Face Grinding Surface Quality of High Volume Fraction SiC_(p)/Al Composite Materials

The existing research on SiC_(p)/Al composite machining mainly focuses on the machining parameters or surface morphology.However,the surface quality of SiC_(p)/Al composites with a high volume fraction has not been extensively studied.In this study,32 SiC_(p)/Al specimens with a high volume fraction were prepared and their machining parameters measured.The surface quality of the specimens was then tested and the effect of the grinding parameters on the surface quality was analyzed.The grinding quality of the composite specimens was comprehensively analyzed taking the grinding force,friction coefficient,and roughness parameters as the evaluation standards.The best grinding parameters were obtained by analyzing the surface morphology.The results show that,a higher spindle speed should be chosen to obtain a better surface quality.The final surface quality is related to the friction coefficient,surface roughness,and fragmentation degree as well as the quantity and distribution of the defects.Lower feeding amount,lower grinding depth and appropriately higher spindle speed should be chosen to obtain better surface quality.Lower feeding amount,higher grinding depth and spindle speed should be chosen to balance grind efficiently and surface quality.This study proposes a systematic evaluation method,which can be used to guide the machining of SiC_(p)/Al composites with a high volume fraction.

Microstructure and Mechanical Properties of FeCoNiCrAl x High-entropy Alloys by Selective Laser Melting

In this study,the thermal analysis theory of selective laser melting(SLM)was introduced,and different high-entropy alloy(HEA)specimens were prepared using the SLM technology.The effects of different powder sizes,elemental contents,and process parameters on the microstructure and mechanical properties of FeCoNiCrAl x HEA specimens fabricated using SLM were analyzed.Moreover,hardness and tensile tests of these high-entropy alloys were performed.The results showed that with increasing laser power and hatch spacing,the hardness of the specimens initially increased and subsequently decreased;it also increased with increasing scanning speed.The FeCoNiCrAl 0.5 HEA specimens prepared using fine powder exhibited better tensile properties,followed by FeCoNiCrAl 0.8 HEA.However,the FeCoNiCrAl 0.5 HEA prepared using coarse powder exhibited the poorest tensile properties.A comparison of the tensile properties of the specimens at different heights revealed that the specimens formed at the middle height exhibited improved tensile properties.