Cutting cutting tool is multilayer the mechanical character of coating and wearability
- source:GEOFF CNC Machining
The raw material such as 50%CO2, chemical pure TiCl4 and AlCl3, handle passivation of classics of hard alloy matrix, clean, outfit furnace and after warming up, deposit CVD coating is cooling, make so that wait for namely survey coating sample. The ply of 4 kinds of coating is respectively 4.
5µm and 1.
5µm. 2 tests result and discuss mechanical function to use accept rice sclerometer to undertake to 4 kinds of coating impress experiments, get is in to load and the load in uninstalling a process and the relation curve that press deepness. E is stretch model quantity, HV is the value of diamond pyramid hardness of coating, the method that waits according to Oliver is affirmatory. This method uninstalls a curve besides the consideration outside, still considered pressure head appearance and press deepness to calculate suffer carry the interface below to accumulate, hardness is inspected susceptive of the material in uninstalling a process is average pressure. Multilayer the coating of monolayer of carrying capacity excel of coating. The Li coating in using analysis of accept rice sclerometer to control a process discovers when all sorts of crackle processes of exterior happening, the tall stress that contacts an area makes the crackle of the first approximate and annular penetrable film layer appears all round pressure head; Very high lateral pressure makes coating / matrix interface happens to come off and break off in osculatory area; The brim point that loses film in the turn appears as a result of the action that curves stress the crackle of the 2nd approximate and annular penetrable film layer or crackle fragment. In the first phase, if coating appears the crackle of approximate and annular penetrable film layer, corresponding ground will appear on P-h curve a step, won't appear conversely step. We studied the invalidation feature of 4 kinds of coating. Visible, as the addition that presses load, appear on P-h curve step, show produce in coating a few the flaw that shows approximate and annular penetrable film layer. The crackle of 1 in coating of every step correspondence approximate and annular penetrable film layers, because this defines step,the load Pf of place ruptures for coating the critical load of invalidation. Such by press a curve attainable of 4 kinds of coating rupture be no longer in force is critical load door is respectively 11.
5mN and 56.
3mN. Visible and multilayer of coating rupture invalidation load is apparent coating of TiN of prep above monolayer; Follow coating number of plies increase, its are critical the value increases load Psub>f. Because,this is multilayer in coating in ask what the layer can prevent crackle to produce with patulous (intermediate layer prevents the ability that crackle is produced and expands to be the same as its ply and number of plies to concern) . According to some document account, of coating rupture tenacity Ksub>IC can calculate by next type: E and V measure He Bosong to compare for the stretch model of coating; 2pRC is the length of the crackle in coating; T is coating ply; U can change for the meet an emergency of crackle occurrence around. Area of P-h music on-line mirrorred coating / of matrix system play plasticity to be out of shape can, the strain that generation releases the 1st times when the crackle of layer of annular and penetrable film approximately can U can accumulate computation according to what music on-line step is in to get. The Kazmanli steps leading up to a house that also described P-h curve to go up concerns with what crackle forms. By type (1) calculates what can get 4 kinds of coat to rupture tenacity is respectively 1.
51MPa · M½ , 2.
18MPa · M½ , 3.
4MPa · M½ and 3.
