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The corrosion resistance layers can be surfaced in the valve casted by carbon steel, to enhance the corrosion resistance performance. By the 3D solid model, the weight and internal area of valve body was obtained. The surfacing process was designed and the welding rods theory amount was calculated. And the actual amount was close to the theory one. The surfacing and cutting process was designed for the fit surfaces and the dimension chain was calculated to meet the fit accuracy and the corrosion resistance layer thickness. The results show that it has the engineering significance by using 3D solid model to estimate the producing costs; the fit accuracy and the corrosion resistance layer thickness can be obtained together based on the surfacing and cutting process; in this way, the cost can be cut down more than 30%, compared the whole stainless steel valve.

For investigating the effect of ultrasonic treatment on the cooling and lubricating action of cutting fluid, an ultrasonic treatment system of emulsion fluid was developed to be used in cutting experiments. And the comparison experiments were carried out with YT15 tool turning 45 steel, under the conditions of dry cutting, fluid and ultrasonic treatment fluid. The results show that as ultrasonic treatment one used cutting forces decrease about 10%-15% and 5%-10% to dry cutting and fluid; the cutting deformation coefficients reduce too; and the machined surfaces are enhanced. Therefore, the cooling and lubricating performances of the fluid are improved by ultrasonic treatment. As a result, the using quantity of emulsion fluid would reduce indirectly, and this help to energy saving and emission reducing.

This study focuses on estimation of clutter degrees of freedom (DOFs) for airborne multiple-input multiple-output (MIMO)-phased array radar. Firstly, two equivalent clutter models are presented, according to the transmitting subarray beampattern and synthetic-phased centre, and based on the basic steering vector. Secondly, a convenient estimating rule of clutter DOFs for airborne MIMO-phased array radar under arbitrary transmitting subarray structures is presented and proofed strictly. Finally, the simulated results indicate that airborne MIMO-phased array radar is effective both in spatial selectivity and clutter suppression, and the clutter DOFs under arbitrary transmitted subarray structures can be estimated by the proposed rule exactly. The proposed models and rule are suitable for both conventional-phased array radar and airborne MIMO radar with uniform or non-uniform transmitting subarray and sparse array, and they are valuable for the improvement of space-time adaptive processing algorithm performance.

The machining process of titanium alloys always need special control by using coolant and lubricant as it is one of the difficult-to-cut materials. The cutting experiments are carried out based on green cooling and lubricating technology. To achieve green cutting of titanium alloy Ti-6Al-4V with water vapor cooling and lubricating, a minitype generator is developed. Compared to dry and wet cutting, the using of water vapor decreases the cutting force and the cutting temperature respectively; enhances the machined surface. And it can help to chip forming and breaking. Water vapor application also improves Ti-6Al-4V machinability. The excellent cooling and lubricating action of water vapor could be summarized that water molecule has polarity, small diameter and high speed, can be easily and rapidly to proceed adsorption in the cutting zone. The results indicate that the using of water vapor has the potential to attain the green cutting of titanium alloy.

Green cutting is one of the developing tends in the industry field. Water vapor can be introduced in metal cutting as coolant and lubricant due to its pollution-free, generating easily and unneeded disposal. Therefore, a special generating system is developed to produce suitable water vapor, and a simulation to the velocity of water vapor jet flow is presented. Then tool wear was investigated and a new capillary model is proposed, based on the experimental results. According to the boundary-layer theory, the kinetics equations of flow were solute. The velocity and flux of molecule are presented. In the capillary, the adsorption of tool-chip interface results in boundary lubricating film; the conical shape of capillary limits the depth of coolant and lubricant penetrating; and the negative press is the motility for coolant and lubricant penetrating. The study results show water vapor can decrease tool wear about 10% times and 20% comparing to cutting fluids and dry cutting, and water vapor could be a potential solution of green cutting.

The gases of nitrogen, oxygen, argon and carbon dioxide were employed as coolant and lubricant in metal cutting. Therefore, the smaller kinetic diameter of gas, the lower cutting forces can be obtained. A conical capillary model is proposed, based on the experimental results and the theory analysis of stress distributions at the tool-chip interface. According to the boundary-layer theory, the kinetics equations of gas flow were solute. The velocity and flux of gas molecule are presented. In the capillary, the adsorption of tool-chip interface results in boundary lubricating film; the conical shape of capillary limits the depth of coolant and lubricant penetrating; and the negative press is the motility for coolant and lubricant penetrating. The study results show the molecule size of the coolant and lubricant could effect on its performances, and the coolant and lubricant with a relatively small molecule may have the particularly effective nature, in metal cutting.

To investigate the effects of gases as coolant and lubricant on machined surface, the micrograph and roughness value were obtained face to green cutting. Under the experiment conditions, water vapor and nitrogen gas may give a better restrain action to nubs adhibiting on the machined surface. And water vapor gave the lowest roughness value, while nitrogen gas has hardly help to lower roughness value. Other gases, only at a certain extent, can restrain nubs adhibiting and lower roughness value. Common characters of these gases are widely source, out of pollution, needless to disposing and so forth. With the view point of environment friendly, these gases may achieve green cutting.

The copper - aluminum pipe has been widely used in the refrigeration industry. And the welding quality becomes the focus. A PLC control system was developed to accurately control the resistance welding process of the Cu-Al pipe. The welding voltage was adjusted by a couple of silicon controlled rectifiers (SCR). To restrain the effect of network voltage fluctuation on the welding heat generation, it was obtained that the experimental relationship of the angle of flow and the network voltage, and fitted to a quadratic polynomial equation. Therefore, the control system can calculate the exactly the angle of flow value according to the current network voltage. The experiment results show that the error of the welding heat generation is limited in 5% when the network voltage fluctuates in the range of 380V ±10%. And the SEM and EDS analyzing results suggests that the welding seam length is more than 5mm, and there is hardly eutectic composition.

To achieve green machining of titanium alloy Ti-6Al-4V with water steam cooling and lubricating, a 600-800w minitype generator is developed. Compared to dry and water-based emulsion, the using of water steam improves Ti-6Al-4V machinability and prolongs the tool life about 1 time and 0.5 times. And if the same tool life was selected, it would be easy to obtain that as water steam applied the cutting speed can increase about 15% and 10%. As a result, the productivity can be increased. The excellent cooling and lubricating action of water steam could be summarized that water molecule has a small diameter and high speed, can be easily and rapidly to penetrate the capillaries and proceed adsorption in the cutting zone. The results indicate that the using of water steam has the potential to attain the green machining of titanium alloy Ti-6Al-4V.

This paper addresses the issues of clutter characteristics of airborne MIMO radar in presence of degradation of transmit waveforms orthogonality. Firstly, synthesis subarray space and synthesis transmit signal space caused by the degradation are illustrated. Clutter model of airborne MIMO radar is developed under the orthogonal degradation. Clutter models with arbitrary waveform are unified in this model via the transform of array space and signal space. Secondly, an estimation rule for the number of clutter DOFs is presented based on band-limited signal theory. It shows that clutter DOFs is dependent on both the number of inner elements in synthetic subarray and synthetic signal. Finally, clutter characteristics under the influence of degradation are analyzed compared with the ideal MIMO radar model and phase array radar, and the effectivity of the estimation rule is verified in the numerical examination.