Deadline for manuscript submissions: 31 March 2025.
As a typical high-performance alloy, the excellent mechanical properties and stringent processing requirements of 30CrMnSiNi2A high-strength steel pose great challenges to high-quality and efficient processing. Currently, researchers have proposed methods such as improving cutting tool performance, minimal quantity lubrication (MQL), and applying external energy field to assist processing. However, due to the unregulated material properties, the further improvement of surface quality is limited, and there are problems of phase change and thermal damage in laser processing. Cold plasma jet (CPJ) is rich in active particles and has a low macroscopic temperature. It can effectively regulate material properties without causing serious surface damage. Therefore, a new 30CrMnSiNi2A machining approach adopting CPJ is proposed to improve the cutting process. The mechanism of its action on material properties and cutting process is revealed based on single-grain diamond scratching tests and micro-milling tests. The results show that CPJ can promote material fracture and improve material removal efficiency. The material removal efficiency R at 400 mN is increased from 0.433 before treatment to 0.895. Under the optimal processing parameters (feed speed Vf = 800 μm/s, spindle speed n = 40,000 rpm, and milling depth ap = 5 μm), compared with dry micro-milling, the cutting forces Fz, Fx and Fy in CPJ-assisted micro-milling are reduced by 26.5%, 24.8% and 31.3%, respectively. The surface roughness Sa is reduced by 19.3%, and the phenomena of plastic flow and burr are suppressed. The CPJ-assisted machining process proposed in this paper can regulate the material properties to improve the cutting process without causing serious damage to the material, providing a new approach for achieving high-quality and efficient processing of 30CrMnSiNi2A.
Grinding is widely used in orthopedic surgery to remove bone tissue material, but due to the complex and brittle structure of bone, it is prone to mechanical stresses that cause cracks and damage to the bone tissue. Furthermore, bone replacement materials typically have high hardness, strength, and brittleness, which lead to increased tool wear and damage, such as cracks and deformation during grinding. Therefore, ensuring the surface quality of bone and replacement materials during the grinding process has become a critical issue. This necessitates the development of grinding force models that consider various processing parameters, such as feed rate and cutting depth, to guide industrial production. However, currently, research on the grinding force prediction models for bone tissue and its replacement materials is relatively scarce, and there is a lack of corresponding grinding force model reviews for unified guidance. Based on this, this article focuses on bone grinding technology and, conducts a critical comparative analysis of the grinding force models for bone tissue and its replacement materials, and then summarizes the grinding force prediction models in the grinding process of bone tissue and bone replacement materials. First, according to the material types and material removal mechanisms, the materials are categorized into bone tissue, bio-inert ceramics, and bio-alloys, and the material removal process during grinding is analyzed. Subsequently, the grinding force prediction models for each material and the accuracy errors of each model are summarized. The paper also reviews the application of these grinding force prediction models, explaining how processing parameters such as feed rate and cutting depth influence grinding forces and their interrelationship. Finally, in light of the current issues in the grinding of bone tissue and replacement materials, potential future research directions are proposed, aiming to provide theoretical guidance and technical support for improving the grinding quality of bone tissue and its replacement materials.
Single-crystal silicon (Si) and silicon carbide (SiC) are core semiconductor materials in communication, lighting, power generation, and transportation. However, their high hardness and wear resistance combined with low fracture toughness have posed significant challenges for high-efficiency and low-damage machining. Aqueous suspensions containing nanoparticle additives have recently been developed for sustainable manufacturing due to their satisfactory tribological performance and environmentally friendly nature. In this work, nanoadditives, including two-dimensional (2D) graphene oxide (GO) nanosheets and zero-dimensional (0D) diamond nanoparticles, were ultrasonically dispersed in water to formulate different GO-based nanosuspensions for achieving high-efficiency and low-damage abrasive machining. The experimental results indicated that GO nanosuspension was a suitable coolant for grinding Si, generating a ground surface of 32 nm in Ra, owing to its great lubricity and excellent resistance against mechanical abrasion. Diamond-GO hybrid nanosuspension demonstrated a synergistic effect in abrasion, lubrication and oxidation, which was thus appropriate for polishing SiC single crystals, leading to approximate 60% and 30% improvements in removal and roughness respectively, in comparison to a commercially available diamond suspension.