Laser in-situ synthesis of titanium matrix composite coating with TiB-Ti network-like structure reinforcement

To avoid high crack sensitivity of TiB-Ti composite coating during laser cladding process,network-like structure composite coating was fabricated with laser in-situ technique on titanium alloy using 5 μm TiB2 powder as the cladding material.The microstructure,phase structure and properties of the coatings were analyzed by SEM,XRD,EPMA,TEM,hardness tester and fretting wear meter.It was observed that the outer ring of the network-like structure was mainly TiB strengthening phase,while the inner ring was α-Ti grain,and the interface between TiB and Ti matrix was very clean and had a consistent orientation relationship.The hardness of the cladding layer with network-like structure gradually decreased from the surface toward the interface,but the average hardness was nearly two times that of the substrate.In the fretting wear test,it was found that the wear resistance of the cladding layer with network-like structure was larger than that of the substrate under low load(40 N).The results revealed that the hardness and fretting wear resistance of the titanium-based composite coating could be improved by the introduction of network-like structure.

小针刀松解Frohse弓治疗骨间后神经卡压综合征的临床疗效

目的探讨小针刀松解Frohse弓治疗骨间后神经卡压综合征的临床疗效。方法选取2015年6月—2018年12月于温州医科大学附属第二医院就诊的20例骨间后神经卡压综合征患者使用小针刀疗法松解Frohse弓,观察小针刀治疗该病的疗效及治疗后的恢复情况。使用视觉模拟评分(VAS)评价前臂疼痛分值,英国医学研究会的运动功能恢复等级评定表评定患指伸指肌力等级。结果治疗前和第1周之间、治疗前和第4周之间,以及第1周和第4周之间VAS评分比较,差异均有统计学意义(P<0.05);治疗后第1周与治疗前运动功能恢复比较,差异有统计学意义(P<0.05),治疗后第4周与治疗前运动功能恢复比较,差异有统计学意义(P<0.05)。结论小针刀治疗骨间后神经卡压综合征可显著改善手部功能,其创伤小、疗效好,具有很大的临床应用价值。