Papers by Author: Peng Ju Xue

Abstract: Ti6Al4V component has been formed by hot isostatic pressing (HIPping) using internal graphite mould with Ni isolation layer. The shape of the graphite had no deformation after HIPping. The Ni isolation layer with a thickness of approximately 5μm on graphite before HIPping was diffused into the dense Ti6Al4V component surface and formed a uniform, compact and crack free layer with a thickness of approximately 100μm after HIPping. The Ni diffusion layer is not damaged after removing the graphite mould by unpolluted sandblasting. The interface topography and the elements diffusion have been assessed and it is found that the non-machined surface of Ti6Al4V component was improved by using graphite mould than those used mild steel. The roughness of non-machined surface after removing the graphite mould by sandblasting is Ra=1.6μm, and the roughness of non-machined surface after removing the mild steel by acid pickling is Ra=10.8μm. It is concluded that graphite mould could be used for the HIPping process to produce complex-shaped components.

Abstract: Near-net-shaping hot isostatic pressing (NNS-HIP) method was used for once-forming complex monolithic Ti6Al4V alloy bladed disks manufacturing. The complex monolithic bladed disks were formed successfully in a near-net-shape manner using the proposed HIP mold scheme in this study. The results showed that there were fine and homogeneous strip α+β phases and no obvious pores or cracks were detected. A "layered" phenomenon was observed in as-built part microstructure. The tensile strength value of specimens from the NNS-HIP bladed disks in the same furnace reached 900MPa, which was higher than the values of parts manufactured using casting and forging processes. The fracture morphology analysis showed that the sample had a ductile fracture. This study provides a reference to the NNS-HIP for the bladed disk parts manufacturing.

Abstract: Selective Laser Melting (SLM) technology can be used to fabricate plastic mould with complex conformal cooling channels directly and rapidly. In this paper, 316L stainless steel powders were used to produced a mould with an emphasis on attaining excellent mechanical properties.The precision, density and mechanical properties of parts were studied. Simulation and experimental results showed: the mould manufactured by SLM reveals good accuracy and performance, and the cooling efficiency of conformal cooling channels in mould has been greatly improved and the uniformity of cooling has been also upgraded.