Experiment on fluid regime under different rotate velocity in physical simulation of titanium vertical centrifugal casting

Yajun Yin,Xin Peng,Gen Xiao,Jianxin Zhou,Peng Wan,Xiaoyuan Ji,Xiwang Qie,Xu Shen

doi:10.1007/s00170-021-08516-y

Abstract

In this paper, the physical simulation of filling process of vertical centrifugal casting (VCC) of complex titanium alloy casting was studied. Combined with the mature PTV particle tracking technology, the high-speed photography pictures of the filling process of VCC at different rotational speeds were obtained. The trajectory and velocity information of tracer particles in the rotating flow field were obtained by the corresponding analysis software. Then, through the analysis and modeling of quantitative experimental data, the flow behavior characteristics and movement law of titanium alloy melt in the mold cavity under different mold speeds were studied. The results show that: 1. When the mold is still, the front edge of the filling fluid forms a curved surface with the curvature center pointing to the outside of the mold; when the mold rotates, the front edge of the liquid flow forms a curved surface with the curvature center pointing to the inside of the mold; 2. With the increase of the mold rotation speed, the speed of the fluid filling the mold increases significantly; when the rotational speed is greater than 120 rpm, the fluid still has a certain driving force in the mold center far away from the gate; it is good for filling the inner corner of mold with fluid; and 3. When the rotational speed of centrifugal casting of titanium alloy reaches 45 rpm or above, typical turbulent vortices appear in the wake; with the increase of rotating speed to 180 rpm, the average curvature radius of turbulent vortices first increases and then decreases, and reaches the minimum value of 0.67 cm at 120 rpm.

Highlights

Vertical centrifugal casting (VCC) is one of the important technologies for titanium alloy precision casting (Jianghong et al, 2017)
The results show that PTV method can well describe the movement of gas-solid two-phase flow. (Thomas Hagemeier et al, 2015; zhaochen Jiang et al, 2018) C.E.Estrada-Perez et al studied the turbulent flow of HFE-301 in a rectangular channel by time-resolved particle tracking velocimetry, and obtained the characteristic values of its twodimensional velocity field and turbulence intensity
When the mold is still, the front edge of the filling fluid forms a curved surface with the curvature center pointing to the outside of the mold; when the mold is rotating, the front edge of the liquid flow forms a curved surface with the curvature center pointing to the inside of the mold

Summary

Introduction

Vertical centrifugal casting (VCC) is one of the important technologies for titanium alloy precision casting (Jianghong et al, 2017). Physical simulation experiment is an important means to study the filling process of titanium alloy. Many researchers have carried out a series of physical simulation experiments on the fluid filling process of centrifugal casting. Prasad et al Carried out cold simulation experiments with transparent water and 140ep oil with different viscosities, and studied the application of different rotational speeds on cylinder castings. Wu Shiping deduced the physical similarity model of titanium alloy VCC process to simulate the filling flow behavior of titanium alloy fluid under different gating systems and rotating speeds. (Changyun L, 2006) Ren et al Studied the micro scale liquid metal filling flow mode in centrifugal casting process through physical simulation experiments. The results show that with the increase of rotating speed, the time required for fluid to reach the peak filling rate decreases sharply (Ren m x et al, 2014)

Methods

Results

Conclusion