Containing Titanium-tool Steel In Gdl, The Organization And Performance

The present investigation establishes Ti as an alloying agent in iron-based composites on the bases of the reseach on GDL-4 tool steel whithout Ti.And the wear resistance is compared and analyzed with that on GDL-4 and M2 steel.The TiAlN coating's on appending Ti GDL-4,surface characteristic,bonding strength,mechanical property and wear resistance and so on is studied.Analysing why the wear resistance changes from the hardness of steel,the factors of the friction coefficient,the microstructure and so on in this text.The new kind of GDL-4 steel is used to take the place of the high-cost traditional high-speed steel with the content of 0.5%Ti and cheap Si,Cr,Mn,W as the main additive elements.A few Mo,V and a certain quantities of RE are also added into GDL-4.The hardness of appending Ti GDL-4 has reached HRC60-65 after high temper heat-treat.Appending Ti GDL-4 steel's Properties is pretty similar to that of M2 from normal temperature to 400℃.But GDL-4'cost is only 1/3 than that of M2.The results of X-ray show that residual austenite content in GDL-4,appending Ti GDL-4 and M2 is 13.6%,9.5%and 10%.The micro-hardness has reached HV883, HV924 and HV930,When loading 50g.The new steel has already come to a the tool steel usage request.The result shows that the bonding strength of the film and appending Ti GDL-4 is pretty similar to that of M2.The film thick on appending Ti GDL-4 and nitridation of appending Ti GDL-4 has reached 4.1～4.4μm;4.1～4.5μm is equal to that of M2 (4.1～4.6μm).The bonding strength is better on PVDTiAlN coating after nitriding of appending Ti GDL-4 because the hardness of surface is HV1362 and there is a better gradient layer and the hardness of PVDTiAlN coating reach HV2377.1t is obviously higher than other tow states.The residual stress in nitridation of appending Ti GDL-4 after PVDTiAlN coating is -347MPa,M2 is -336MPa and appending Ti GDL-4 is -309MPa.The experiment of wear resistance shows the coefficient of friction is constant in uncoating's samples and that increases in coating materials from 300N to 500N.The fluctuation of coefficient of friction in appending Ti GDL-4 PVDTiAlN is biger than nitridation of appending Ti GDL-4 PVDTiAlN and M2 PVDTiAlN.The difference of coefficient of friction between tow states is the change of wear mechanism.From wore away quantity,appending Ti GDL-4 is lower than M2 under the loads of 300N and 400N and similar to it under the loads of 500N.They both lower than GDL-4 without Ti.In PVDTiAlN coating samples,nitridation of appending Ti GDL-4 is higer than M2 under 300N and similar to M2 under 400N but lower than M2 under 500N. The immediate PVDTiAlN coating samples' wore away quantity is biggest.From pattern of wore samples we find the wear mechanism of uncoating's samples is particle wear with it's typical pattern- plough ditch and PVDTiAlN coating's samples is adhesive wear- glue wear and transformation.They both aggravate in company with the increase of loads.This is because the change of friction material results in the change of wear mechanism.