Materials undergo various loading conditions during different manufacturing processes, including varying strain rates and temperatures. Research has shown that the deformation of metals and alloys during manufacturing processes such as metal forming, machining, and friction stir welding (FSW), can reach a strain rate ranging from 10⁻¹ to 10⁶ s⁻¹. Hence, studying the flow behavior of materials at different strain rates is important to understanding the material response during manufacturing processes. Experimental data for a low strain rate of 10³ s⁻¹ are readily available by using traditional testing devices such as a servo-hydraulic testing machine and the split Hopkinson pressure bar method, respectively. However, for the intermediate strain rate (10¹ to 10³ s⁻¹), very few testing devices are available. Testing the intermediate strain rate requires a demanding test regime, in which researchers have expanded the use of special instruments. This review paper describes the development and evolution of the existing intermediate strain rate testing devices. They are divided based on the loading mechanism; it includes the high-speed servo-hydraulic testing machines, hybrid testing apparatus, the drop tower, and the flywheel machine. A general description of the testing device is systematically reviewed; which includes the working principles, some critical theories, technological innovation in load measurement techniques, components of the device, basic technical assumption, and measuring techniques. In addition, some research direction on future implementation and development of an intermediate strain rate apparatus is also discussed in detail.

In recent years, many titanium alloys have emerged, each of them associated with a range of different heat treatments. Thus, several microstructures have been studied to varying degrees. For example, the Ti64 titanium alloy, mostly known for its α + β structure, can display a different state: the structure, inducing nonstandard mechanical behavior. This work presents chip formation in this specific microstructure where a strong heterogeneity is observed and where the shear band formation is a function of the relationship between the shear direction and the microstructure orientation. From these reasons, major differences are found in the chip morphology, within the same cutting condition, in comparison to the bimodal structure where a single chip morphology is obtained for each cutting condition. A section of this paper is devoted to the presentation of the β microstructure where different configurations can be seen within the same chip. Next, the influence of cutting conditions on the chip formation is studied. To highlight the specific chip formation process, a temperature model has been developed and combined with cutting force analysis to understand clearly the specificity of the chip formation for this structure. Finally, the discussion explains the different chip formation scenarios according to the workpiece microstructure to be cut.

Purpose: The purpose of this paper is to understand the impact of the cutting forces on the quality of pieces in industrial cutting of multi-ply textile material. It also tries to establish a cutting model that can simulate the cutting forces in order to understand the behaviour of the blade. Design/methodology/approach: Working on an industrial machine, a cutting head with an oscillating knife is instrumented with different sensors. Using this equipment, cutting forces can be analysed experimentally while the fabric is being cut along a straight line. Findings: A model of the physical phenomena of the cutting forces is proposed, taking different parameters into account such as the geometry of the blade, the properties of the material being cut and the parameters of the cut. The simulated forces and the monitored forces are compared and parameters for minimising the cutting forces of fabrics are deduced. Research limitations/implications: Due to the wide diversity of fabrics, all with different mechanical characteristics, this research only began with the study of denim in a straight cut. Originality/value: This paper describes an instrumentation of automatic cutting head for textile. It manages to simulate the action of the fabrics on the blade through effort monitoring and help in the understanding of the multi-ply cutting process.