Lubrication Technology Research In NC Incremental Forming

The NC incremental forming process is a new sheet metal forming method. Due to advantages of highflexibility, low-cost and short lead-time, recently, this technology has been received wide attentionand research by the scholars all around the world, the study of friction and lubrication technology inincremental forming has the significant influence on the improvement of component surface quality.As a new plastic forming technology, the friction mechanism of incremental forming is different fromother methods. Firstly, this paper propose the friction, wear and lubrication mechanism of incrementalforming on the base of the incremental forming trait; Second, from the surface treatment of sheetmetal and tool, study the lubrication technology in incremental forming of SUS304and LY12sheet,and according to the different traits of two sheets, obtain the proper lubricant methods; At last, studythe influence of the incremental forming process parameters on component surface quality, and theinfluence of lubricant method on sheet metal formability and spring back.The main study and results are as follows:(1) the friction of incremental forming is a kind of mixedfriction, different area has the different friction; abrasive wear and adhesive wear are the main wear inincremental forming.(2) The oxalate treatment is the most appropriate surface treatment for SUS304sheet in incremental forming, it could generate the oxalic acidated film on the sheet as the lubricationcarrier after this treatment, which could absorb the lubrication tightly and transfer the friction to softmaterial inside.(3) the HSS tool surface can generate a high hardness and good wear resistance TiAlNcoating after the PVD treatment, this TiAlN coating could prevent the adhesion of tool and sheet inincremental forming and reduce the wear.(4) The LY12sheet surface can form the good wearresistance anodic film after the anodic oxidation, which can prevent the abrasive wear; theself-lubricating Al2O3/PTFE coating after the composite anodic oxidation doesn’t have the lubricanteffect under the high pressure in incremental forming.(5) Among the process parameters ofincremental forming, the feed rate and forming angle have no effect on component surface quality;When the tool diameter increases, the component surface quality also improves some; But when thepitch increases, the component surface roughness increases a lot; the effective lubricant method couldimprove the sheet metal incremental formability, and also can reduce the component spring back toimprove the forming accuracy.