Papers by Author: Shu Zhang

Abstract: The continuous development in the field of protective coatings and the search for newer rust-based anticorrosion with improved properties have led to the emergence of rust-based anticorrosion for high performance organic coatings for corrosion protection. In this study, one such rust-based anticorrosion coating have been formulated and coated over tinplate surfaces. The physical and anticorrosive properties of the coating were evaluated by accelerated laboratory tests (chemic immersion tests). The results are reported and conclusions are drawn in this paper.

Abstract: Three cutting tools, YG610, Si3N4 ceramic tool and CBN were adopted for heat cutting deposited materials. The test results show that though the impacts to the tools reducing, the CBN still break seriously. The condition by Si3N4 ceramic tool is better than CBN, whose types of tool failure change from breakage to wear. The YG610 is best material for heat cutting, whose minimum VB value is only 0.3mm. In the experiment, the wear increase with the increasing of heating temperature, cutting speed, cutting depth. But it decreased with feed rate. The analysis results show that the red-hardness is most importance factor for wears of YG610.

Abstract: The CBN and YG610 were used for remanufacture thermal spray coating cutting. The feed rates, in the experiment, adopt mode of creep feed. The experiment results showed that the YG610 can cut the thermal spray coating efficiently. And the surface finish qualities are all under Ra1, which can come up to the standard of common grinding. But the CBN tools will be broken in the cutting process, though it can perform well in the evenly qualitative material. By experimental investigation and analyses, it can be conclude that both the high hardness and huge impact exist in cutting process, which are main reasons which induce tools broken. So the materials of tools for cutting thermal spray coating need possess both sufficient hardness and toughness.

Abstract: An acrylate emulsion was modified by vinyltriethoxy silane (VTES, trade name A-151) to synthesize the acrylosilane emulsion with high properties. The effect of the amount of A-151 on the properties pf the emulsion was investigated. It found that adding 6 % of A-151, the fraction extensibility of the emulsion film could be increased to 530 % and its water absorption was reduced to 4.2 % while adding 10 % of A-151. On the other side, the particle size and distribution of the emulsion were analyzed by Scanning Electron Microscopy (SEM) and Malvern Particle Size Analyzer (PSA) respectively. The measuring results showed that the particle diameter of the modified emulsion could be between 100 and 700 nanometers, and the properties of the emulsion could be apparently improved by adding A-151 into the system of emulsion polymerization.

Abstract: Axial turn-grinding is a method to cut the cylindrical work piece along its axis, using the kinetic energy of high-speed rotation annularity tool, the abrasives in tool tip as the main cutting edge to remove materials and the abrasives in the inside or outside surface of tool as a minor cutting edge to sharpen the processed surface. Through analysis the simplified model, a slightly stress concentration was found at the junction surface of processed surface and machined surface, which had little damage to the workpiece because of happening in the part to be removed or precision machining allowance, and both cracks propagation caused by material rupture were effective removal after material removal mechanism analysis because the extension of the median/radial crack and lateral crack were both happening in the part to be removed.

Abstract: A series of experiment were performed to test the cleaning ability of different organic emulsion for Si₃N₄ ceramic grinding. The experiment results showed that the grinding fluid made by short chain organic substance and alkane will induces the jam of grinding wheels. At the same time, polar organic substance with long carbon chain can suppress wheel loading phenomenon. The main reason of the jam by alkane is the nonpolar oil film surface possesses the strong attraction to abrasive dust of Si₃N₄, which will lead to jam in the grinding process. The polar oil film relieves the aggregation of abrasive dust in the grinding area to some extant, which is beneficial to decrease jam. By analyzing the cleaning property by some types of polar organic substances, the paper discusses the relationships of molecular structure characters to their cleaning ability.

Abstract: High performance cemented carbide YG610 was adopted for remanufacture hardness deposited materials cutting experiment. The experiment results showed that the same conclusions can be drawn from two group orthogonal experiments. The influence order on cutting capability of cutting tools was: feed rate﹥cutting speed﹥ cutting depth. The cutting length of cutting tools increases monotonously with the feed rate decrease. And the effects by the cutting depth were comparatively small, which is almost negligible in hardness materials cutting. Therefore，low feed rate and large depth of cut are beneficial to keep cutting capability of cutting tools and improve manufacturing productivity. By the results of two orthogonal experiments and extreme deviation analysis, the optimal scheme for cutting parameters were achieved after calculating the best level of the factor.

Abstract: Axial turning-grinding is a processing method to cut the cylindrical workpiece along its axis, using the kinetic energy of high-speed rotation annularity tool, the abrasives in tool tip as the main cutting edge to remove materials and the abrasives in the outside surface of tool as a minor cutting edge to sharpen the processed surface. Comparing with concentric axial turning-grinding, eccentric axial turning-grinding has higher efficiency. The result indicated that cutting thickness and feed rate could be more than 5~10mm and 200mm/min respectively in a cutting, realizing high-efficiency, low-cost processing of engineering ceramics. According to axial force, chips’ shape and damage degree of surface to be processed, obtaining the proper feed rate range. Removal mechanism analyses showed that both median/radial cracks and lateral cracks occurred in the part to be removed, and the intensity of the processed part had little destroyed, only needing adjust axial force to control the length of transverse cracks.