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Severe surface hardening problems during laser surface texturing (LST) exert a remarkable influence on the tribological performance and fatigue strength of LST-treated components. Given this, an attempt is made to evaluate the effect of process parameters, including the energy density, the pulse frequency, and the scanning speed, on the hardness of laser surface textured 5A06 aluminum alloy based on response surface methodology. Firstly, a series of LST experiments were carried out by a nanosecond pulsed laser. Then, the predictive model correlating the process parameters with the hardness was established and tested for adequacy using analysis of variance. Sensitivity analysis was subsequently employed to identify and rank the significance of each process parameter. The results indicated that the developed model could effectively predict the hardness of laser surface textured 5A06 aluminum alloy. The scanning speed was found to be the dominant parameter, followed by the pulse frequency, and the energy density has the minimal influence. The graphical results revealed that the hardness gradually increases as the energy density and pulse frequency increases, while decreases as the scanning speed increases. This research could be used to select appropriate process parameters to manufacture high-performance surface textures with superior properties.

To analyze the imaging features of osteopoikilosis and its diagnosis knowledge.The imaging data of 9 patients with osteopoikilosis were analyzed retrospectively, including 6 familial cases and 3 sporadic cases. In 6 familial cases,there were 4 males and 2 females with an average age of 28 years old ranging from 10 to 63 years. Clinical manifestations of 1 familial case were left knee pain and limitation of activity for 3 years, and other 5 cases without clinical manifestation. In 3 sporadic cases, there were 2 males and 1 female with an average age of 33.7 years old ranging from 25 to 44 years. Three sporadic cases had obvious injury history with following up from 6 to 12 months. All imaging results of 9 cases were observed.The imaging data of 6 familial osteopoikilosis showed the multiple round or oval nodes within bone with clear margins, uniform density, different size. The occurrence of the hyperostotic spots preferentially localized in the epiphyses and metaphyses of the long bones, and carpus and tarus. X-ray features of 3 sporadic osteopoikilosis were similar to that of 6 familial cases and for 6 to 12 months follow-up X-ray features were unchanged.The imaging features of osteopoikilosis are relatively specific such as the multiple mottling dense focal within bone with clear border and bilateral symmetry, and the focus located on cancellous bone and the diaphyses usually is unaffected. The imaging is a valuable examination for the accurate diagnosis of osteopoikilosis.