Zhao Hongrui, Sun Qun, Wang Chong, Yuan Xiuhua, Li Xia
School of Mechanical and Automotive Engineering, Liaocheng University, Liaocheng 252000, China.
School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252000, China.
Molecules. 2024 Dec 16;29(24):5925. doi: 10.3390/molecules29245925.
Diamond grinding wheels have been widely used to remove the residual features of cast parts, such as parting lines and pouring risers. However, diamond grains are prone to chemical wear as a result of their strong interaction with ferrous metals. To mitigate this wear, this study proposes the use of a novel water-based hexagonal boron nitride (hBN) as a minimum quantity lubrication (MQL) during the grinding of cast steel and conducted the grinding experiment and molecular dynamics simulation. The experiment demonstrated that compared to dry grinding, the water-based hBN nanofluid can effectively reduce the maximum temperature of a workpiece at contact zone from 408 K to 335 K and change the serious abrasion wear of diamond grain to slightly micro-broken. The molecular dynamics simulation indicates that the flake of hBN can weaken the catalytic effect of iron on the diamond, prevent the diffusion of carbon atom to cast steel, and suppress the graphitization of diamond grain. Additionally, the flake of hBN improves the contact state between the diamond grain and cast steel and reduces the cutting heat and friction coefficient from about 0.5 to 0.25. Thus, the water-based hBN nanofluid as a new MQL was proven to be suitable for the wear inhibition of diamond grain when grinding cast steel.
金刚石砂轮已被广泛用于去除铸件的残留特征，如分型线和浇冒口。然而，由于金刚石颗粒与黑色金属的强烈相互作用，它们容易发生化学磨损。为了减轻这种磨损，本研究提出在铸钢磨削过程中使用一种新型的水基六方氮化硼（hBN）作为微量润滑（MQL），并进行了磨削实验和分子动力学模拟。实验表明，与干磨相比，水基hBN纳米流体可以有效地将工件接触区的最高温度从408K降低到335K，并将金刚石颗粒的严重磨粒磨损转变为轻微的微观破碎。分子动力学模拟表明，hBN薄片可以减弱铁对金刚石的催化作用，防止碳原子向铸钢扩散，并抑制金刚石颗粒的石墨化。此外，hBN薄片改善了金刚石颗粒与铸钢之间的接触状态，并将切削热和摩擦系数从约0.5降低到0.25。因此，水基hBN纳米流体作为一种新型的微量润滑被证明适用于铸钢磨削时金刚石颗粒的磨损抑制。
