With the development of electric vehicles, much attention has been paid to the thermal management of batteries. The liquid cooling has been increasingly used instead of other cooling methods, such as air cooling and phase change material cooling. In this article, a lithium iron phosphate battery was used to design a standard module including two cooling plates. A single battery numerical model was first created and verified as the basis of the module heat transfer model. Orthogonal experimental design method was adopted in the module thermal model to optimize the main parameters in the module: Battery gap, the cross-section size, and the number of coolant channels of the cooling plate. The Surrogate Model was then utilized to further optimize geometry of the cooling plate. Finally, the optimized geometry was rebuilt in the module thermal model for analysis. The comparison showed that the maximum and minimum temperature difference in the cooling plate was reduced by 9.5% and the pressure drop was reduced by 16.88%. It was found that the battery temperature difference and the pressure drop decreased with the increase of the cross-section and number of the coolant channel when the coolant flow rate was constant at the inlet.

The application fields of friction stir welding technology, such as aerospace and transportation, has high safety requirements and fatigue is the dominant failure mode for weldments. It is of great significance to understand the fatigue properties of friction stir welded joints. This paper provides an overview of the fatigue mechanism, influencing factors, crack growth rate, and fatigue life assessment. It is found that the fatigue performance of friction stir welded joints can be affected by welding process parameters, test environment, stress ratio, residual stress, and weld defect. The optimized process parameters can produce high quality weld and increase the weld fatigue life. Laser peening is an effective post weld treatment to decrease fatigue crack growth rate and improve material fatigue life.

In this work, friction surfacing (FS) of AA5083 on a DH36 steel substrate was experimentally studied. The process parameters such as rotation speed, travel speed and feed rate are of great significance to the success of the FS process. Seven friction surfaced plates with different combinations of parameters were examined. Optical microscopy, SEM and EDS were used to analyse the characteristics of the microstructure and composition of the interface between the surface and the substrate. The results show that the deposition surface quality decreased as the feed rate, travel speed and axial force increased. However, the bond strength increased with higher feed rate, higher rotation speed and lower travel speed. Elemental diffusion of Fe to AA5083 was established, and the intermetallic compound FeAl₃ was produced in the interface.

The established soft pneumatic grippers have the benefit of flexible and compliant gripping, but they cannot withstand lateral loads, due to the low stiffness of soft material. This paper proposes an endoskeleton gripper. The soft action of the finger is performed by air chambers, and the gripping force is transferred by the rigid endoskeleton within the finger. The endoskeleton in the finger is similar to a wristwatch chain; the hinge mechanism permits relative rotation in the working plane but restricts out-of-plane bending, greatly increasing the finger stiffness. The endoskeleton and gripper holder can be 3D-printed with CR-PLA material. The finger was fabricated by molding of silicone gel. The gripper can perform enveloping grasping and pinch grasping operations depending on the object size, weight, and surrounding environment. The finger bending and gripper grasping performance were investigated by experiments and finite element analysis. The fingertip force of the endoskeleton gripper was about 1.45 times higher than that of the gripper without endoskeleton. It was found that the gripper can grasp objects with a maximum diameter of 80.5 mm and a weight of 450 g, which were 80.5% of the finger length and six times the finger self-weight, respectively.

Additive manufacturing as a major component of the “fourth Industrial Revolution” is getting more and more attention. Friction additive manufacturing technology (FAM) is a subdivision of additive manufacturing technology. Because of its solid-state characteristics, deposition by FAM shows better mechanical performance than other technologies such as powder bed fusion technologies. This paper presents a state-of-the-art survey on the development of FAM in three categories: (i) Friction stir additive manufacturing; (ii) Friction surfacing additive manufacturing; (iii) Metal powder assisted additive manufacturing. The underlying principles, process parameters, microstructure, mechanical properties, and existing problems are described and discussed in detail.