increases, matrix photograph also rises accordingly to the supportability of horniness photograph, both a defect that be differred because of wellability and causes is apparent decrease. Graph 1 not coating is mixed wear curve of contrast of razor blade of coating of Ni radical, Ni-W radical pursues 2, graph 3 it is respectively not coating razor blade is mixed point of a knife of razor blade of Ni-W radical coating wears away the photograph of scanning report lens of form appearance. By the graph 3 visible, razor blade of Ni-W radical coating did not produce coating to flake in cutting process, and cutting performance is steady. And by the graph 4 show the photograph of scanning report lens of razor blade of Ni radical coating to see, when VBmax=0.
When 23mm, of razor blade of Ni radical coating before knife range occurred coating to flake phenomenon. Analyse its reason, basically be the be caused by of the tumour that accumulate bits of the generation in cutting process. As a result of the Ni without abrade processing base surface of coating razor blade is rougher, resistance of the attrition when face of the knife before the edge that cut bits is poured out of is greater, on knife face uneven the tumour accumulating bits with easy larger generation. Below fixed cutting rate, of the tumour that accumulate bits generate reach fall off often generation of pair of Ni radical coating are periodic come off action, make break arises between the interface between Ni radical coating and matrix and crystal boundary, bring about Ni radical coating finally to flake. In addition, because cooling fluid was used in cutting, cut the Ni when be being cut every time base coating all can bear greater periodic thermal stress, this also is one of matters that make Ni radical coating flake. By the graph 4 knowable, of Ni radical coating flake the tumor accumulating bits that basically produces advanced knife range is stuck receive place and answer relatively with this place hind knife face. Pass before be opposite, hind each feature dot has area of knife face and point of a knife, point metallic bougie can chart is analysed (the analysis sees watch 2) as a result, afore-mentioned analysises that prove causes of pair of damaged of razor blade of Ni radical coating are reasonable. Accordingly, right of razor blade of Ni radical coating before knife face undertakes proper and abrade can improve bit effectively fight damaged ability. To the bit reentry after face of the knife before classics is abrade travel cutting experiments, its point of a knife wears away the photograph of scanning report lens of form appearance is shown 5 times like the graph, it and the Ni without abrade processing base the comparative wear curve of coating razor blade sees a picture 6. Test result proves, abrade before knife face can be reduced significantly cut bits the conglutinate degree to bit, reduce those who accumulate bits tumour to produce degree and generation frequency thereby, make bit cutting function is obtained bigger rise, what can keep longer below taller cutting speed is normal wear away. Pursue 2 not the point of a knife of coating razor blade wears away 3 Ni-W of form appearance graph base the point of a knife of coating razor blade wears away form appearance pursues the 4 Ni without abrade processing base coating razor blade falls off area form appearance pursues the Ni of face of the knife before 5 classics are abrade base point of a knife of coating razor blade wears away form appearance pursues 6 abrade.
84 not coating razor blade wears away area - 0.
77 not face of the knife after coating razor blade 0.
Area of coating of razor blade of 35Ni radical coating 1.
Razor blade of 17Ni radical coating wears away area 0.
Face of the knife before point of a knife of razor blade of 17Ni radical coating - 0.
Face of the knife after point of a knife of razor blade of 37Ni radical coating 1.
Face of the knife before razor blade of 89Ni radical coating falls off wear away area 0.
White Area of point of blade of 26W radical coating 0.
Razor blade of 76W radical coating wears away area - 0.
Black area of point of blade of 47W radical coating 0.
Face of the knife after razor blade of 89W radical coating wears away area - 0.
93 average 0.
545 the least values - 0.
35 maximum 1.
264 conclusion Ni base, razor blade of Ni-W radical coating leaves cutting course in this experiment condition smooth, smooth, coefficient of friction is lesser, durability relatively not coating razor blade has relatively rise substantially, cutting performance is relatively good. Before razor blade of Ni radical coating is besmearing Fu is handled, hind pass proper and abrade face of the knife before its, can raise bit coating effectively fight flake ability. When coating material uses Ni to wrap WC grain powder to serve as horniness photograph, can enhance the binding energy power between WC grain and base material, improve matrix appearance the supportability to horniness photograph, can decrease apparently both a defect that be differred because of wellability and causes. CNC Milling