Most of the materials used in the industry of aero-engine components generally consist of titanium alloys. Advanced materials, because of their excellent combination of high specific strength, light weight and general corrosion resistance. In fact, chemical wear resistance of aero-engine alloy provides a serious challenge for cutting tool material during the machining process. The reduction in cutting temperature distributions leads to an increase in tool life and a decrease in wear rate. Hence, the chip morphology and segmentation play a predominant role in determining machinability and tool wear during the machining process. The result of low thermal conductivity and diffusivity of this alloy is in the concentration of high temperatures at the tool-work-piece and tool-chip interface. Consequently, the chip morphology is very important in the study of machinability of metals as well as the study of cutting tool wear. Otherwise, the result will be accelerating tool wear, increasing manufacturing cost and time consuming. Manuscript profile

The output error of the globoidal cam mechanism can be considered as a relevant indicator of mechanism performance, because it determines kinematic and dynamical behavior of mechanical transmission. Based on the differential geometry and the rigid body transformations, the mathematical model of surface geometry of the globoidal cam is established. Then we present the analytical expression of the output error (including the transmission error and the displacement error along the output axis) by considering different manufacture and assembly errors. The effects of the center distance error, the perpendicular error between input and output axes and the rotational angle error of the globoidal cam on the output error are systematically analyzed. A globoidal cam mechanism which is widely used in automatic tool changer of CNC machines is applied for illustration. Our results show that the perpendicular error and the rotational angle error have little effects on the transmission error but have great effects on the displacement error along the output axis. This study plays an important role in the design, manufacture and assembly of the globoidal cam mechanism. Manuscript profile

Silica refractory bricks are used especially in the metallurgical industries, due to desirable properties such as particularly their high melting point and their rigidity and strength at high temperatures. In this research, different amount of SiC were added to Silica refractory containing different binders such as Borax, Boric acid, Calcium nitride, Sodium tri poly phosphate, Sodium hexametaphosphate (SHMP) and lime are added. Physical properties (density and porosity), mechanical properties (cold crush strength, CCS) and microstructure were studied. This study indicated that SiC improves the physical and mechanical properties. In general, increasing SiC with different binders improve the mechanical and compaction in the samples. Silica refractory sample containing 20%wt. SiC and 5% wt. borax as a binder had the best results of mechanical strength and compaction. In this sample, glassy phases formed fills the voids and increasing temperature between particles. In fact, glass phase formation increase compaction, density, and strength. Manuscript profile

Manufactured single crystal components using Ni-base super alloys are routinely used in the hot sections of aero engines and industrial gas turbines due to their outstanding high temperature strength, toughness and resistance to degradation in corrosive and oxidative environments. To control the quality of the single crystal turbine blades, particular attention has been paid to grain selection, which is used to obtain the single crystal morphology from a plethora of columnar grains. For this purpose, different designs of grain selectors are employed and the most common type is the spiral grain selector. A typical spiral grain selector includes a starter block and a spiral (helix) located above. It has been found that the grains with orientation well aligned to the thermal gradient survive in the starter block by competitive grain growth while the selection of the single crystal grain occurs in the spiral part. In the present study, 2Dspiral selectors with different geometries were designed and produced using a state-of-the-art Bridgeman Directional Solidification casting furnace to investigate the competitive growth during grain selection in 2d grain selectors. The principal advantage of using a 2-Dselector is to facilitate the wax injection process in investment casting by enabling significant degree of automation. The directional solidification process for obtaining single crystal component for Nickel Super alloys based on the competitive growth in 2D and 3D single crystal grain selector was experimentally investigated for various geometries. Transverse sections of the grain selectors using optical and EBSD microscopy techniques were observed to understand the competitive grain growth process. Manuscript profile

In this study; utilizing the elastic matrix ball has higher processing efficiency and better superficial quality than traditionalgrinding. The diversity of elastic abrasive tool characteristics contact with bend surface results in irregular wear abrasion，and abrasive tool machining status gets complicated. There is no theoretical interpretation of parameters affecting the grinding accuracy. Because of corrosion resistance, wear resistance and other characteristics of M200 material, it is often used as a material in aerospace precision components. In the study, grinding and polishing experiments has been carried out by using material of M200 to theoretically show the relationship between stress magnitude and grinding efficiency, and to predict the optimal combination of grinding parameters for effective grinding. Just in order to achieve the high abrasion resistance features of M200, the micro-contact of elastic ball abrasive tool (Whetstone) was analyzed, mathematical methods were used todeduce the functional relationship between residual peak removal rate and the main parameters which impact the grinding accuracy on the plane case. Thus they lay the foundation for the study of elastic abrasiveprediction and compensation. Manuscript profile