Study On The Lubrication Properties Of Clay Minerals

In the metal forming process, lubricant is key to ensure the product quality and life of the die. Nowadays, the graphite lubricant and mineral oil lubricant have occupied the main lubricant market,but the environmental pollution and waste of resources are serious. Based on these traditional problems, the paper studied a water-based clay mineral lubricant, it’s a new type of environmentally friendly and resource-saving lubricant, it can not only reduce the pollution of the environment, to curb the phenomenon of energy waste, but also can reduce the production cost and it will have a broad application market.According to the design route: lubricant preparation �'performance testing�'improving�'test again�'the friction mechanism analysis, the properties of clay lubricant and water-based graphite lubricant are judged on the friction coefficient, wear scar diameter and other physical properties, and further optimization will be made for the deficiency of original lubricant.Based on the variation of the friction coefficient, the paper made investigations in various thickener、clay、the concentration of boric acid and lubricating additive concentrations in the preparation of lubricant. Results indicated that the mineral clay lubricant composed of sodium carboxymethylcellulose、brucite、boric acid and sodium fluoroborate performed a good lubricating properties; Friction coefficients are decreased with the increasing of brucite, boric acid, sodium acid fluoride concentration, the best lubricating effect is reached in 12wt%、6wt%、1wt% respectively; On the orthogonal optimization test, the best ratio of lubricants is: brucite: boric acid: sodium fluoborate =12:7:0.5, its friction coefficient is 0.032, while 0.075 from graphite lubricant, the lubrication effect is improved by 57.3%.In performance test, the original mineral clay lubricant is difficult to achieve good lubrication effect at low speed, high load conditions, meanwhile, large of white adhesion can’t be washed away after combustion at high temperature. Thus,the experiment adopt two methods respectively to improve by adding binder(aluminum two hydrogen phosphate) or another clay(hydrotalcite(clay D)、talc(clay E)、mica(clay H)), results showing: The p H value and physical stability of lubricant is decreased with addition of aluminum two hydrogen phosphate, as well, the abrasive wear reduced the effect of lubrication and antifriction; However, the method of clay composite not only improves the tribological properties of lubricant, but also reduce the adhesive residue, and improve the physical stability; Among them, the optimization effect of the composite lubricant with 2wt% of clay D is best, which achieved same effect with water-based graphite lubricant, in the condition of low speed friction, short time, high load, friction reducing properties of composite lubricant was increased by 45.65% than the original one, and 25.2% than the graphite lubricant; At high speed, high load,long time, the lubrication effect is increased by 9.9% and 45.7% respectively; In the antifriction testing, the wear scar diameter is 0.70 mm, it reduced 0.02 mm than before; It has same PB(431.64N) with original clay and graphite lubricant; There is no obvious residual adhesive on the steel pipe surface after combustion for 30 s at 950℃and scouring in water.The SEM topography and EDS element analysis of wear spot and friction film addicted: In the initial friction stage, the lubricant separate two contact surface friction by adhesive film to reduce friction coefficient; At sustained high speed, high load and long time condition, active element in lubricant react with substrate to form B2O3、Fe F2, the kind of chemical reaction film will reduce the friction, and D is conducive to the chemical reaction, the total content of F and B elements reaches maximum value(33.92wt%) when the dosage of D is 2wt%, and the friction reduction and antifriction effect is best.