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Introduction It is well known that the existence of pores can act as crack initiation sites causing stress concentration, reduce the load bearing area, and detriment static/dynamic mechanical properties of the sintered part
[1, 2] Mechanical properties of porous materials with pores inside are strongly dependent on the amount, size, distribution, and shape of pores.
There have been a large numbers of researches on the effect of porosity on the mechanical properties of sintered parts inevitably containing pore for a long time. [3~6] The majority of the researches were, however, focused on the parts made by conventional powder metallurgy mainly consisting of pressing and sintering, in which the systematic control of pore shape and microstructure is inherently difficult.
(6) It should be noted in the present model that the initial stacking structure, i.e. the initial porosity �i affects the strength of sintered parts even with the same porosity.
Haynes, The Mechanical Bchaviour of Sintered of Sintered Metals, (Freund Pub., London, UK 1981)

Study of Interfacial Bonding Strength of Coat based on XRD Dejun Kong1,a ,Yongkang Zhang1,2,b , Aixin Feng 1 , Jinzhon Lu 1 and Tao Ge1 1 School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China 2 School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China a kong-dejun@163.com, bykzhang@ujs.edu.cn Keywords: Interfacial bonding strength, X-ray diffraction (XRD), Coat, Residual stress Abstract.
Introduction Coat technology is one of the important means to increase material surface performances, such as wearability, corrosion resistance, thermal resistance, fatigue resistance, radiation resistance and special properties of light, heat and electricity [1-3].
Residual stress is a widespread phenomenon during coat process, and is one of the main factors which effect bonding strength between coat and matrix [4].
Its hardness is above HRC65 after quenching and annealing of removing residual stress, TiN coat is deposited on ceramic cutting tool by PVD (Physical vapor deposition), and their mechanical properties are shown as Table 1 [7-8].
Table 1 Mechanical properties of Si3N4 substrate and TiN coat Material Expansion coefficient [K-1] Elasticity module [GPa] Density [g/cm 3] Si3N4 3.35×10-6 300 3.21 TiN 8.0×10-6 450 5.44 Test Device.

Properties of MSFAC Long-term Exposure to Sodium Sulfate Solution Liyun Pana, Jiandong Liub, Lun Lic and Xiaoke Lid School of Civil Engineering and Communication, North China University of Water Resources and Electric Power, Zhengzhou 450011, China aply67@ncwu.edu.cn, b971071615@qq.com, c190656296@qq.com, dlixk@ncwu.edu.cn Keywords: concrete; machine-made sand; fly ash; sodium sulfate attack; sulfate-ion concentration; chemical titration method.
Introduction Sulfate attack on concrete is a complex physical and chemical process which is affected by many factors.
The reasons are that some different characteristics such as coarse surface, angular shapes, and large content of stone powder of the machine-made sand compared with the natural river sand result in some different properties of concrete [8, 9].
Ordinary silicate cement of grade 42.5, machine-made sand, crushed limestone and F-class fly ash with lower content of calcium were used; their physical, chemical and mechanical properties are listed in Table 1 to Table 5 respectively.
Table 1 Physical and mechanical properties of cement Grade Fineness (%) Water content of standard density (%) Setting time (min) Compressive strength (MPa) Tensile strength (MPa) Initial Final 3d 28d 3d 28d 42.5 4.6 26.74 208 247 18.8 57.5 4.7 8.7 Table 2 Chemical composition of cement Chemical composition SiO2 Al2O3 Fe2O3 CaO f-CaO MgO SO3 K2O Na2O Alkali Weight percent (%) 31.43 12.43 3.34 41.28 0.76 4.25 3.22 0.80 0.43 0.97 Table 3 Properties and chemical combinations of fly-ash (%) Fineness Ignition loss (%) Water demand ratio (%) SO3 MgO SiO2 Fe2O3 Al2O3 CaO Na2O K2O 13.6 5.17 100 0.50 1.47 52.91 4.85 26.91 4.7 0.42 1.60 Table 4 Physical properties of machine-made sand Series (mm) Fineness modulus Apparent density (kg/m3) Bulk density (kg/m3) Closed volume density (kg/m3) Content of stone-powder (%) 0~4.75 3.5 2720 1475 1700 4.6 Table 5 Physical properties of coarse aggregate Series (mm) Apparent density (kg/m3) Bulk density (kg/m3) Crush index (%) Mud content

Introduction The Al-SiC composite material has a high strength to weight ratio, low coefficient of thermal expansion, low density, enhanced temperature strength, good dimensional stability, highly thermal resistance, highly abrasion resistance, good fatigue resistance, good physical properties and excellent mechanical properties, it is widely used in the aerospace, automotive, military, electronics, sports equipment and other fields [1-10].
Material’s specific physical and mechanical properties are shown in Table 2.
Due to the wide range of various factors, this test select a four-factor five-level full central composite design, the central composite design factor number is 4, the total number of tests is 31, 16 cubic points, the center of the cube point is 7, and 8 pivot point.
Response surface methodology can take the interaction between the various factors into account, to establish a more accurate secondary or higher-order regression model.
Analysis of factors influencing dry sliding wear behaviour of Al/SiC brake pad tribosystem.

