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Ball milling process has an important effect on the microstructure and the morphology of final powder products and the corresponding as-sintered samples. In the present study, Ti-7Al-0.2B (wt%) mixed powder was ball-milled by low-energy and high-energy types of ball mills, and then the milled powder was sintered by hot-pressing. On this basis, the morphology evolution of the powder was analyzed, and the microstructures of the reinforcements in the as-sintered composite were investigated. Research results show that in the low-energy ball milling process, mechanical alloying occurs between the powder particles. TiB whiskers formed in sintering process are long and thin without linked coarse crystals bars or clusters. Under the high-energy milling, the average particle size of the powder is refined remarkably to 1 μm, and Ti(Al) supersaturated solid solution or even amorphous structure is formed during the milling process. In the following sintering process, nano-scale TiB whiskers are synthesized and they are uniformly distributed in the matrix.

The endangerment of aeolian sand is one of the most serious eco-environmental problems facing the southern suburb of Beijing. To control wind erosion is thus a matter of great urgency. This paper chooses typical land-use types, i.e., cultivated land, wild grassland, drifting sandy land, etc. based on the fixed experimental observation and quantitative analysis, to conduct studies on the principles and characteristics of aeolian activities and measures controlling wind erosion in Daxing District of Beijing. The results show that: the near ground wind velocity yielded the logarithmic distribution with height; there are significant differences among different ground cover roughness; there are significant differences in the corresponding friction velocities caused by different properties of the underlying surface; there are differences in the threshold wind velocities speed in different land use types; and there are minus exponential relations between the sediment discharge percentage and the height at a range of 0–20 cm air flow layer. Different land use types result in various degrees of coarse component. There is a significant exponential relation between sediment transport concentration and wind velocity.

The threshold wind velocity of a number of variables was studied in four different land-use types: farm land, forestland, wild grassland and a flood plain in the Yongding River sandy land in Beijing. The variables studied were transport of sand, underlying surface roughness, windblown sediment, wind-sand flow structure, soil mechanical composition and amount of wind erosion. The following conclusions were drawn: 1) The order of decreasing threshold of wind speed for sand displacement and surface roughness were forestland, wild grassland, farm land, sparse wild grassland and flood plain. 2) There were significant differences in sand flux among different ground covers. At a height of 0–20 cm, the height increased while the sediment discharge percent of sand flux decreased; there were significant differences in the sand flow formation under different land-use types. 3) The mechanical composition of sand particles consisted mainly of silver sand in the flood plain and sparse wild grassland, and of silver sand, particle silver sand and floury sand in other land-use types. 4) The amounts of wind erosion and sand sediment were different among different land-use types. Increased vegetation cover and change in farming techniques were suggested to prevent and control wind erosion of sand and soil.