Residual stress could be induced by machining processes like milling which can greatly affect the fatigue life of fabricated parts, especially in dynamic loading conditions. In metal cutting operations, machining induced residual stresses can be explained in the terms of machining forces and temperatures of the cutting zones. This thermo mechanical loading along with the resulted metallurgical changes are the main sources of residual stresses generation at the surface of machined workpiece. Researchers have proved the superior properties of nanofluids over the conventional coolants to reduce the intensity of thermo mechanical loading in machining process which will affect the residual stresses caused by machining. Therefore, in this paper, silver nanoparticles in the water-soluble oil have been used for reducing the mechanical and thermal loads in the milling process. The cutting forces, temperature of the cutting zone, surface roughness and the residual stress of machined surface have been measured experimentally in milling of hardened steel AISI 4140 for various nanoparticle’s concentration, feeds and cutting speeds. Results show that increasing the concentration of Nano-particles in base fluid from 0.5 to 3.0% wt., will make machining surface residual stresses more compressive averagely by about 66.67% compared to conventional cutting fluid.

铣削之类的加工过程可能会产生残余应力，这会极大地影响已加工零件的疲劳寿命，尤其是在动态载荷条件下。在金属切削操作中，可以通过切削力和切削区域的温度来解释机加工引起的残余应力。这种热机械载荷以及所产生的冶金变化是在加工工件表面产生残余应力的主要来源。研究人员已经证明，纳米流体比常规冷却剂具有优越的性能，可以降低加工过程中的热机械负荷强度，从而降低机械加工引起的残余应力。因此，在本文中，水溶性油中的银纳米颗粒已用于减少研磨过程中的机械和热负荷。切削力，切削区域的温度，表面粗糙度和机加工表面的残余应力已在AISI 4140淬硬钢的铣削中针对各种纳米颗粒的浓度，进料和切削速度进行了实验测量。结果表明，与常规切削液相比，将纳米粒子在基础液中的浓度从0.5％增至3.0％wt，将使加工表面残余应力平均平均压缩约66.67％。在铣削硬化的AISI 4140钢时，已针对各种纳米颗粒的浓度，进给和切削速度，通过实验测量了表面粗糙度和机加工表面的残余应力。结果表明，与常规切削液相比，将纳米粒子在基础液中的浓度从0.5％增至3.0％wt，将使加工表面残余应力平均平均压缩约66.67％。在铣削硬化的AISI 4140钢时，已针对各种纳米颗粒的浓度，进给和切削速度，通过实验测量了表面粗糙度和机加工表面的残余应力。结果表明，与常规切削液相比，将纳米粒子在基础液中的浓度从0.5％增至3.0％wt，将使加工表面残余应力平均平均压缩约66.67％。