Page 49 - 《摩擦学学报》2021年第6期

834 摩 擦 学 学 报 第 41 卷

containing grease were verified to be safe by the Listeria monocytogenes method. After F-Talc was added, the dropping
point of as-prepared composite aluminum-based grease was increased slightly, but F-Talc had little role on the cone
penetration of the as-prepared grease. It was observed that the microscopic morphology of the F-talc powder had a
layered structure, implying that F-Talc had a tendency to split into mackerel scales and exhibited the special lubricity.
Compared with the as-prepared base grease, the epitaxy initial degradation temperature of as-prepared composite
aluminum-based grease containing 1.0% F-Talc increased from 309 ℃ to 320 ℃, corresponding to an increase of about
3.6%. As the final degradation temperature was reached, the residual weight of the as-prepared grease including the F-
Talc additive was more than that of the as-prepared base grease. Therefore, F-Talc can improve the thermal stability of
the as-prepared composite aluminum-based grease. Due to the use of F-Talc, the rubbing stability of the composite
aluminum-based grease was significantly improved. Moreover, the average coefficient of friction of the as-prepared
composite aluminum-based grease decreased from 0.107 to 0.080, corresponding to a decrease of around 25%. The
depth of the wear scar of the steel disc decreased from 87 μm to 51 μm, corresponding to a decrease of about 41%. The
6 3 6 3
wear volume per unit time of steel disc decreased from 5.89×10 μm /min to 3.10×10 μm /min, corresponding to a
decrease of about 47%. Moreover, at the 1.0%F-Talc-containing as-prepared grease, its tribological properties was better
than that of the commercial grease FM 222. As the mass fraction of F-Talc was 1.0%, the corrosion potential of the disc
worn surface increased from −0.462 V to −0.312 V, corresponding to an increase of about 32%, indicating that the
corrosion resistance of the disc wear scar surface was the best. Mechanism analysis showed that part of the layered F-
Talc can be adsorbed on the surface of the rubbing pair, which was equivalent to the sliding of the "sliding bearing", so
as to improve the anti-wear performance of as-prepared composite aluminum-based grease. In addition, the SiO 2 (the
major ingredient of F-Talc) can bring about the role of the repairing and micro-polishing during the rubbing process. The
presence of silicon and magnesium compounds (such as SiO 2 , MgO) and the decrease of Fe concentration on the wear
scar of the steel disc confirmed that complex chemical reactions occurred on the surface of the wear scar zone to form
the lubricating film, thus reducing the probability of direct contact of the ball-steel disc pair and improving the anti-wear
performance of as-prepared composite aluminum-based grease. Hence, the mixed grease with 1.0% F-Talc resulted in
optimal performance, exhibiting promise in food processing industry. These results provide valuable insights into the
development of novel food-grade lubricants.
Key words: food-grade grease; composite aluminum-based; food additives; listeria method; tribological properties

食品安全问题一直是人们关注的焦点，影响食品 PTFE基润滑脂中天然滑石粉具有良好的减摩和绝缘
[5]
安全的因素众多，其中食品装备中润滑材料泄漏造成 性能 ，但天然滑石粉与F-Talc在理化性能上有些差
的污染是重要的原因之一. 为避免这类问题的发生， 异，而当前F-Talc应用于食品级润滑脂的相关报道较少.
在食品包装及生产的部分环节必须使用食品级润滑 在本研究中采用食品级白油为基础油，复合铝为
[1]
材料 . 食品级润滑脂被广泛运用于轴承、链条和导轨 稠化剂，制备出一种食品级的复合铝基润滑脂. 选用
等食品加工装备的关键传动部位，而润滑脂的润滑性 F-Talc为添加剂，通过Q500热重分析仪和MFT-5000摩
能主要取决于所使用的添加剂. 因此，在确保其安全 擦磨损试验机研究了F-Talc质量分数对润滑脂的热稳
的条件下开展新型添加剂的研究将有助于提升润滑 定性及摩擦学性能影响，并通过电化学工作站和X射
脂的服役寿命. 线光电子能谱仪表征摩擦副表面结构，还采用李斯特
鉴于食品级润滑脂安全性的保障，故在选择添加 菌检测法评价了其安全性，并讨论了F-Talc在复合铝
剂时，无毒、无害是首要考虑条件. 食品添加剂因无毒 基润滑脂中作用机制，将为食品级润滑材料的研发提
和无害的特性已被广泛应用于食品加工领域，有望能 供技术参考.

够作为润滑材料添加剂，改善现有食品级润滑材料的
1 试验部分
[2]
摩擦学性能 . 食品级滑石粉(F-Talc)作为一种食品添
加剂，常用于食品助流和脱模，因其具有良好的润滑 1.1 试验材料及润滑脂制备
性能，其在摩擦学领域也有一定的应用，如将滑石粉 选用食品级白油(Zeolpy 900，韩国)作为基础油，
涂覆在防护服上，以此减少COVID-19期间医护人员 苯甲酸(AR，国药集团化学试剂有限公司)、异丙醇铝
[3]
的皮肤损伤 . 此外，在润滑油中滑石粉具有优异的减 (AR，上海麦克林生化科技有限公司)和硬脂酸(AR，国
[4]
摩性能，能够较好地降低铸铁设备的磨损 . 虽然在 药集团化学试剂有限公司)作为稠化剂原料. 其中苯甲