In the present brief communication we extend the discussion on the mechanical properties of metals produced by severe plastic deformation.
The accent is placed on the mechanisms of strengthening and the role of different metallurgical factors in strengthening.
Hence, the materials employed in the present study are supposed to involve all these mechanisms in various combinations, which is useful to clarify the role of individual constituent mechanisms in the resultant properties of UFG SPD metals.
Surely, the number of passes which is required to form the high-angle grain boundaries is different for different materials, being dependent on various metallurgical factors such as the stacking fault energy, for instance.
It is worth noticing that the strain hardening exponent n is the same for both K18 alloys, i.e. strengthening in Au-25Ag and AuAgCu occurs in the essentially same way despite considerably different properties of solid solutions.

In addition, material micro-structural barrier related parameter is introduced to characterize the significant micro-structural affecting effects.
Chemical composition of the base metal and the electrodes for weld metal and monotonic mechanical properties see reference [5].
The cracks in these zones might affect the DESFC behaviour.
energy utilized factor in the MSC regime; G2, K2, and � 2 are initial growth rate, cyclic strain energy strengthening factor, and cyclic strain energy utilized factor in the PSC regime; aT is half DESFC length corresponding to the maximum micro-structural barrier.
And a material micro-structural barrier related parameter is introduced to characterize the significant micro-structural affecting effects.

Corrosion morphology image is one of the most important features to evaluate corrosiveness of aluminum alloy, it adversely affects the security and integrity of the aircraft structure [1, 2].
Currently, no studies are found about the corrosive characteristics and mechanical properties for the shot peening aluminum alloy corrosion.
Its mechanical properties are as follows: tensile strength is 510MPa, yield strength is 441MPa, elongation rate is 8% and Young’s modulus of elasticity is 71.7GPa.
Table 1 Shot peening parameters of aluminum alloy LC4 Factors Shot Flow [kg/min] Nozzle Distance [mm] Actual Intensity [A] Saturation Time[s] Parameters 5.4 80 0.006 9 Corrosion treatments.
In addition, it can also seen from Fig.3, stress distribution is affected by the relative position of pits obviously.

As one of the key techniques of the popularization for MEMS, MIM has many advantages such as low production cost, shaping complexity, material multi-applicability, good tolerance and mechanical properties, etc [3].
Polymer plastification method has significant effect on the melt flow properties.
All these problems should be solved gradually for getting good melt flow properties.
The basic properties are shown in Tab.2.
Tab.2 Properties of HDPE-8008 Properties Density(g/cm3) Specific heat(J/kg·K) Melt point(°C) values 0.946 2303 135 Procedure 1) Polymer ultrasonic plastification with the parameters as shown in Tab.3.

The temporal resolution of rainfall data usually available for practical applications is often lower than the data required for the design procedures or mathematical models application, greatly affecting their reliability [1].
Many factors affect the characteristics of a hydrological response, both in rural and in urban catchments; among these are the requirements of the rainfall data to be used as inputfor the rainfall–runoff models.
Description of the instrument Meteorological monitoring is actually carried out by means of consolidated technologies mainly based on mechanical sensors connected with digital data loggers used for collecting and transferring data.
Large errors may be produced at low rainfall intensity because of the mechanical inertia of the bucket.
Freni, Estimation of sub-hourly DDF curves using scaling properties of hourly and sub-hourly data at partially gauged site.

It affects the quality of slab, especially the formulation of cracks on the surface, and also determines whether the steel leaking occurs during production.
The property parameters of steel in high temperature change according to the temperature.
For calculating convenience, some unimportant factors are omitted, and assumptions are made as follows: (1) The heat transfer in the slab pulling direction is omitted, because the quantity of heat transfer in this direction accounts for 3 to 6 % of total quantity of heat
Thermal property parameter.
However, the creep deformation affects little on the thermal stress, it can be omitted.