9MPa · M½ . See what count as coating layer increase, its rupture tenacity value increases. But use multilayer coating, raised the complexity of craft and cost, reason should choose appropriate number of plies. For this we are recommended use TiN/Ti(C, n)/TiC/Ti(C, n)/TiC coating. P-h curve described coating to rupture the circumstance of invalidation; And can mirror anti-friction wear-resisting coating to rupture with P-h2 curve the coating before invalidation / matrix bound and change, especially multilayer the interface between coating changes. To monomer photograph material, the plasticity in pressing deepness be out of shape heft Hp, flexibility be out of shape heft He, press deepness H always: F and Y are the parameter that concerns with appearance of pressure head geometry; P is load; HV is hardness; E is stretch model quantity. Because this can get P=Kh2, k plays plasticity parameter for Loubet. To monad photograph material control a process, p ∝ H2. Study coating / when matrix system, the linear Duan Fu that inflection point reachs from origin on the P-h2 relation curve that discovers its are typical adds up to P ∝ H2 to concern, mirrorred coating play plasticity to be out of shape. Contact theoretical analysis according to Hertz, in discovering the greatest shearing stress still is located in the coating that is pressed, and end can make matrix generation succumbs, because of report of this straight line segment is of coating merely,be out of shape circumstance. After negotiating inflection point, very tall cutting stress makes matrix generation succumbs, make coating happening turn is folded thereby, interfacial happening changes, in desorption of interface of the part in uninstalling a process, in pull the contact below stress action material appears to pile up all round the area, till be in,step is in occurrence crackle. The critical load that because this uses inflection point to handle load,changes, p-h2 and P-h curve are complete mirrorred coating to the interface changes and rupture the whole process of invalidation. The P-h2 curve of 4 kinds of coating, dotted line is those who accord with P ∝ H2 is linear, solid line is the P-h2 curve that is pressed into the process, inflection point is located in the detached dot of solid line and dotted line. Go to of a line segment report of inflection point is coating itself to be out of shape from origin circumstance, inflection point is in load to be worth the load cost that manages under step. Through SFM observation can discover below corresponding step load coating surface appears crackle. By press test data knowable, monolayer TiN coating is in Pi=3.
13 MN place produces interfacial change, the interfacial couple that makes clear monolayer coating is younger, the tenacity of coating is poorer also. And TiN/Ti(C, n)/TiC coating is in Pi=7.
Interfacial change produces when 5 MN. All be straight line segment to step from origin () of coincide of solid, dotted line, explain 2 kinds of coating are in rupture the end before invalidation produces apparent interfacial change. Reason TiN/Ti(C, n)/TiC/Ti(C, n)/TiC and TiN/Ti(C, n)/TiC/Ti(C, n)/TiC/Ti(C, n)/TiC is multilayer coating has higher interfacial intensity and better tenacity. Surface of material of wearability brittleness coating happens in attrition process rupture, come off reach broken, at this moment the wearability of coating basically depends on of material fight fragile decide capacity. Accordingly, the strength that increases material and rupture tenacity can raise its wearability. The quality factor that considers data (the temperature that takes no account of attrition area here and chemistry wear away wait for an influence, if when temperature is affected, the consideration needs to undertake correction) , the wearability WR of coating material can express to be: WR=KIC0.
In 43(4) type: WR is wearability; KIC is rupture tenacity (MPa · M½); E is measured for stretch model (GPa) ; HV is hardness (GPa) . Next watches listed according to type (the wearability of 4 kinds of coat that 4) computation gets. Can see from which, tiN/Ti(C, n)/TiC/Ti(C, n)/TiC/Ti(C, n)/TiC coating wearability is best, its result and photograph of cutting test result - send. Cutting test result makes clear, the TiN/Ti(C in 4 kinds of coating that inspect, n)/TiC/Ti(C, n)/TiC/Ti(C, the service life of N)/TiC coating cutting tool is the longest. Express the mechanical character of 1 coating and M½)WRTiN3 of · of wearability coating Pi(mN)pf(mN)KIC(MPa.
42TiN/Ti(C, n)/TiC/Ti(C, n)/TiC-35.
61TiN/Ti(C, n)/TiC/Ti(C, n)/TiC/Ti(C, n)/TiC-56.
The formation of the crackle in 843 conclusion coating is the same as load and the steps leading up to a house that control deepness curve to go up to have very good corresponding concern. Mix with load and the smooth force curve that press deepness load and the mechanical character that press deepness curve to be able to depict coating material thoroughly. Load and the steps leading up to a house that control deepness curve to go up can use at depicting coat rupture invalidation, and the heavy line segment on load and the square curve that press deepness is usable at the description multilayer the interface of coating changes. Of coating rupture invalidation and interfacial change can use critical load Pf and Pi to be described respectively. Multilayer coating has taller hardness, rupture tenacity and wearability. Follow coating number of plies increase, pf of its limit load and Pi value tend increase. Among them TiN/Ti(C, n)/TiC/Ti (C, n)/TiC/Ti(C, the mechanical function of N)/TiC coating and wearability are best. CNC Milling CNC Machining