Role of Gd addition on machinability of Al-15%Mg2Si in-situ composite during dry turning

Recently, Al-Mg2Si in-situ composites have achieved considerable attention due to their excellent physical and mechanical properties. In fact, there are some limitations of knowledge regarding the machinability characteristics of these composites - particularly when being inoculated with rare earth additions. This study in turn aimed to investigate the influence of machining parameters as well as Gd addition on the machinability of Al-15%Mg2Si composite. To examine the effect of modifier (1.0 wt. % Gd) and machining parameters (feed rate, cutting speed), microstructural evolution, surface roughness (Ra) and cutting force (Fc) were evaluated during dry turning. The results revealed that Gd addition as modifier element led to better surface roughness and higher cutting force owning to the modification of Mg2Si particle structure as well as the formation of Gd intermetallic compounds.

Wear Behavior of In Situ Mg2Si Particle-Dispersed Magnesium Alloys

Magnesium alloys, in which the in-situ Mg2Si particles were dispersed, were fabricated by a casting process, and the dry sliding wear behavior of the alloys was investigated. Optical microscopy revealed that the polygonal Mg2Si particles were homogeneously dispersed in the alloys. Mg2Si particle volume fractions in the alloys were 7 and 11 vol%. Although the wear loss of the alloy decreased due to the particle-dispersion, there was no difference in the wear loss between the alloys with different volume fractions. The worn surfaces of the particle-dispersed alloys were covered with the crumbled Mg2Si particles, which would prevent seizure between the alloy and the steel counterpart, leading to an improvement in the wear resistance of the alloy. The particle-dispersion slightly decreased the scatter of the coefficient of friction during the wear for the low sliding speed and load, but the effect of the dispersion was not clearly observed for the high speed and load.

Research on Wear Resistance of Mg2Si Reinforced Hypereutectic Al-Si Alloy Composite

Mg2Si particle reinforced hypereutectic Al-Si composite was prepared by casting, and the microstructure and wear resistance of the composite were researched. The results indicated that the morphology of Mg2Si obviously changed with Mg2Si contents increasing, in which the morphology of Mg2Si in the composite had changed from polygon block to characters like and finally became coarse dendrite. There were effects of Mg2Si content and morphology on the wear resistance in the composite, which had the higher hardness and better wear resistance at the suitable Mg2Si content.

Effect of Electromagnetic Stirring on Morphology Evolution of Mg2Si in Hypereutectic Al-Si Alloy Composite

Mg2Si reinforced hypereutectic Al-Si composite was prepared and the effects of electro- magnetic stirring on Mg2Si particle in the composite were researched. The results indicated that there were the important effects of electromagnetic stirring on size and morphology of the particle in the composite. The morphology and size of the particle in the composite were obviously improved by electromagnetic stirring. In comparison with the sample without isothermal holding, the size of the particle isothermally held slightly increased under the same stirring condition, but the roundness of the particle was improved. After isothermal holding, the mechanical properties of the composite prepared by electromagnetic stirring were improved to some extent.

Microstructure and Properties of In Situ Al-Si-Mg2Si Composite Prepared by Melt Superheating

Mg2Si particle reinforced in-situ Al-Si composite is prepared by melt superheating, and the microstructure and properties of the composite are researched. The results indicate that it is feasible that the melt superheating is applied to preparing Mg2Si particle reinforced in-situ Al-Si composite, and the suitable preparing parameters of melt superheating on the alloy are obtained. When the superheating temperature is 860°C and holding time is 25 min, the average size of Mg2Si particle in the alloy will be reduced to 11μm compared with 34μm without melt superheating, and the mechanical properties of the composite is obviously improved.

Hypereutectic Al-Si-Mg In Situ Composite Prepared by Melt Superheating

Mg2Si particle reinforced hypereutectic Al-Si-Mg alloy composite is prepared by melt superheating, and the effects of the main processing parameters, such as superheating temperature and holding time, on the microstructure of the composite are studied. The results indicate that it is feasible to prepare Mg2Si particle reinforced Al-18%Si-Mg alloy composite by melt superheating. The suitable preparing parameters of melt superheating on the alloy are obtained. When the superheating temperature is 860°C and holding time is 25 min, the average size of Mg2Si particle in the alloy will be reduced to about 11μm compared with 34μm without melt superheating.