In dry machining, the tool-chip interface temperature is a critical factor affecting the engineering performance of WC-Co tools. As the temperature variation of the cutting tool in dry machining is similar to that in annealing process, the effect of tool-chip interface temperature on the mechanical properties of cutting tool materials in dry machining can be studied by means of annealing experiment. In this paper, a series of annealing experiments of ultrafine-grained WC-Co materials were conducted, and the effects of the annealing temperature and holding time on the mechanical properties of WC-Co materials, including flexural strength, hardness and fracture toughness, were investigated. The results show that under the experimental conditions, the annealing temperature dominates the mechanical properties of WC-Co materials. The flexural strength and fracture toughness of the ultrafine-grained WC-Co materials decrease in different extent with increasing of annealing temperature, whereas the hardness does not change obviously. The measurements of the microstructures and residual stresses revealed that the deterioration of mechanical properties of WC-Co materials after annealing can be attributed to the relaxation of compressive residual stress.

Abstract.Functionally gradient WC-Co composites having a Co depleted surface zone and not comprising the Ș phase can be manufactured via carburizing process. During carburizing, besides carburizing process parameters, the microstructural parameters of WC-Co materials, such as WC grain size and Co content, also have significant influences on the formation of Co gradient structure. In this study, the effects of WC particle size and Co content on the gradient structure within gradient hardmetals have been studied, based on a series of carburizing experiments of WC-Co materials with different WC particle sizes and cobalt contents. The results show that both the thickness and the amplitude of the gradients within gradient WC-Co materials increase with increasing initial WC particle size and Co content of WC-Co alloys. The reason for this finding is discussed.

Background. Stroke is a common cerebrovascular disease among the middle-aged and elderly, which can lead to a series of neurological disorders. Acupuncture is an important part of traditional Chinese medicine, with great value in improving the neurological deficits of stroke patients. In addition, rehabilitation therapy is also of great significance for alleviating the neurological deficits of patients and improving their activities of daily living. Objective. To explore the effect of acupuncture and moxibustion combined with rehabilitation therapy on the recovery of neurological function and prognosis of stroke patients. Methods. The case data of 100 stroke patients treated in the Wuhan Hospital of Traditional Chinese Medicine from January 2019 to July 2021 were analyzed retrospectively. According to the treatment plan patients received, they were divided into the following two groups: an observation group ( n = 52 ) treated with acupuncture combined with rehabilitation therapy and a control group ( n = 48 ) treated with rehabilitation therapy alone. The two groups were compared in terms of the following items: therapeutic efficacy, plasma levels of cortisol (Cor) and neuropeptide Y (NPY), nerve function, motor function, balance ability, self-care ability, swallowing function, negative emotions, and quality of life. Results. The therapeutic effect of the observation group was significantly higher than that of the control group ( P < 0.05 ). The levels of Cor and NPY, as well as the neurological function, motor function, balance ability, self-care ability, swallowing function, and negative emotions, were not significantly different between the two groups before treatment ( P > 0.05 ). While after intervention, all the above indexes improved in both groups, with better improvements in the observation group compared with the control group ( P < 0.05 ). And the various dimensions concerning the quality of life of patients were also significantly better in the observation group when compared with the control group. Conclusion. Acupuncture of traditional Chinese medicine combined with rehabilitation therapy has outstanding effects in stroke treatment and can effectively improve the neurological function, prognosis, and quality of life of patients, which is worthy of clinical promotion.